131 files changed, 3139 insertions, 1843 deletions
diff --git a/Makefile b/Makefile
index 6697fc6..84244de 100644
--- a/Makefile
+++ b/Makefile
@@ -1,24 +1,19 @@
 include config.mk
 
+CDIRS := boot device initrd klib memory task syscall
+CDIRS += memory/alloc
+CDIRS += boot/$(TARGET_BOOTLOADER)
+CDIRS += arch/$(TARGET_MACHINE)
+
 CFILES := $(wildcard *.c)
-CFILES += $(wildcard */*.c)
-CFILES += $(wildcard boot/$(TARGET_BOOTLOADER)/*.c)
-CFILES += $(wildcard arch/$(TARGET_MACHINE)/*.c)
-CFILES += $(wildcard arch/$(TARGET_MACHINE)/*/*.c)
+CFILES += $(foreach dir, $(CDIRS), $(wildcard $(dir)/*.c))
 
 SFILES := $(wildcard *.S)
-SFILES += $(wildcard */*.S)
-SFILES += $(wildcard arch/$(TARGET_MACHINE)/*.S)
-SFILES += $(wildcard arch/$(TARGET_MACHINE)/*/*.S)
+SFILES += $(foreach dir, $(CDIRS), $(wildcard $(dir)/*.S))
 
 OBJFILES := $(patsubst %.c,%.o,$(CFILES))
 OBJFILES += $(patsubst %.S,%.o,$(SFILES))
 
-DFILES := $(wildcard *.d)
-DFILES += $(wildcard */*.d)
-DFILES += $(wildcard arch/$(TARGET_MACHINE)/*.d)
-DFILES += $(wildcard arch/$(TARGET_MACHINE)/*/*.d)
-
 BIN := jove.elf
 
 all: $(BIN)
diff --git a/arch/arch.h b/arch/arch.h
deleted file mode 100644
index 6e569fd..0000000
--- a/arch/arch.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef JOVE_ARCH_H
-#define JOVE_ARCH_H 1
-
-extern void serial_setup(void);
-
-extern void arch_tables_setup(void);
-
-#endif
diff --git a/arch/x86_64/cpu.c b/arch/x86_64/cpu.c
new file mode 100644
index 0000000..d088fcd
--- /dev/null
+++ b/arch/x86_64/cpu.c
@@ -0,0 +1,35 @@
+#include "arch/cpu.h"
+#include "arch/x86_64/msr.h"
+
+extern void _syscall_entry(void);
+
+extern void idt_init();
+
+void
+cpu_setup(void)
+{
+    idt_init();
+
+    cpu_arch_enable_sce();
+    cpu_set_syscall_entry((void*)_syscall_entry);
+}
+
+void cpu_arch_enable_sce(void)
+{
+    msr_efer_t feat = msr_efer_read();
+    feat.sce = 1;
+    msr_efer_write(feat);
+
+    msr_star_t star = msr_star_read();
+    star.kcs = 0x08;
+    star.ucs = 0x18;
+    msr_star_write(star);
+}
+
+void
+cpu_set_syscall_entry(void *ptr)
+{
+    msr_lstar_t lstar = (msr_lstar_t)ptr;
+    msr_lstar_write(lstar);
+}
+
diff --git a/arch/x86_64/cpu.h b/arch/x86_64/cpu.h
deleted file mode 100644
index 942c8d9..0000000
--- a/arch/x86_64/cpu.h
+++ /dev/null
@@ -1,13 +0,0 @@
-#ifndef ARCH_x86_64_CPU_H
-#define ARCH_x86_64_CPU_H 1
-
-#include <stdint.h>
-
-struct Registers
-{
-    uint64_t r15, r14, r13, r12, r11, r10, r9, r8;
-    uint64_t bp, di, si, dx, cx, bx, ax;
-    uint64_t ip, cs, flags, sp, ss;
-};
-
-#endif
diff --git a/arch/x86_64/elf.c b/arch/x86_64/elf.c
deleted file mode 100644
index 969cbf0..0000000
--- a/arch/x86_64/elf.c
+++ /dev/null
@@ -1,55 +0,0 @@
-#include "elf.h"
-#include "lib/string.h"
-#include "usr/elf.h"
-#include "io/log.h"
-#include "mem/memory.h"
-
-void*
-elf_load(const void *data, size_t len)
-{
-    if(data == NULL) return NULL;
-    if(len < 4) return NULL;
-
-    struct ELF_header *ehdr = (struct ELF_header*)data;
-    if(ehdr->e_ident[EI_MAG0] != E_IDENT_MAG0 &&
-            ehdr->e_ident[EI_MAG1] != E_IDENT_MAG1 &&
-            ehdr->e_ident[EI_MAG2] != E_IDENT_MAG2 &&
-            ehdr->e_ident[EI_MAG3] != E_IDENT_MAG3)
-        return NULL;
-
-    if(ehdr->e_ident[EI_CLASS] != E_IDENT_CLASS64) {
-        klogf("Jove does not support ELF files of class CLASS32\n");
-        return NULL;
-    }
-
-    if(ehdr->e_type != ET_EXEC) {
-        klogf("Jove does not support ELF files other than ET_EXEC\n");
-        return NULL;
-    }
-
-    uint64_t entry = ehdr->e_entry;
-    
-    size_t phdrc = ehdr->e_phnum;
-    struct ELF_phdr *phdrs = (struct ELF_phdr*)((uintptr_t)data + ehdr->e_phoff);
-    
-    for(size_t phdri = 0; phdri < phdrc; phdri++)
-    {
-        struct ELF_phdr *phdr = &phdrs[phdri];
-        void *pdata = (void*)phdr->p_vaddr;
-            
-        mem_ensure_range(
-                phdr->p_vaddr,
-                phdr->p_vaddr + phdr->p_memsz, 
-                (page_flags_t) {
-                    .present = true,
-                    .writeable = true,
-                    .useraccess = true,
-                    .executable = true
-                });
-        if(phdr->p_type == PT_LOAD)
-        {
-            memcpy(pdata, (void*)((uintptr_t)data + phdr->p_offset), phdr->p_filesz);
-        }
-    }
-    return (void*)entry;
-}
diff --git a/arch/x86_64/elf.h b/arch/x86_64/elf.h
deleted file mode 100644
index ebcd228..0000000
--- a/arch/x86_64/elf.h
+++ /dev/null
@@ -1,78 +0,0 @@
-#ifndef JOVE_ARCH_x86_64_ELF_H
-#define JOVE_ARCH_x86_64_ELF_H 1
-
-#include <stdint.h>
-
-#define EI_MAG0 0
-#define EI_MAG1 1
-#define EI_MAG2 2
-#define EI_MAG3 3
-#define EI_CLASS 4
-#define EI_DATA 5
-#define EI_VERSION 6
-#define EI_OSABI 7
-#define EI_ABIVERSION 8
-#define EI_PAD 9
-
-#define E_IDENT_MAG0 0x7F
-#define E_IDENT_MAG1 'E'
-#define E_IDENT_MAG2 'L'
-#define E_IDENT_MAG3 'F'
-
-#define E_IDENT_CLASS32 1
-#define E_IDENT_CLASS64 2
-
-#define ET_EXEC 0x02
-
-struct ELF_header
-{
-    uint8_t e_ident[15];
-    uint16_t e_type;
-    uint16_t e_machine;
-    uint32_t e_version;
-    uint64_t e_entry;
-    uint64_t e_phoff;
-    uint64_t e_shoff;
-    uint32_t e_flags;
-    uint16_t e_ehsize;
-    uint16_t e_phentsize;
-    uint16_t e_phnum;
-    uint16_t e_shentsize;
-    uint16_t e_shnum;
-    uint16_t e_shstrndx;
-};
-
-#define PT_NULL 0
-#define PT_LOAD 1
-
-#define PF_X 1
-#define PF_W 2
-#define PF_R 4
-
-struct ELF_phdr
-{
-    uint32_t p_type;
-    uint32_t p_flags;
-    uint64_t p_offset;
-    uint64_t p_vaddr;
-    uint64_t p_paddr;
-    uint64_t p_filesz;
-    uint64_t p_memsz;
-    uint64_t p_align;
-};
-
-struct ELF_shdr
-{
-    uint32_t sh_name;
-    uint32_t sh_type;
-    uint64_t sh_flags;
-    uint64_t sh_addr;
-    uint64_t sh_offset;
-    uint64_t sh_size;
-    uint32_t sh_link;
-    uint32_t sh_info;
-    uint64_t sh_addralign;
-    uint64_t sh_entsize;
-};
-
-#endif
diff --git a/arch/x86_64/elf_load.c b/arch/x86_64/elf_load.c
new file mode 100644
index 0000000..d7d1b29
--- /dev/null
+++ b/arch/x86_64/elf_load.c
@@ -0,0 +1,58 @@
+#include "arch/elf.h"
+#include "string.h"
+#include "memory.h"
+#include "print.h"
+
+uintptr_t
+elf_load(const void *data, size_t len)
+{
+    if(data == NULL) return 0;
+    if(len < 4) return 0;
+
+    elf_header_t *ehdr = (elf_header_t*)data;
+    if(ehdr->ei_mag[0] != EI_MAG0 ||
+       ehdr->ei_mag[1] != EI_MAG1 ||
+       ehdr->ei_mag[2] != EI_MAG2 ||
+       ehdr->ei_mag[3] != EI_MAG3) return 0;
+
+    if(ehdr->ei_class != EI_CLASS_64) {
+        kerrf("Jove does not support ELF files of class CLASS32\n");
+        return 0;
+    }
+
+    if(ehdr->e_type != ET_EXEC) {
+        kerrf("Jove does not support ELF files other than ET_EXEC\n");
+        return 0;
+    }
+
+    uint64_t entry = ehdr->e_entry;
+    
+    size_t phdrc = ehdr->e_phnum;
+    elf_phdr_t *phdrs = (elf_phdr_t*)((uintptr_t)data + ehdr->e_phoff);
+    
+    for(size_t phdri = 0; phdri < phdrc; phdri++)
+    {
+        elf_phdr_t *phdr = &phdrs[phdri];
+        void *pdata = (void*)phdr->p_vaddr;
+            
+        vm_ensure(
+                phdr->p_vaddr,
+                phdr->p_vaddr + phdr->p_memsz, 
+                (page_flags_t) {
+                    .present = true,
+                    .writeable = true,
+                    .useraccess = true,
+                    .executable = true
+                });
+
+        if(phdr->p_type == PT_LOAD)
+        {
+            kdbgf("PT_LOAD %#016X [%#016X] -> %#016X\n",
+                    (uintptr_t)data + phdr->p_offset,
+                    phdr->p_filesz,
+                    pdata);
+            memcpy(pdata, (void*)((uintptr_t)data + phdr->p_offset), phdr->p_filesz);
+        }
+    }
+    return entry;
+}
diff --git a/arch/x86_64/gdt.c b/arch/x86_64/gdt.c
index 07a8097..614ec30 100644
--- a/arch/x86_64/gdt.c
+++ b/arch/x86_64/gdt.c
@@ -1,24 +1,10 @@
-#include "tables.h"
-#include "tss.h"
+#include "arch/x86_64/gdt.h"
+#include "arch/x86_64/tss.h"
+#include "arch/processor.h"
+#include "string.h"
+#include "print.h"
 
-enum
-{
-    GDT_SEGMENT_KERNEL_NULL = 0,
-    GDT_SEGMENT_KERNEL_CODE,
-    GDT_SEGMENT_KERNEL_DATA,
-
-    GDT_SEGMENT_USER_NULL,
-    GDT_SEGMENT_USER_DATA,
-    GDT_SEGMENT_USER_CODE,
-
-    GDT_SEGMENT_TSS_LOW,
-    GDT_SEGMENT_TSS_HIGH,
-
-    GDT_SEGMENT_COUNT
-};
-
-__attribute__((aligned(0x1000)))
-static struct SegmentDescriptor s_gdtd[GDT_SEGMENT_COUNT] =
+static gdt_t s_baseline_gdt =
 {
     { 0 },  /* Kernel NULL */
     {       /* Kernel Code (64-bit RO EX DPL0) */
@@ -99,43 +85,40 @@ static struct SegmentDescriptor s_gdtd[GDT_SEGMENT_COUNT] =
     },
     { 0 }
 };
-static struct XDTR s_gdtr = {
-    .length = sizeof(s_gdtd) - 1,
-    .address = (uintptr_t)&s_gdtd
-};
 
-static struct TSS s_tss = {
-    
-};
-
-extern void x86_64_lgdt(struct XDTR *gdtr);
-extern void x86_64_flush_tss(void);
 void
-x86_64_load_gdt(void)
+gdt_setup(processor_t *proc)
 {
-    {
-        struct SegmentDescriptor *tss_lo = &s_gdtd[GDT_SEGMENT_TSS_LOW];
-        struct SegmentDescriptor *tss_hi = &s_gdtd[GDT_SEGMENT_TSS_HIGH];
-        uintptr_t tssb = (uintptr_t)&s_tss;
-        tss_lo->base_0_15 = tssb & 0xFFFF;
-        tss_lo->base_16_23 = (tssb >> 16) & 0xFF;
-        tss_lo->base_24_31 = (tssb >> 24) & 0xFF;
-        tss_hi->limit_0_15 = (tssb >> 32) & 0xFFFF;
-        tss_hi->base_0_15 = (tssb >> 48) & 0xFFFF;
+    memcpy(proc->_gdt, s_baseline_gdt, sizeof(gdt_t));
+    proc->_gdtr = (struct XDTR) {
+        .length = sizeof(gdt_t) - 1,
+        .address = (uintptr_t)&proc->_gdt
+    };
+    klogf("Processor %i GDT %#016X L%i\n", proc->id, proc->_gdt, proc->_gdtr.length);
+}
 
-        size_t tssl = sizeof(struct TSS) - 1;
-        tss_lo->limit_0_15 = tssl & 0xFFFF;
-        tss_lo->limit_16_19 = (tssl >> 16) & 0xF;
+void
+tss_setup(processor_t *proc)
+{
+    segment_descriptor_t *tss_lo = &proc->_gdt[GDT_SEGMENT_TSS_LOW];
+    segment_descriptor_t *tss_hi = &proc->_gdt[GDT_SEGMENT_TSS_HIGH];
+    uintptr_t tssb = (uintptr_t)&(proc->_tss);
+    tss_lo->base_0_15 = tssb & 0xFFFF;
+    tss_lo->base_16_23 = (tssb >> 16) & 0xFF;
+    tss_lo->base_24_31 = (tssb >> 24) & 0xFF;
+    tss_hi->limit_0_15 = (tssb >> 32) & 0xFFFF;
+    tss_hi->base_0_15 = (tssb >> 48) & 0xFFFF;
 
-        s_tss.iobp = sizeof(struct TSS);
-    }
+    size_t tssl = sizeof(struct TSS) - 1;
+    tss_lo->limit_0_15 = tssl & 0xFFFF;
+    tss_lo->limit_16_19 = (tssl >> 16) & 0xF;
 
-    x86_64_lgdt(&s_gdtr);
-    x86_64_flush_tss();
+    proc->_tss.iobp = sizeof(struct TSS);
 }
 
-void tss_set_rsp(uint8_t dpl, uintptr_t rsp)
+void
+tss_set_rsp(struct TSS *tss, uint8_t dpl, uintptr_t rsp)
 {
-    s_tss.rsp[dpl][0] = rsp & 0xFFFFFFFF;
-    s_tss.rsp[dpl][1] = (rsp >> 32) & 0xFFFFFFFF;
+    tss->rsp[dpl][0] = rsp & 0xFFFFFFFF;
+    tss->rsp[dpl][1] = (rsp >> 32) & 0xFFFFFFFF;
 }
diff --git a/arch/x86_64/idt.c b/arch/x86_64/idt.c
index 05dcf43..5ddda50 100644
--- a/arch/x86_64/idt.c
+++ b/arch/x86_64/idt.c
@@ -1,64 +1,25 @@
-#include "tables.h"
-#include "cpu.h"
-#include "lib/jove.h"
-#include "io/log.h"
+#include <stddef.h>
+#include "arch/x86_64/tables.h"
+#include "arch/x86_64/idt.h"
+#include "arch/processor.h"
+#include "print.h"
+#include "jove.h"
 
 PAGEALIGN
-static struct InterruptTrapGate s_idtd[48];
-static struct Registers *(*s_int_handlers[48])(struct Registers*);
-static struct XDTR s_idtr = {
-    .length = sizeof(s_idtd) - 1,
-    .address = (uintptr_t)&s_idtd
-};
+static interrupt_gate_t s_idtd[48];
 
 uint64_t __isr_err;
 uint64_t __isr_num;
 
-void
-int_set_handler(uint8_t code, struct Registers *(*handler)(struct Registers*))
-{
-    if(code >= 48) return;
-    s_int_handlers[code] = handler;
-}
-
-struct Registers*
-irq_handle(struct Registers *state)
-{
-    if(__isr_num < 48) {
-        if(s_int_handlers[__isr_num] != NULL) {
-            return s_int_handlers[__isr_num](state);
-        }
-    }
-    klogf("Interrupt %i\nerror code %#016X\n", __isr_num, __isr_err);
-    klogf("IP:  %#016X\n", state->ip);
-    klogf("AX:  %#016X\n", state->ax);
-    klogf("BX:  %#016X\n", state->bx);
-    klogf("CX:  %#016X\n", state->cx);
-    klogf("DX:  %#016X\n", state->dx);
-    klogf("SI:  %#016X\n", state->si);
-    klogf("DI:  %#016X\n", state->di);
-    klogf("BP:  %#016X\n", state->bp);
-    klogf("R8:  %#016X\n", state->r8);
-    klogf("R9:  %#016X\n", state->r9);
-    klogf("R10: %#016X\n", state->r10);
-    klogf("R11: %#016X\n", state->r11);
-    klogf("R12: %#016X\n", state->r12);
-    klogf("R13: %#016X\n", state->r13);
-    klogf("R14: %#016X\n", state->r14);
-    klogf("R15: %#016X\n", state->r15);
-    kpanic("Unhandled exception\n");
-    return state;
-}
-
 extern void x86_64_lidt(struct XDTR *idtr);
 void
-x86_64_load_idt(void)
+idt_init(void)
 {
     extern uintptr_t __isr_stubs[22];
     for(int i = 0; i < 22; i++)
     {
         uintptr_t base = __isr_stubs[i];
-        s_idtd[i] = (struct InterruptTrapGate){
+        s_idtd[i] = (interrupt_gate_t){
             .base_0_15 = (base & 0xFFFF),
             .segment_selector = 0x8,
             .ist = 0,
@@ -71,7 +32,14 @@ x86_64_load_idt(void)
             .base_32_63 = (base >> 32) & 0xFFFFFFFF,
             .resv = 0
         };
-        klogf("INT %2i : %#016X (%016X)\n", i, base, s_idtd[i]);
     }
-    x86_64_lidt(&s_idtr);
+}
+
+void
+idt_setup(processor_t *proc)
+{
+    proc->_idtr = (struct XDTR){
+        .length = sizeof(s_idtd) - 1,
+        .address = (uintptr_t)s_idtd
+    };
 }
diff --git a/arch/x86_64/int_handler.c b/arch/x86_64/int_handler.c
new file mode 100644
index 0000000..3674d1c
--- /dev/null
+++ b/arch/x86_64/int_handler.c
@@ -0,0 +1,52 @@
+#include "arch/x86_64/idt.h"
+#include "arch/processor.h"
+#include "print.h"
+#include "jove.h"
+#include "assert.h"
+#include <stddef.h>
+
+static int_handler_t s_handlers[48];
+
+int_state_t*
+irq_handle(int_state_t *state)
+{
+    if(__isr_num < 48) {
+        if(s_handlers[__isr_num] != NULL) {
+            return s_handlers[__isr_num](state);
+        }
+    }
+
+    klogf("Interrupt %i\nerror code %#016X\n", __isr_num, __isr_err);
+    int_state_print(state);
+    kpanic("Unhandled exception\n");
+    return state;
+}
+
+void 
+int_handler_set(uint8_t i, int_handler_t handler)
+{
+    assert(i < 48);
+    s_handlers[i] = handler;
+}
+
+int_handler_t 
+int_handler_get(uint8_t i)
+{
+    assert(i < 48);
+    return s_handlers[i];
+}
+
+void 
+int_state_print(int_state_t *state)
+{
+    if(!state) return;
+    klogf("IP:  %016p\n", state->ip);
+    klogf("AX:  %016p BX:  %016p\n", state->ax, state->bx);
+    klogf("CX:  %016p DX:  %016p\n", state->cx, state->dx);
+    klogf("SI:  %016p DI:  %016p\n", state->si, state->di);
+    klogf("SP:  %016p BP:  %016p\n", state->sp, state->bp);
+    klogf("R8:  %016p R9:  %016p\n", state->r8, state->r9);
+    klogf("R10: %016p R11: %016p\n", state->r10, state->r11);
+    klogf("R12: %016p R13: %016p\n", state->r12, state->r13);
+    klogf("R14: %016p R15: %016p\n", state->r14, state->r15);
+}
diff --git a/arch/x86_64/interrupt.h b/arch/x86_64/interrupt.h
deleted file mode 100644
index 9ae63f9..0000000
--- a/arch/x86_64/interrupt.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef JOVE_ARCH_INTERRUPT_H
-#define JOVE_ARCH_INTERRUPT_H 1
-
-#include "cpu.h"
-
-/**Register a handler for a specified interrupt code.
- * @param code interrupt to handle.
- * @param handler to call.*/
-void int_set_handler(unsigned char code, struct Registers *(*handler)(struct Registers*));
-
-#endif
diff --git a/arch/x86_64/kexec.c b/arch/x86_64/kexec.c
new file mode 100644
index 0000000..406e8e7
--- /dev/null
+++ b/arch/x86_64/kexec.c
@@ -0,0 +1,50 @@
+#include "tasking.h"
+#include "memory.h"
+#include "string.h"
+#include "arch/cpu.h"
+
+#define UMODE_STACK_TOP (USERLAND_MEMORY_LIMIT)
+#define UMODE_STACKW PAGE_SIZE
+
+static void*
+s_umode_stack(void)
+{
+    uintptr_t top = UMODE_STACK_TOP;
+    uintptr_t bottom = top - (UMODE_STACKW - 1);
+
+    vm_ensure(bottom, top, (page_flags_t) {
+        .present = true,
+        .writeable = true,
+        .useraccess = true,
+        .executable = false
+            });
+    return (void*)top;
+}
+
+static inline void*
+s_stack_push(void *sp, void *data, size_t len)
+{
+    sp = (void*)((uintptr_t)sp - len);
+    memcpy(sp, data, len);
+    return sp;
+}
+
+void
+kexec(void *ip, int kargc, char **kargv, int kenvc, char **kenvp)
+{
+    /* Allocate a page for the user stack. */
+    void *sp = s_umode_stack();
+    
+    intmax_t argc = kargc;
+    sp = s_stack_push(sp, &argc, sizeof(intmax_t));
+
+    /* TODO: Proper argv, envp*/
+    sp = s_stack_push(sp, &kargv, sizeof(char**));
+    
+    intmax_t envc = kenvc;
+    sp = s_stack_push(sp, &envc, sizeof(intmax_t));
+
+    sp = s_stack_push(sp, &kenvp, sizeof(char**));
+
+    umode_enter(ip, sp);
+}
diff --git a/arch/x86_64/msr.c b/arch/x86_64/msr.c
new file mode 100644
index 0000000..1891126
--- /dev/null
+++ b/arch/x86_64/msr.c
@@ -0,0 +1,67 @@
+#include "arch/x86_64/msr.h"
+
+void
+msr_write(uint32_t msr, uint64_t v)
+{
+    __asm__ volatile("wrmsr":: "a"(v), "d"(v >> 32), "c"(msr));
+}
+
+uint64_t
+msr_read(uint32_t msr)
+{
+    uint32_t lo, hi;
+    __asm__ volatile("rdmsr": "=a"(lo), "=d"(hi): "c"(msr));
+    uint64_t v = hi;
+    v = (v << 32) | lo;
+    return v;
+}
+
+void 
+msr_efer_write(msr_efer_t v)
+{
+    msr_write(MSR_EFER, *((uintptr_t*)&v));
+}
+
+msr_efer_t 
+msr_efer_read(void)
+{
+    uint64_t rawv = msr_read(MSR_EFER);
+    return *((msr_efer_t*)&rawv);
+}
+
+void 
+msr_star_write(msr_star_t v)
+{
+    msr_write(MSR_STAR, *((uintptr_t*)&v));
+}
+
+msr_star_t 
+msr_star_read(void)
+{
+    uint64_t rawv = msr_read(MSR_STAR);
+    return *((msr_star_t*)&rawv);
+}
+
+void 
+msr_lstar_write(msr_lstar_t v)
+{
+    msr_write(MSR_LSTAR, v);
+}
+
+msr_lstar_t 
+msr_lstar_read(void)
+{
+    return msr_read(MSR_LSTAR);
+}
+
+void
+msr_gsbase_write(uintptr_t gsbase)
+{
+    msr_write(MSR_GSBASE, gsbase);
+}
+
+uintptr_t
+msr_gsbase_read(void)
+{
+    return msr_read(MSR_GSBASE);
+}
diff --git a/arch/x86_64/page.c b/arch/x86_64/page.c
new file mode 100644
index 0000000..d816f66
--- /dev/null
+++ b/arch/x86_64/page.c
@@ -0,0 +1,173 @@
+#include "arch/x86_64/page.h"
+#include "klib/rbtree.h"
+#include "arch/processor.h"
+#include "string.h"
+#include "jove.h"
+#include "memory.h"
+#include "print.h"
+
+extern void *_kernel_end;
+
+struct PageDirectoryListEntry {
+    struct PageDirectoryListEntry *next;
+    page_directory_t pd;
+};
+
+struct PageStateCache {
+    page_directory_t *pd;
+    size_t pmli[4];
+    pmle_t *pml[4];
+} s_state_cache;
+
+const uintptr_t USERLAND_MEMORY_BASE = KiB;
+const uintptr_t USERLAND_MEMORY_LIMIT = 0x00007FFFFFFFFFFFULL;
+
+const uintptr_t PHYSMAP_MEMORY_BASE = 0xFFFF800000000000ULL;
+const uintptr_t PHYSMAP_MEMORY_LIMIT = PHYSMAP_MEMORY_BASE + (1 * GiB);
+
+const uintptr_t KERNEL_MEMORY_BASE = 0xFFFF800000000000ULL;
+const uintptr_t KERNEL_MEMORY_LIMIT = 0xFFFFFFFFFFFFFFFFULL;
+
+static size_t
+s_paging_pmli(size_t l, uintptr_t addr)
+{
+    size_t shift = (PAGE_SHIFT + (9 * l));
+    return (addr & (0x1FFULL << shift)) >> shift;
+}
+
+static pmle_t*
+s_paging_fetch_table(pmle_t *pml, size_t l, uintptr_t virt)
+{
+    size_t pmli = s_paging_pmli(l, virt);
+    if(s_state_cache.pmli[l] == pmli && s_state_cache.pml[l] != NULL)
+        return s_state_cache.pml[l];
+
+    pmle_t entry = pml[pmli];
+    bool entry_new = false;
+    if(!entry.p) {
+        entry_new = true;
+        entry.value = pm_alloc(1);
+        entry.p = 1;
+        entry.rw = 1;
+        entry.us = 1;
+        pml[pmli] = entry;
+    }
+    pmle_t *table = (pmle_t*)(pm_tovirt(entry.paddr << PAGE_SHIFT));
+    if(entry_new) memset(table, 0, PAGE_SIZE);
+
+    s_state_cache.pmli[l] = pmli;
+    s_state_cache.pml[l] = table;
+    return table;
+}
+
+static void
+s_paging_cache_tables(page_directory_t *pd, uintptr_t virt)
+{
+    pmle_t *pml4 = pd->pml;
+    if(s_state_cache.pd != pd) memset(&s_state_cache, 0, sizeof(s_state_cache));
+
+    pmle_t *pml3 = s_paging_fetch_table(pml4, 3, virt);
+    pmle_t *pml2 = s_paging_fetch_table(pml3, 2, virt);
+    pmle_t *pml1 = s_paging_fetch_table(pml2, 1, virt);
+}
+
+static pmle_t*
+s_paging_get_table(pmle_t *pt, size_t l, uintptr_t virt)
+{
+    if(pt == NULL) return NULL;
+    size_t pmli = s_paging_pmli(l, virt);
+    if(s_state_cache.pmli[l] == pmli && s_state_cache.pml[l] != NULL)
+        return s_state_cache.pml[l];
+
+    pmle_t entry = pt[pmli];
+    if(!entry.p) return NULL;
+    return (pmle_t*)(pm_tovirt(entry.paddr << PAGE_SHIFT));
+}
+
+page_mapping_t
+vm_pd_mapping_get(page_directory_t *pd, uintptr_t addr)
+{
+    spinlock_acquire(pd->lock);
+    page_mapping_t mapping = { 0 };
+    
+    pmle_t *pml4 = pd->pml;
+    if(s_state_cache.pd != pd) memset(&s_state_cache, 0, sizeof(s_state_cache));
+
+    pmle_t *pml3 = s_paging_get_table(pml4, 3, addr);
+    pmle_t *pml2 = s_paging_get_table(pml3, 2, addr);
+    pmle_t *pml1 = s_paging_get_table(pml2, 1, addr);
+    if(pml1 == NULL) goto release_return;
+
+    size_t pml1i = s_paging_pmli(0, addr);
+    pmle_t pml1e = pml1[pml1i];
+
+    mapping = (page_mapping_t) {
+        .phys = (pml1e.paddr << PAGE_SHIFT) & ~PAGE_MASK,
+        .pf = {
+            .present = pml1e.p,
+            .writeable = pml1e.rw,
+            .useraccess = pml1e.us,
+            .executable = !pml1e.xd
+        }
+    };
+release_return:
+    spinlock_release(pd->lock);
+    return mapping;
+}
+
+page_mapping_t vm_mapping_get(uintptr_t addr)
+{ return vm_pd_mapping_get(pd_current(), addr); }
+
+void
+mem_set_mapping_as(page_directory_t *pd, page_mapping_t mapping, uintptr_t virt)
+{
+    spinlock_acquire(pd->lock);
+    s_paging_cache_tables(pd, virt);
+    pmle_t *pml1 = s_state_cache.pml[0];
+    size_t pml1i = s_paging_pmli(0, virt);
+
+    pml1[pml1i] = (pmle_t) {
+        .p = mapping.pf.present,
+        .rw = mapping.pf.writeable,
+        .us = mapping.pf.useraccess,
+        .xd = !mapping.pf.executable,
+        .paddr = mapping.phys >> PAGE_SHIFT
+    };
+    spinlock_release(pd->lock);
+}
+
+void mem_set_mapping(page_mapping_t mapping, uintptr_t virt)
+{ mem_set_mapping_as(pd_current(), mapping, virt); }
+
+void
+vm_pd_ensure(page_directory_t *pd, uintptr_t from, uintptr_t to, page_flags_t flg)
+{
+    spinlock_acquire(pd->lock);
+    from &= ~(PAGE_SIZE - 1);
+    to += (to % PAGE_SIZE > 0 ? (PAGE_SIZE - (to % PAGE_SIZE)) : 0);
+
+    if(to < from) to = from;
+    size_t pages = (to - from) >> PAGE_SHIFT;
+    if(pages == 0) pages = 1;
+    for(size_t i = 0; i < pages; i++) {
+        uintptr_t waddr = from + (i << PAGE_SHIFT);
+        s_paging_cache_tables(pd, waddr);
+        pmle_t *pml1 = s_state_cache.pml[1];
+        size_t pml1i = s_paging_pmli(0, waddr);
+
+        if(!pml1[pml1i].p) {
+            physptr_t phys = pm_alloc(1);
+            pml1[pml1i] = (pmle_t) {
+                .p = flg.present,
+                .rw = flg.writeable,
+                .us = flg.useraccess,
+                .xd = !flg.executable,
+                .paddr = phys >> PAGE_SHIFT
+            };
+        }
+    }
+    spinlock_release(pd->lock);
+}
+
+void vm_ensure(uintptr_t from, uintptr_t to, page_flags_t flg)
+{ vm_pd_ensure(pd_current(), from, to, flg); }
diff --git a/arch/x86_64/paging.h b/arch/x86_64/page.h
index 28dfad2..28dfad2 100644
--- a/arch/x86_64/paging.h
+++ b/arch/x86_64/page.h
diff --git a/arch/x86_64/pagedirectory.c b/arch/x86_64/pagedirectory.c
new file mode 100644
index 0000000..cdfffeb
--- /dev/null
+++ b/arch/x86_64/pagedirectory.c
@@ -0,0 +1,138 @@
+#include "arch/page.h"
+#include "arch/processor.h"
+#include "klib/rbtree.h"
+#include "boot.h"
+#include "memory.h"
+#include "string.h"
+#include "print.h"
+
+PAGEALIGN static uint64_t s_kernel_initial_pml4[512];
+PAGEALIGN static uint64_t s_kernel_initial_pml3[2][512];
+PAGEALIGN static uint64_t s_kernel_initial_pml2[2][512];
+PAGEALIGN static uint64_t s_kernel_initial_pml1[2][512];
+static page_directory_t s_kernel_initial_pd;
+
+static rbtree_t s_page_directories;
+static intmax_t s_next_pdid = 0;
+
+page_directory_t*
+pd_new()
+{
+    page_directory_t newpd = {
+        .id = s_next_pdid++,
+        .phys = pm_alloc(1),
+    };
+    newpd.pml = (void*)pm_tovirt(newpd.phys);
+    for(size_t i = 256; i < 512; i++) {
+        pmle_t *kpe = &(s_kernel_initial_pd.pml)[i];
+        pmle_t *ppe = &(newpd.pml)[i];
+        *ppe = *kpe;
+    }
+
+    return rbtree_insert(&s_page_directories, newpd.id, &newpd);
+}
+
+static void
+s_pd_dup_pml(pmle_t *src, pmle_t *dest, size_t l, size_t i)
+{
+    pmle_t srce = src[i];
+    if(!srce.p) return;
+
+    dest[i] = srce;
+    dest[i].paddr = pm_alloc(1);
+    pmle_t dste = dest[i];
+
+    pmle_t *srct = (pmle_t*)pm_tovirt(srce.paddr << PAGE_SHIFT);
+    pmle_t *dstt = (pmle_t*)pm_tovirt(dste.paddr << PAGE_SHIFT);
+
+    if(l == 0) {
+        memcpy(dstt, srct, PAGE_SIZE);
+        return;
+    }
+
+    for(i = 0; i < 512; i++) {
+        dstt[i] = srct[i];
+        if(!srct[i].p) continue;
+        s_pd_dup_pml(srct, dstt, l - 1, i);
+    }
+}
+
+page_directory_t*
+pd_dup(page_directory_t *pd)
+{
+    page_directory_t *newpd = pd_new();
+    for(size_t i = 0; i < 256; i++) {
+        s_pd_dup_pml(pd->pml, newpd->pml, 3, i);
+    }
+    return newpd;
+}
+
+page_directory_t*
+pd_get(pdid_t pdid)
+{
+    return rbtree_find(&s_page_directories, pdid);
+}
+
+void 
+pd_switch(page_directory_t *pd)
+{
+    processor_t *pc = processor_current();
+    if(pc->pd == pd) return;
+    pc->pd = pd;
+    __asm__ volatile("movq %0, %%cr3":: "r"(pd->phys));
+}
+
+void
+vm_setup_early(void)
+{
+    memset(s_kernel_initial_pml4, 0, PAGE_SIZE);
+    memset(s_kernel_initial_pml3, 0, 2 * PAGE_SIZE);
+    memset(s_kernel_initial_pml2, 0, 2 * PAGE_SIZE);
+    memset(s_kernel_initial_pml1, 0, PAGE_SIZE);
+    s_kernel_initial_pd = (page_directory_t){
+        .phys = vm_tophys_koff((uintptr_t)&s_kernel_initial_pml4),
+        .pml = (pmle_t*)&s_kernel_initial_pml4,
+        .id = s_next_pdid++
+    };
+    processor_current()->pd = &s_kernel_initial_pd;
+
+    /* Map first few GiBs */
+    s_kernel_initial_pml4[256] =
+        vm_tophys_koff((uintptr_t)&s_kernel_initial_pml3[0])
+        | 3;
+    s_kernel_initial_pml3[0][0] =
+        vm_tophys_koff((uintptr_t)&s_kernel_initial_pml2[0])
+        | 3;
+    for(int i = 0; i < 512; i++) {
+        s_kernel_initial_pml2[0][i] = (i * (PAGE_SIZE * 512)) | 0x80 | 3;
+    }
+
+    size_t kernel_pml3e = (_kernel_virtual_base >> (30)) % 512;
+    size_t kernel_pml2e = (_kernel_virtual_base >> (21)) % 512;
+    size_t kernel_npages = ((((uintptr_t)&_kernel_end) - _kernel_virtual_base) >> 12) + 1;
+    klogf("Kernel has %i pages\n", kernel_npages);
+
+    /* Map kernel pages */
+    s_kernel_initial_pml4[511] =
+        vm_tophys_koff((uintptr_t)&s_kernel_initial_pml3[1]) | 3;
+    s_kernel_initial_pml3[1][kernel_pml3e] =
+        vm_tophys_koff((uintptr_t)&s_kernel_initial_pml2[1]) | 3;
+    s_kernel_initial_pml2[1][kernel_pml2e] =
+        vm_tophys_koff((uintptr_t)&s_kernel_initial_pml1[0]) | 3;
+    for(size_t i = 0; i < kernel_npages; i++) {
+        s_kernel_initial_pml1[0][i] = (i * PAGE_SIZE) + boot_kernel_physical_address | 3;
+    }
+ 
+    extern int_state_t *_pagefault_handler(int_state_t*);
+    int_handler_set(14, _pagefault_handler);
+    __asm__ volatile("mov %0, %%cr3":: "r"(s_kernel_initial_pd.phys));
+}
+
+void
+vm_setup(void)
+{
+    rbtree_new(&s_page_directories, page_directory_t);
+
+    processor_t *proc = processor_current();
+    pd_switch(pd_new());
+}
diff --git a/arch/x86_64/pagefault.c b/arch/x86_64/pagefault.c
new file mode 100644
index 0000000..5bba20b
--- /dev/null
+++ b/arch/x86_64/pagefault.c
@@ -0,0 +1,39 @@
+#include "arch/x86_64/idt.h"
+#include "arch/processor.h"
+#include "memory.h"
+#include "print.h"
+#include "jove.h"
+
+#include <stdbool.h>
+
+int_state_t*
+_pagefault_handler(int_state_t *state)
+{
+    extern uint64_t __isr_err;
+
+    uintptr_t fault_addr = 0;
+    __asm__ volatile("movq %%cr2, %0": "=r"(fault_addr));
+
+    if(fault_addr < USERLAND_MEMORY_LIMIT) {
+        // Check if there is an entry in the exception return table.
+        processor_t *proc = processor_current();
+        if(proc->ert_i > 0) {
+            state->ip = (uintptr_t)_exrtab_pop();
+            return state;
+        }
+    }
+
+    bool present = __isr_err & 1;
+    bool write = __isr_err & 2;
+    bool user = __isr_err & 4;
+
+    klogf("Page fault at %016X\n", fault_addr);
+    klogf("%s %s from a %s address\n", 
+            user ? "user" : "kernel",
+            write ? "wrote" : "read",
+            present ? "present" : "non-present");
+
+    int_state_print(state);
+    kpanic("Unhandled page fault\n");
+    return state;
+}
diff --git a/arch/x86_64/paging.c b/arch/x86_64/paging.c
deleted file mode 100644
index dc27ca2..0000000
--- a/arch/x86_64/paging.c
+++ /dev/null
@@ -1,257 +0,0 @@
-#include "paging.h"
-#include "interrupt.h"
-#include "io/log.h"
-#include "lib/jove.h"
-#include "lib/string.h"
-#include "lib/hashtable.h"
-#include "mem/memory.h"
-#include "boot/boot.h"
-
-extern void *_kernel_end;
-
-PAGEALIGN static uint64_t s_kernel_initial_pml4[512];
-PAGEALIGN static uint64_t s_kernel_initial_pml3[2][512];
-PAGEALIGN static uint64_t s_kernel_initial_pml2[2][512];
-PAGEALIGN static uint64_t s_kernel_initial_pml1[2][512];
-static intmax_t s_next_pdid = 0;
-static page_directory_t s_kernel_initial_pd;
-
-page_directory_t *current_page_directory;
-
-struct PageStateCache {
-    page_directory_t *pd;
-    size_t pmli[4];
-    pmle_t *pml[4];
-} s_state_cache;
-
-physptr_t
-mem_linear_tophys_koffset(uintptr_t virt)
-{
-    return (virt - boot_kernel_virtual_base) + boot_kernel_physical_address;
-}
-
-uintptr_t
-mem_phys_tolinear(physptr_t phys)
-{
-    return (uintptr_t)(phys + 0xFFFF800000000000ULL);
-}
-
-static size_t
-s_paging_pmli(size_t l, uintptr_t addr)
-{
-    size_t shift = (12 + (9 * l));
-    return (addr & (0x1FFULL << shift)) >> shift;
-}
-
-static pmle_t*
-s_paging_fetch_table(pmle_t *pml, size_t l, uintptr_t virt)
-{
-    size_t pmli = s_paging_pmli(l, virt);
-    if(s_state_cache.pmli[l] == pmli && s_state_cache.pml[l] != NULL)
-        return s_state_cache.pml[l];
-
-    pmle_t entry = pml[pmli];
-    bool entry_new = false;
-    if(!entry.p) {
-        entry_new = true;
-        entry.value = mem_phys_alloc(1);
-        entry.p = 1;
-        entry.rw = 1;
-        entry.us = 1;
-        pml[pmli] = entry;
-    }
-    pmle_t *table = (pmle_t*)(mem_phys_tolinear(entry.paddr << 12));
-    if(entry_new) memset(table, 0, PAGE_SIZE);
-
-    s_state_cache.pmli[l] = pmli;
-    s_state_cache.pml[l] = table;
-    return table;
-}
-
-static void
-s_paging_cache_tables(page_directory_t *pd, uintptr_t virt)
-{
-    pmle_t *pml4 = (pmle_t*)pd->virt;
-    if(s_state_cache.pd != pd) memset(&s_state_cache, 0, sizeof(s_state_cache));
-
-    pmle_t *pml3 = s_paging_fetch_table(pml4, 3, virt);
-    pmle_t *pml2 = s_paging_fetch_table(pml3, 2, virt);
-    pmle_t *pml1 = s_paging_fetch_table(pml2, 1, virt);
-}
-
-static pmle_t*
-s_paging_get_table(pmle_t *pt, size_t l, uintptr_t virt)
-{
-    if(pt == NULL) return NULL;
-    size_t pmli = s_paging_pmli(l, virt);
-    if(s_state_cache.pmli[l] == pmli && s_state_cache.pml[l] != NULL)
-        return s_state_cache.pml[l];
-
-    pmle_t entry = pt[pmli];
-    if(!entry.p) return NULL;
-    return (pmle_t*)(mem_phys_tolinear(entry.paddr << 12));
-}
-
-page_mapping_t
-mem_get_mapping_as(page_directory_t *pd, uintptr_t addr)
-{
-    spinlock_acquire(pd->lock);
-    page_mapping_t mapping = { 0 };
-    
-    pmle_t *pml4 = (pmle_t*)pd->virt;
-    if(s_state_cache.pd != pd) memset(&s_state_cache, 0, sizeof(s_state_cache));
-
-    pmle_t *pml3 = s_paging_get_table(pml4, 3, addr);
-    pmle_t *pml2 = s_paging_get_table(pml3, 2, addr);
-    pmle_t *pml1 = s_paging_get_table(pml2, 1, addr);
-    if(pml1 == NULL) goto release_return;
-
-    size_t pml1i = s_paging_pmli(0, addr);
-    pmle_t pml1e = pml1[pml1i];
-
-    mapping = (page_mapping_t) {
-        .phys = (pml1e.paddr << 12) & ~PAGE_MASK,
-        .pf = {
-            .present = pml1e.p,
-            .writeable = pml1e.rw,
-            .useraccess = pml1e.us,
-            .executable = !pml1e.xd
-        }
-    };
-release_return:
-    spinlock_release(pd->lock);
-    return mapping;
-}
-
-page_mapping_t mem_get_mapping(uintptr_t addr)
-{ return mem_get_mapping_as(current_page_directory, addr); }
-
-
-bool
-mem_check_ptr(const void *ptr)
-{
-    return mem_get_mapping((uintptr_t)ptr).pf.present != 0;
-}
-
-void
-mem_set_mapping_as(page_directory_t *pd, page_mapping_t mapping, uintptr_t virt)
-{
-    spinlock_acquire(pd->lock);
-    s_paging_cache_tables(pd, virt);
-    pmle_t *pml1 = s_state_cache.pml[0];
-    size_t pml1i = s_paging_pmli(0, virt);
-
-    pml1[pml1i] = (pmle_t) {
-        .p = mapping.pf.present,
-        .rw = mapping.pf.writeable,
-        .us = mapping.pf.useraccess,
-        .xd = !mapping.pf.executable,
-        .paddr = mapping.phys >> 12
-    };
-    spinlock_release(pd->lock);
-}
-
-void mem_set_mapping(page_mapping_t mapping, uintptr_t virt)
-{ mem_set_mapping_as(current_page_directory, mapping, virt); }
-
-void
-mem_ensure_range_as(page_directory_t *pd, uintptr_t from, uintptr_t to, page_flags_t flg)
-{
-    spinlock_acquire(pd->lock);
-    from &= ~(PAGE_SIZE - 1);
-
-    if(to < from) to = from;
-    size_t pages = (to - from) >> 12;
-    if(pages == 0) pages = 1;
-    for(size_t i = 0; i < pages; i++) {
-        uintptr_t waddr = from + (i << 12);
-        s_paging_cache_tables(pd, waddr);
-        pmle_t *pml1 = s_state_cache.pml[1];
-        size_t pml1i = s_paging_pmli(0, waddr);
-
-        if(!pml1[pml1i].p) {
-            physptr_t phys = mem_phys_alloc(1);
-            pml1[pml1i] = (pmle_t) {
-                .p = flg.present,
-                .rw = flg.writeable,
-                .us = flg.useraccess,
-                .xd = !flg.executable,
-                .paddr = phys >> 12
-            };
-        }
-    }
-    spinlock_release(pd->lock);
-}
-
-void mem_ensure_range(uintptr_t from, uintptr_t to, page_flags_t flg)
-{ mem_ensure_range_as(current_page_directory, from, to, flg); }
-
-struct Registers*
-s_pagefault_handler(struct Registers *state)
-{
-    extern uint64_t __isr_err;
-    
-    uintptr_t fault_addr = 0;
-    __asm__ volatile("movq %%cr2, %0": "=r"(fault_addr));
-
-    bool present = __isr_err & 1;
-    bool write = __isr_err & 2;
-    bool user = __isr_err & 4;
-    bool fetch = __isr_err & 16;
-
-    klogf("Page fault at %016X\n", fault_addr);
-    klogf("%s %s from a %s address\n", 
-            user ? "user" : "kernel",
-            write ? "wrote" : "read",
-            present ? "present" : "non-present");
-
-    kpanic("Unhandled page fault at %016X\n", state->ip);
-    return state;
-}
-
-void
-mem_paging_setup(void)
-{
-    memset(s_kernel_initial_pml4, 0, PAGE_SIZE);
-    memset(s_kernel_initial_pml3, 0, 2 * PAGE_SIZE);
-    memset(s_kernel_initial_pml2, 0, 2 * PAGE_SIZE);
-    memset(s_kernel_initial_pml1, 0, PAGE_SIZE);
-    s_kernel_initial_pd = (page_directory_t){
-        .phys = mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml4),
-        .virt = (union PageEntry*)&s_kernel_initial_pml4,
-        .ref = 1,
-        .id = s_next_pdid++
-    };
-    current_page_directory = &s_kernel_initial_pd;
-
-    /* Map first few GiBs */
-    s_kernel_initial_pml4[256] =
-        mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml3[0])
-        | 3;
-    s_kernel_initial_pml3[0][0] =
-        mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml2[0])
-        | 3;
-    for(int i = 0; i < 512; i++) {
-        s_kernel_initial_pml2[0][i] = (i * (PAGE_SIZE * 512)) | 0x80 | 3;
-    }
-
-    size_t kernel_pml4e = (boot_kernel_virtual_base >> (39));
-    size_t kernel_pml3e = (boot_kernel_virtual_base >> (30)) % 512;
-    size_t kernel_pml2e = (boot_kernel_virtual_base >> (21)) % 512;
-    size_t kernel_npages = ((((uintptr_t)&_kernel_end) - boot_kernel_virtual_base) >> 12) + 1;
-    klogf("Kernel has %i pages\n", kernel_npages);
-
-    /* Map kernel pages */
-    s_kernel_initial_pml4[511] =
-        mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml3[1]) | 3;
-    s_kernel_initial_pml3[1][kernel_pml3e] =
-        mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml2[1]) | 3;
-    s_kernel_initial_pml2[1][kernel_pml2e] =
-        mem_linear_tophys_koffset((uintptr_t)&s_kernel_initial_pml1[0]) | 3;
-    for(int i = 0; i < kernel_npages; i++) {
-        s_kernel_initial_pml1[0][i] = (i * PAGE_SIZE) + boot_kernel_physical_address | 3;
-    }
-    
-    int_set_handler(14, s_pagefault_handler);
-    __asm__ volatile("mov %0, %%cr3":: "r"(s_kernel_initial_pd.phys));
-}
diff --git a/arch/x86_64/processor.c b/arch/x86_64/processor.c
new file mode 100644
index 0000000..44d437a
--- /dev/null
+++ b/arch/x86_64/processor.c
@@ -0,0 +1,40 @@
+#include "arch/processor.h"
+#include "arch/cpu.h"
+#include "arch/x86_64/msr.h"
+
+processor_t s_processors[PROCESSOR_MAX];
+processor_t *proc_bsp = &s_processors[0];
+
+extern void x86_64_lgdt(struct XDTR *gdtr);
+extern void x86_64_flush_tss(void);
+extern void x86_64_lidt(struct XDTR *idtr);
+
+extern void gdt_setup(processor_t*);
+extern void tss_setup(processor_t*);
+extern void idt_setup(processor_t*);
+
+void 
+processor_setup(processor_t *proc)
+{
+    gdt_setup(proc);
+    tss_setup(proc);
+    idt_setup(proc);
+
+    x86_64_lgdt(&proc->_gdtr);
+    x86_64_lidt(&proc->_idtr);
+    x86_64_flush_tss();
+
+    msr_gsbase_write((uintptr_t)proc);
+}
+
+processor_t*
+processor_list(void)
+{
+    return s_processors;
+}
+
+processor_t*
+processor_current(void)
+{
+    return (processor_t*)msr_gsbase_read();
+}
diff --git a/arch/x86_64/restore.S b/arch/x86_64/restore.S
new file mode 100644
index 0000000..f4aa939
--- /dev/null
+++ b/arch/x86_64/restore.S
@@ -0,0 +1,20 @@
+.global _arch_context_restore
+.type _arch_context_restore @function
+_arch_context_restore:
+    movq %rdi, %rsp
+    popq %r15
+    popq %r14
+    popq %r13
+    popq %r12
+    popq %r11
+    popq %r10
+    popq %r9
+    popq %r8
+    popq %rbp
+    popq %rdi
+    popq %rsi
+    popq %rdx
+    popq %rcx
+    popq %rbx
+    popq %rax
+    retq
diff --git a/arch/x86_64/savestate.S b/arch/x86_64/savestate.S
deleted file mode 100644
index c89933b..0000000
--- a/arch/x86_64/savestate.S
+++ /dev/null
@@ -1,39 +0,0 @@
-.global saveregs
-.type saveregs @function
-saveregs:
-    pushq %rax
-    pushq %rbx
-    pushq %rcx
-    pushq %rdx
-    pushq %rsi
-    pushq %rdi
-    pushq %rbp
-    pushq %r8
-    pushq %r9
-    pushq %r10
-    pushq %r11
-    pushq %r12
-    pushq %r13
-    pushq %r14
-    pushq %r15
-    retq
-
-.global loadregs
-.type loadregs @function
-loadregs:
-    popq %r15
-    popq %r14
-    popq %r13
-    popq %r12
-    popq %r11
-    popq %r10
-    popq %r9
-    popq %r8
-    popq %rbp
-    popq %rdi
-    popq %rsi
-    popq %rdx
-    popq %rcx
-    popq %rbx
-    popq %rax
-
diff --git a/arch/x86_64/serial.c b/arch/x86_64/serial.c
deleted file mode 100644
index 1b49e3f..0000000
--- a/arch/x86_64/serial.c
+++ /dev/null
@@ -1,62 +0,0 @@
-#include "serial.h"
-#include "uart.h"
-#include "io/log.h"
-
-static struct LogDevice s_serial_logdev =
-    { .out = serial_out, .chain = NULL };
-
-bool serial_supported = true;
-
-void
-serial_setup(void)
-{
-    /* Disable interrupts. */
-    poutb(SERIAL_UART_COM_IER(SERIAL_UART_COM1), 0x0);
-    /* Enable DLAB. */
-    poutb(SERIAL_UART_COM_LCR(SERIAL_UART_COM1), 0x80);
-    /* Set divisor to 3 (38400 baud)*/
-    poutb(SERIAL_UART_COM_DLAB_DLL(SERIAL_UART_COM1), 3);
-    poutb(SERIAL_UART_COM_DLAB_DLH(SERIAL_UART_COM1), 0);
-    /* Set flags for LCR (8 bits, no parity, one stop)*/
-    poutb(SERIAL_UART_COM_LCR(SERIAL_UART_COM1), 1 | 2);
-    /* Enable & clear FIFO, 14-byte threshold */
-    poutb(SERIAL_UART_COM_FCR(SERIAL_UART_COM1), 1 | 2 | 4 | 0xC0);
-    /* Enable interrupts, set RTS/DSR. */
-    poutb(SERIAL_UART_COM_MCR(SERIAL_UART_COM1), 1 | 2 | 8);
-    /* Set loopback mode for testing. */
-    poutb(SERIAL_UART_COM_MCR(SERIAL_UART_COM1), 2 | 4 | 8 | 0x10);
-    /* Test serial output. */
-    poutb(SERIAL_UART_COM1, 0xAE);
-    if(pinb(SERIAL_UART_COM1) != 0xAE) {
-        serial_supported = false;
-        return;
-    }
-
-    /* Serial is not faulty.
-     * No loopback, enable output 1 & 2.*/
-    poutb(SERIAL_UART_COM_MCR(SERIAL_UART_COM1), 1 | 2 | 4 | 8);
-
-    klog_newdev(&s_serial_logdev);
-}
-
-static ALWAYS_INLINE bool
-serial_transmit_empty(uint16_t com)
-{
-    return pinb(SERIAL_UART_COM_LSR(com) & 0x20);
-}
-
-static inline void
-serial_outb(uint16_t com, uint8_t b)
-{
-    if(b == '\n') serial_outb(com, '\r');
-    while(!serial_transmit_empty(SERIAL_UART_COM1));
-    poutb(com, b);
-}
-
-void
-serial_out(const char *s, size_t len)
-{
-    if(!serial_supported) return;
-    for(; len > 0; len--)
-        serial_outb(SERIAL_UART_COM1, *(s++));
-}
diff --git a/arch/x86_64/serial.h b/arch/x86_64/serial.h
deleted file mode 100644
index ecb896d..0000000
--- a/arch/x86_64/serial.h
+++ /dev/null
@@ -1,27 +0,0 @@
-#ifndef JOVE_KERNEL_ARCH_x86_64_SERIAL_H
-#define JOVE_KERNEL_ARCH_x86_64_SERIAL_H 1
-
-#include <stdbool.h>
-#include <stddef.h>
-
-#define SERIAL_UART_COM1 0x3F8
-#define SERIAL_UART_COM2 0x2F8
-
-#define SERIAL_UART_COM_THR(COM)        COM
-#define SERIAL_UART_COM_RBR(COM)        COM
-#define SERIAL_UART_COM_DLAB_DLL(COM)   COM
-#define SERIAL_UART_COM_IER(COM)        (COM + 1)
-#define SERIAL_UART_COM_DLAB_DLH(COM)   (COM + 1)
-#define SERIAL_UART_COM_IIR(COM)        (COM + 2)
-#define SERIAL_UART_COM_FCR(COM)        (COM + 2)
-#define SERIAL_UART_COM_LCR(COM)        (COM + 3)
-#define SERIAL_UART_COM_MCR(COM)        (COM + 4)
-#define SERIAL_UART_COM_LSR(COM)        (COM + 5)
-#define SERIAL_UART_COM_MSR(COM)        (COM + 6)
-#define SERIAL_UART_COM_SR(COM)         (COM + 7)
-
-extern bool serial_supported;
-
-void serial_out(const char *s, size_t len);
-
-#endif
diff --git a/arch/x86_64/syscall.c b/arch/x86_64/syscall.c
deleted file mode 100644
index 0398f11..0000000
--- a/arch/x86_64/syscall.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "usr/umode.h"
diff --git a/arch/x86_64/syscall_entry.c b/arch/x86_64/syscall_entry.c
new file mode 100644
index 0000000..56dedce
--- /dev/null
+++ b/arch/x86_64/syscall_entry.c
@@ -0,0 +1,25 @@
+#include "arch/processor.h"
+#include "syscall/handler.h"
+
+__attribute__((naked))
+void _syscall_entry()
+{
+    __asm__ volatile(" \
+    pushq %%r11; \
+    pushq %%rcx; \
+    swapgs; \
+    movq %%gs:%c[tcb], %%rax; \
+    movq %%rsp, %c[sp](%%rax); \
+    movq %c[ksp](%%rax), %%rsp; \
+    pushq %c[sp](%%rax); \
+    callq _syscall_handler; \
+    swapgs; \
+    popq %%rsp; \
+    popq %%rcx; \
+    popq %%r11; \
+    sysretq; \
+    "
+    :: [tcb] "i"(offsetof(processor_t, tcb)),
+       [sp] "i"(offsetof(tcb_t, sp)),
+       [ksp] "i"(offsetof(tcb_t, ksp)));
+}
diff --git a/arch/x86_64/syscall_setup.S b/arch/x86_64/syscall_setup.S
deleted file mode 100644
index 4f5c6f0..0000000
--- a/arch/x86_64/syscall_setup.S
+++ /dev/null
@@ -1,41 +0,0 @@
-.extern _kernel_task_sp
-.extern syscall_handler
-
-.global syscall_entry
-.type syscall_entry @function
-syscall_entry:
-    swapgs
-    movq %rsp, %rax
-    movq _kernel_task_bp, %rsp
-    pushq %rax
-    pushq %rbp
-    pushq %rcx
-    pushq %r11
-    call syscall_handler
-    popq %r11
-    popq %rcx
-    popq %rbp
-    popq %rsp
-    swapgs
-    sysretq
-
-.global syscall_setup_syscall
-.type syscall_setup_syscall @function
-syscall_setup_syscall:
-    movq $0xc0000080, %rcx
-    rdmsr
-    or $1, %eax
-    wrmsr
-    
-    movq $0xc0000081, %rcx
-    rdmsr
-    mov  $0x001b0008, %edx
-    wrmsr
-
-    movq $0xc0000082, %rcx
-    leaq syscall_entry, %rdx
-    mov %edx, %eax
-    shr $32, %rdx
-    wrmsr
-
-    retq
diff --git a/arch/x86_64/tables.c b/arch/x86_64/tables.c
deleted file mode 100644
index f530089..0000000
--- a/arch/x86_64/tables.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#include "tables.h"
-
-void
-arch_tables_setup(void)
-{
-    x86_64_load_gdt();
-    x86_64_load_idt();
-}
diff --git a/arch/x86_64/tasking.c b/arch/x86_64/tasking.c
deleted file mode 100644
index 9b29330..0000000
--- a/arch/x86_64/tasking.c
+++ /dev/null
@@ -1,86 +0,0 @@
-#include "usr/tasking.h"
-#include "mem/memory.h"
-#include "io/log.h"
-#include "lib/hashtable.h"
-#include "lib/string.h"
-#include "paging.h"
-#include "cpu.h"
-#include "tss.h"
-
-struct TaskBody {
-    struct Task base;
-    struct Registers state;
-};
-
-struct Task *task_current;
-uintptr_t _kernel_task_bp = 0;
-
-//static struct SLinkedList s_tasks;
-static struct HashTable s_tasks;
-
-static struct SlabCache s_task_cache;
-static struct SlabCache s_kbp_cache;
-
-static tid_t s_task_id_next = 1;
-
-static size_t
-s_task_hash_func(const void* tid, size_t _)
-{
-    return (tid_t)tid;
-}
-
-void
-tasking_setup(void)
-{
-    hashtable_new(&s_tasks, struct TaskBody*, tid_t);
-    s_tasks.hash_function = s_task_hash_func;
- 
-    mem_slabcache_new(&s_task_cache, "tasks", sizeof(struct TaskBody));
-    mem_slabcache_new(&s_kbp_cache, "kernel stacks", 4096);
-
-    struct TaskBody *ktask = mem_slab_alloc(&s_task_cache);
-    *ktask = (struct TaskBody){
-        .base.id = s_task_id_next++,
-        .base.kbp = ((uintptr_t)mem_slab_alloc(&s_kbp_cache)) + 0xFF0,
-        .base.perm = (size_t)-1,
-        .base.pd = current_page_directory
-    };
-    hashtable_insert(&s_tasks, 0, ktask);
-
-    task_current = (struct Task*)ktask;
-    tss_set_rsp(0, task_current->kbp);
-    _kernel_task_bp = task_current->kbp;
-}
-
-struct Task*
-task_new(struct Task *parent)
-{
-    struct TaskBody *new = mem_slab_alloc(&s_task_cache);
-    memcpy(new, parent, sizeof(struct TaskBody));
-    new->base.id = s_task_id_next++;
-    
-    uintptr_t ksp_base = (uintptr_t)mem_slab_alloc(&s_kbp_cache);
-    new->base.kbp = ksp_base + 0xFFF;
-    new->base.perm = parent->perm;
-
-    hashtable_insert(&s_tasks, (void*)new->base.id, new);
-    return (struct Task*)new;
-}
-
-struct Task*
-task_get(tid_t id)
-{
-    struct Task **task = hashtable_get(&s_tasks, (void*)id, struct Task*);
-    if(task == NULL) return NULL;
-    return *task;
-}
-
-void
-task_free(struct Task *task)
-{
-    struct TaskBody *body = (struct TaskBody*)task;
-    task->pd->ref--;
-    task->kbp -= 0xFFF;
-    mem_slab_free(&s_kbp_cache, (void*)(task->kbp));
-    klogf("Need impl for task_free\n");
-}
diff --git a/arch/x86_64/tcb_prepare.c b/arch/x86_64/tcb_prepare.c
new file mode 100644
index 0000000..238d70d
--- /dev/null
+++ b/arch/x86_64/tcb_prepare.c
@@ -0,0 +1,9 @@
+#include "tasking.h"
+
+void 
+tcb_prepare(tcb_t *tcb, void *ip)
+{
+    uintptr_t state[15] = { 0 };
+    tcb_stack_push(tcb, &ip, sizeof(void*));
+    tcb_stack_push(tcb, state, sizeof(state));
+}
diff --git a/arch/x86_64/tcb_switch.c b/arch/x86_64/tcb_switch.c
new file mode 100644
index 0000000..bc8808d
--- /dev/null
+++ b/arch/x86_64/tcb_switch.c
@@ -0,0 +1,18 @@
+#include "tasking.h"
+#include "arch/processor.h"
+
+extern void _arch_context_restore(uintptr_t rsp);
+
+void
+tcb_switch(tcb_t *to)
+{
+    processor_t *proc = processor_current();
+    tcb_t *from = proc->tcb;
+
+    proc->tcb = to;
+    if(from != to) {
+        pd_switch(to->pd);
+    }
+    tss_set_rsp(&proc->_tss, 0, to->ksp);
+    _arch_context_restore(to->ksp);
+}
diff --git a/arch/x86_64/umode_enter.S b/arch/x86_64/umode_enter.S
deleted file mode 100644
index 29aa4e3..0000000
--- a/arch/x86_64/umode_enter.S
+++ /dev/null
@@ -1,8 +0,0 @@
-.global umode_enter
-.type umode_enter @function
-umode_enter:
-    movq %rdi, %rcx
-    movq %rsi, %rsp
-    movq $0x0202, %r11
-    cli
-    sysretq
diff --git a/arch/x86_64/umode_enter.c b/arch/x86_64/umode_enter.c
new file mode 100644
index 0000000..3c7fa18
--- /dev/null
+++ b/arch/x86_64/umode_enter.c
@@ -0,0 +1,17 @@
+#include "tasking.h"
+
+__attribute__((noreturn))
+void
+umode_enter(void *ip, void *sp)
+{
+    __asm__ volatile("mov %0, %%rsp; \
+                      push %%rcx; \
+                      mov %1, %%rcx; \
+                      mov $0x202, %%r11; \
+                      cli; \
+                      swapgs; \
+                      sysretq"::
+                      "r"(sp), "r"(ip):
+                      "memory");
+    for(;;);
+}
diff --git a/arch/x86_64/vm_tophys.c b/arch/x86_64/vm_tophys.c
new file mode 100644
index 0000000..2b16880
--- /dev/null
+++ b/arch/x86_64/vm_tophys.c
@@ -0,0 +1,23 @@
+#include "memory.h"
+#include "boot.h"
+
+uintptr_t
+pm_tovirt(physptr_t phys)
+{
+    if(phys < (1 * GiB))
+        return (uintptr_t)(phys + PHYSMAP_MEMORY_BASE);
+    kpanic("Missing impl for physical addresses > 1GiB (%#016X)\n",
+            phys);
+}
+
+physptr_t
+vm_tophys(uintptr_t virt)
+{
+    return vm_mapping_get(virt).phys;
+}
+
+physptr_t
+vm_tophys_koff(uintptr_t virt)
+{
+    return (virt - _kernel_virtual_base) + boot_kernel_physical_address;
+}
diff --git a/boot/cmdline.c b/boot/cmdline.c
index aa6aa05..5a68466 100644
--- a/boot/cmdline.c
+++ b/boot/cmdline.c
@@ -1,15 +1,18 @@
-#include "cmdline.h"
+#include "commandline.h"
+#include "klib/hash.h"
+#include "klib/rbtree.h"
+#include "string.h"
 #include "boot.h"
-#include "mem/memory.h"
-#include "lib/string.h"
-#include "io/log.h"
+#include "memory.h"
+#include "print.h"
 
-static struct HashTable s_cmdline_kernel;
+static rbtree_t s_cmdline_kernel;
 
 const char*
 cmdline_get(const char *key)
 {
-    const char** value = hashtable_get(&s_cmdline_kernel, key, const char*);
+    intmax_t hash = string_hash(key);
+    char** value = rbtree_find(&s_cmdline_kernel, hash);
     if(value == NULL) return NULL;
     return *value;
 }
@@ -17,7 +20,7 @@ cmdline_get(const char *key)
 void
 cmdline_kernel_setup(void)
 {
-    hashtable_news(&s_cmdline_kernel, const char*);
+    rbtree_new(&s_cmdline_kernel, char*);
     size_t cmdi = 0;
     
     const char *cmdline = boot_kernel_cmdline;
@@ -28,23 +31,23 @@ cmdline_kernel_setup(void)
         size_t keyi = cmdi;
         while(cmdline[keyi] != '=' && cmdline[keyi] != 0) keyi++;
         if(cmdline[keyi] == 0 || keyi == 0) {
-            klogf("kernel cmdline is empty or malformed; skipping.\n");
+            kwarnf("kernel cmdline is empty or malformed; skipping.\n");
             break;
         }
 
         size_t keylen = keyi - cmdi;
-        char *key = mem_alloc(keylen);
+        char *key = kmalloc(keylen);
         memcpy(key, &cmdline[cmdi], keylen);
 
         size_t valuei = keyi + 1;
         while(cmdline[valuei] != ' ' && cmdline[valuei] != 0) valuei++;
 
         size_t valuelen = (valuei - keyi) - 1;
-        char *value = mem_alloc(valuelen);
+        char *value = kmalloc(valuelen);
         if(valuelen != 0) memcpy(value, &cmdline[keyi + 1], valuelen);
 
-        klogf("%s = %s\n", key, value);
-        hashtable_insert(&s_cmdline_kernel, key, &value);
+        kdbgf("%s = %s\n", key, value);
+        rbtree_insert(&s_cmdline_kernel, string_hash(key), &value);
         cmdi = valuei + 1;
     }
 }
diff --git a/boot/cmdline.h b/boot/cmdline.h
deleted file mode 100644
index b1162b7..0000000
--- a/boot/cmdline.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef JOVE_BOOT_CMDLINE_H
-#define JOVE_BOOT_CMDLINE_H 1
-
-#include "lib/hashtable.h"
-
-const char *cmdline_get(const char *key);
-
-void cmdline_kernel_setup(void);
-
-#endif
diff --git a/boot/limine/limine.c b/boot/limine/limine.c
index 7cc50d0..14f85f5 100644
--- a/boot/limine/limine.c
+++ b/boot/limine/limine.c
@@ -1,5 +1,5 @@
 #include "limine.h"
-#include "boot/boot.h"
+#include "boot.h"
 
 static char s_kernel_stack[KERNEL_INITIAL_STACK_WIDTH];
 
diff --git a/compile_flags.txt b/compile_flags.txt
deleted file mode 100644
index 8a9f09e..0000000
--- a/compile_flags.txt
+++ /dev/null
@@ -1,4 +0,0 @@
--I.
--ffreestanding
--nostdlib
--lgcc
diff --git a/config.mk b/config.mk
index 11ce9f4..e2a9836 100644
--- a/config.mk
+++ b/config.mk
@@ -10,7 +10,8 @@ CFLAGS = \
 		  -fno-pie \
 		  -fno-pic \
 		  -g \
-		  -D$(TARGET_MACHINE) \
+		  -D__$(TARGET_MACHINE)__ \
+		  -Iinclude \
 		  -I.
 
 LDFLAGS = -nostdlib \
@@ -20,5 +21,5 @@ LDFLAGS = -nostdlib \
 ifeq "$(TARGET_MACHINE)" "x86_64"
 	CFLAGS += -mno-red-zone \
 			  -mcmodel=kernel \
-			  -MMD
+			  -mfsgsbase
 endif
diff --git a/device/processor.c b/device/processor.c
new file mode 100644
index 0000000..5c4b500
--- /dev/null
+++ b/device/processor.c
@@ -0,0 +1,4 @@
+#include "arch/processor.h"
+
+page_directory_t *pd_current(void) { return processor_current()->pd; }
+tcb_t *tcb_current(void) { return processor_current()->tcb; }
diff --git a/device/serial.c b/device/serial.c
new file mode 100644
index 0000000..5000e0e
--- /dev/null
+++ b/device/serial.c
@@ -0,0 +1,77 @@
+#include "device/serial.h"
+#include "device/uart.h"
+#include "jove.h"
+
+serial_dev_t COM1;
+
+serial_dev_t 
+serial_new(uint16_t com)
+{
+    serial_dev_t dev = { .com = com };
+    serial_set_int(&dev, false);
+    serial_set_baud(&dev, 3);
+    serial_set_lcr(&dev, 1 | 2);
+    serial_set_fcr(&dev, 1 | 2 | 4 | 0xC0);
+    serial_set_fcr(&dev, 1 | 2 | 8);
+    serial_set_mcr(&dev, 1 | 2 | 4 | 8);
+    return dev;
+}
+
+void
+serial_set_int(serial_dev_t *dev, bool enable)
+{
+    poutb(SERIAL_UART_COM_IER(dev->com), enable);
+}
+
+void
+serial_set_baud(serial_dev_t *dev, uint16_t baud)
+{
+    /* Enable DLAB. */
+    poutb(SERIAL_UART_COM_LCR(dev->com), SERIAL_UART_COM_LCR(dev->com) | 0x80);
+    /* Write low & high bits. */
+    poutb(SERIAL_UART_COM_DLAB_DLL(dev->com), baud & 0xFF);
+    poutb(SERIAL_UART_COM_DLAB_DLH(dev->com), (baud >> 8) & 0xFF);
+    /* Disable DLAB. */
+    poutb(SERIAL_UART_COM_LCR(dev->com), SERIAL_UART_COM_LCR(dev->com) & 0x7F);
+}
+
+void
+serial_set_fcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_FCR(dev->com), flg);
+}
+
+void
+serial_set_lcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_LCR(dev->com), flg);
+}
+
+void
+serial_set_mcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_MCR(dev->com), flg);
+}
+
+uint8_t
+serial_line_status(serial_dev_t *dev)
+{
+    return pinb(SERIAL_UART_COM_LSR(dev->com));
+}
+
+void
+serial_write(serial_dev_t *dev, const char *s, size_t len)
+{
+    for(; len > 0; len--) {
+        char c = *(s++);
+        while((serial_line_status(dev) & 0x20) == 0) {}
+        if(c == '\n') poutb(dev->com, '\r');
+        poutb(dev->com, c);
+    }
+}
+
+void
+serial_setup(void)
+{
+    COM1 = serial_new(SERIAL_UART_COM1);
+}
diff --git a/include/api/errno.h b/include/api/errno.h
new file mode 100644
index 0000000..51921d2
--- /dev/null
+++ b/include/api/errno.h
@@ -0,0 +1,9 @@
+#ifndef _JOVE_ERRNO_H
+#define _JOVE_ERRNO_H 1
+
+enum {
+    EFAIL = 1,
+    EACCESS
+};
+
+#endif
diff --git a/include/api/syscall.h b/include/api/syscall.h
new file mode 100644
index 0000000..eb4235d
--- /dev/null
+++ b/include/api/syscall.h
@@ -0,0 +1,39 @@
+#ifndef _JOVE_API_SYSCALL_H
+#define _JOVE_API_SYSCALL_H 1
+
+#include <stdint.h>
+#include <stddef.h>
+
+typedef intmax_t syscall_id_t;
+
+static int __syscall(void *data)
+{
+    intmax_t r;
+    __asm__ volatile(" \
+            movq %1, %%rdi; \
+            syscall; \
+            movq %%rax, %0"
+            : "=r"(r)
+            : "r"(data));
+    return r;
+}
+
+enum {
+    SC_DBG_LOGF = 0,
+    SC_EXIT
+};
+
+struct sc_dbg_log
+{
+    syscall_id_t id;
+    size_t w;
+    const char *s;
+};
+
+struct sc_exit
+{
+    syscall_id_t id;
+    int exit_code;
+};
+
+#endif
diff --git a/include/arch/cpu.h b/include/arch/cpu.h
new file mode 100644
index 0000000..fe89dc0
--- /dev/null
+++ b/include/arch/cpu.h
@@ -0,0 +1,14 @@
+#ifndef _JOVE_ARCH_CPU_H
+#define _JOVE_ARCH_CPU_H 1
+
+#ifdef __x86_64__
+#include "x86_64/cpu.h"
+#endif
+
+void cpu_setup(void);
+
+void cpu_set_syscall_entry(void *entry);
+
+void umode_enter(void *ip, void *sp);
+
+#endif
diff --git a/include/arch/elf.h b/include/arch/elf.h
new file mode 100644
index 0000000..1b8c3dc
--- /dev/null
+++ b/include/arch/elf.h
@@ -0,0 +1,12 @@
+#ifndef _JOVE_ARCH_ELF_H
+#define _JOVE_ARCH_ELF_H 1
+
+#ifdef __x86_64__
+#include "x86_64/elf.h"
+#endif
+
+#include <stddef.h>
+
+uintptr_t elf_load(const void *data, size_t len);
+
+#endif
diff --git a/include/arch/page.h b/include/arch/page.h
new file mode 100644
index 0000000..25c5294
--- /dev/null
+++ b/include/arch/page.h
@@ -0,0 +1,34 @@
+#ifndef _JOVE_ARCH_PAGE_H
+#define _JOVE_ARCH_PAGE_H 1
+
+#define PAGE_SHIFT (12)
+#define PAGE_SIZE (1 << PAGE_SHIFT)
+#define PAGE_MASK (PAGE_SIZE - 1)
+
+#ifdef __x86_64__
+#include "x86_64/page.h"
+#endif
+
+typedef struct page_mapping_flags
+{
+    char present : 1;
+    char writeable : 1;
+    char useraccess : 1;
+    char executable : 1;
+} page_flags_t;
+
+typedef struct page_mapping
+{
+    uintptr_t phys;
+    page_flags_t pf;
+} page_mapping_t;
+
+typedef intmax_t pdid_t;
+
+page_directory_t *pd_new(void);
+page_directory_t *pd_dup(page_directory_t *pd);
+page_directory_t *pd_get(pdid_t id);
+
+void pd_switch(page_directory_t *pd);
+
+#endif
diff --git a/include/arch/processor.h b/include/arch/processor.h
new file mode 100644
index 0000000..871e5c7
--- /dev/null
+++ b/include/arch/processor.h
@@ -0,0 +1,39 @@
+#ifndef _JOVE_ARCH_PROCESSOR_H
+#define _JOVE_ARCH_PROCESSOR_H 1
+
+#ifdef __x86_64__
+#include "x86_64/processor.h"
+#endif
+
+#include "memory.h"
+#include "tasking.h"
+#include "klib/spinlock.h"
+
+#define _EXRTAB_C (PAGE_SIZE / sizeof(uintptr_t))
+
+typedef struct processor
+{
+    ARCH_SPECIFIC_PROCESSOR_MEMBERS;
+    unsigned int id;
+    unsigned int isr_depth;
+    page_directory_t *pd;
+    tcb_t *tcb;
+
+    uintptr_t exrtab[_EXRTAB_C];
+    size_t ert_i;
+} processor_t;
+
+extern processor_t *proc_bsp;
+
+void processor_setup(processor_t *proc);
+
+processor_t *processor_list(void);
+
+processor_t *processor_current(void);
+page_directory_t *pd_current(void);
+tcb_t *tcb_current(void);
+
+void _exrtab_push(void *v);
+void *_exrtab_pop(void);
+
+#endif
diff --git a/include/arch/x86_64/cpu.h b/include/arch/x86_64/cpu.h
new file mode 100644
index 0000000..6e467c1
--- /dev/null
+++ b/include/arch/x86_64/cpu.h
@@ -0,0 +1,6 @@
+#ifndef _JOVE_x86_64_CPU_H
+#define _JOVE_x86_64_CPU_H 1
+
+void cpu_arch_enable_sce(void);
+
+#endif
diff --git a/include/arch/x86_64/elf.h b/include/arch/x86_64/elf.h
new file mode 100644
index 0000000..1aaf116
--- /dev/null
+++ b/include/arch/x86_64/elf.h
@@ -0,0 +1,93 @@
+#ifndef _JOVE_x86_64_ELF_H
+#define _JOVE_x86_64_ELF_H 1
+
+#include <stdint.h>
+
+#define EI_MAG0 0x7F
+#define EI_MAG1 'E'
+#define EI_MAG2 'L'
+#define EI_MAG3 'F'
+
+#define EI_CLASS_32 1
+#define EI_CLASS_64 2
+
+#define EI_DATA_LE 1
+#define EI_DATA_BE 2
+
+#define EI_VERSION_CURRENT 1
+
+#define ET_NONE 0
+#define ET_REL 1
+#define ET_EXEC 2
+#define ET_DYN 3
+
+typedef struct elf64_file_header
+{
+    union {
+        struct {
+            uint8_t ei_mag[4];
+            uint8_t ei_class;
+            uint8_t ei_data;
+            uint8_t ei_version;
+            uint8_t ei_osabi;
+            uint8_t ei_abiver;
+            uint8_t ei_pad[7];
+        };
+        uint8_t e_ident[16];
+    };
+    uint16_t e_type;
+    uint16_t e_machine;
+    uint32_t e_version;
+    uint64_t e_entry;
+    uint64_t e_phoff;
+    uint64_t e_shoff;
+    uint32_t e_flags;
+    uint16_t e_ehsize;
+    uint16_t e_phentsize;
+    uint16_t e_phnum;
+    uint16_t e_shentsize;
+    uint16_t e_shnum;
+    uint16_t e_shstrndx;
+} elf_header_t;
+
+#define PT_NULL 0
+#define PT_LOAD 1
+#define PT_DYNAMIC 2
+#define PT_INTERP 3
+#define PT_NOTE 4
+#define PT_SHLIB 5
+#define PT_PHDR 6
+#define PT_TLS 7
+
+#define PF_X 1
+#define PF_W 2
+#define PF_R 4
+
+typedef struct elf64_program_header
+{
+    uint32_t p_type;
+    uint32_t p_flags;
+    uint64_t p_offset;
+    uint64_t p_vaddr;
+    uint64_t p_paddr;
+    uint64_t p_filesz;
+    uint64_t p_memsz;
+    uint64_t p_align;
+} elf_phdr_t;
+
+#define SHT_NULL 0
+#define SHT_PROGBITS 1
+
+typedef struct elf64_section_header
+{
+    uint32_t sh_name;
+    uint32_t sh_type;
+    uint64_t sh_flags;
+    uint64_t sh_addr;
+    uint64_t sh_offset;
+    uint64_t sh_size;
+    uint64_t sh_addralign;
+    uint64_t sh_entsize;
+} elf_shdr_t;
+
+#endif
diff --git a/include/arch/x86_64/gdt.h b/include/arch/x86_64/gdt.h
new file mode 100644
index 0000000..c17c9eb
--- /dev/null
+++ b/include/arch/x86_64/gdt.h
@@ -0,0 +1,23 @@
+#ifndef _JOVE_x86_64_GDT_H
+#define _JOVE_x86_64_GDT_H 1
+
+#include "tables.h"
+
+enum
+{
+    GDT_SEGMENT_KERNEL_NULL = 0,
+    GDT_SEGMENT_KERNEL_CODE,
+    GDT_SEGMENT_KERNEL_DATA,
+
+    GDT_SEGMENT_USER_NULL,
+    GDT_SEGMENT_USER_DATA,
+    GDT_SEGMENT_USER_CODE,
+
+    GDT_SEGMENT_TSS_LOW,
+    GDT_SEGMENT_TSS_HIGH,
+
+    GDT_SEGMENT_COUNT
+};
+typedef segment_descriptor_t gdt_t[GDT_SEGMENT_COUNT];
+
+#endif
diff --git a/include/arch/x86_64/idt.h b/include/arch/x86_64/idt.h
new file mode 100644
index 0000000..7a5c468
--- /dev/null
+++ b/include/arch/x86_64/idt.h
@@ -0,0 +1,25 @@
+#ifndef _JOVE_x86_64_IDT_H
+#define _JOVE_x86_64_IDT_H 1
+
+#include "tables.h"
+
+typedef struct interrupt_state
+{
+    uint64_t r15, r14, r13, r12, r11, r10, r9, r8;
+    uint64_t bp, di, si, dx, cx, bx, ax;
+    uint64_t ip, cs, flags, sp, ss;
+} int_state_t;
+
+typedef interrupt_gate_t idt_t[48];
+
+typedef int_state_t *(*int_handler_t)(int_state_t *);
+
+void int_handler_set(uint8_t i, int_handler_t handler);
+int_handler_t int_handler_get(uint8_t i);
+
+void int_state_print(int_state_t *state);
+
+extern uint64_t __isr_err;
+extern uint64_t __isr_num;
+
+#endif
diff --git a/include/arch/x86_64/msr.h b/include/arch/x86_64/msr.h
new file mode 100644
index 0000000..c20f8fc
--- /dev/null
+++ b/include/arch/x86_64/msr.h
@@ -0,0 +1,56 @@
+#ifndef _JOVE_x86_64_MSR_H
+#define _JOVE_x86_64_MSR_H 1
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define MSR_EFER 0xC0000080
+#define MSR_STAR 0xC0000081
+#define MSR_LSTAR 0xC0000082
+#define MSR_SFMASK 0xC0000084
+
+#define MSR_FSBASE 0xC0000100
+#define MSR_GSBASE 0xC0000101
+#define MSR_KERNELGSBASE 0xC0000102
+
+typedef union msr_efer
+{
+    struct {
+        uint8_t sce : 1;
+        uint8_t resv : 7;
+        uint8_t lme : 1;
+        uint8_t unk0 : 1;
+        uint8_t lma : 1;
+        uint8_t nxe : 1;
+        uint8_t svme : 1;
+        uint8_t lmsle : 1;
+        uint8_t ffxsr : 1;
+        uint8_t tce : 1;
+    };
+    uint32_t v[2];
+} msr_efer_t;
+
+typedef union msr_star
+{
+    struct {
+        uint32_t eip;
+        uint16_t kcs;
+        uint16_t ucs;
+    };
+    uint32_t v[2];
+} msr_star_t;
+typedef uintptr_t msr_lstar_t;
+
+void msr_efer_write(msr_efer_t v);
+msr_efer_t msr_efer_read(void);
+
+void msr_star_write(msr_star_t v);
+msr_star_t msr_star_read(void);
+
+void msr_lstar_write(msr_lstar_t v);
+msr_lstar_t msr_lstar_read(void);
+
+void msr_gsbase_write(uintptr_t gsbase);
+uintptr_t msr_gsbase_read(void);
+
+#endif
diff --git a/include/arch/x86_64/page.h b/include/arch/x86_64/page.h
new file mode 100644
index 0000000..cbbf642
--- /dev/null
+++ b/include/arch/x86_64/page.h
@@ -0,0 +1,40 @@
+#ifndef _JOVE_x86_64_PAGE_H
+#define _JOVE_x86_64_PAGE_H 1
+
+#include <stdint.h>
+#include "klib/spinlock.h"
+#include "assert.h"
+
+typedef union page_mapping_level_entry
+{
+    struct {
+        uint8_t p : 1; /* Present */
+        uint8_t rw : 1; /* Read/write. 0 for RO.*/
+        uint8_t us : 1; /* User/supervisor. 0 for DPL3 forbid */
+        uint8_t pwt : 1;
+        uint8_t pcd : 1;
+        uint8_t a : 1; /* Accessed */
+        uint8_t d : 1; /* Dirty */
+        uint8_t ps_pat : 1;
+        uint8_t g : 1; /* Global */
+        uint8_t _r0 : 2;
+        uint8_t r : 1;
+        uint64_t paddr : 35;
+        uint8_t _r1;
+        uint8_t pk : 4;
+        uint8_t xd : 1;
+    }__attribute__((packed));
+    uint64_t value;
+} __attribute__((packed)) pmle_t;
+
+typedef struct page_directory
+{
+    spinlock_t lock;
+    intmax_t id;
+    uintptr_t phys;
+    pmle_t *pml;
+} page_directory_t;
+
+#define _kernel_virtual_base 0xFFFFFFFF80000000ULL
+
+#endif
diff --git a/include/arch/x86_64/processor.h b/include/arch/x86_64/processor.h
new file mode 100644
index 0000000..c208eb1
--- /dev/null
+++ b/include/arch/x86_64/processor.h
@@ -0,0 +1,17 @@
+#ifndef _JOVE_x86_64_PROCESSOR_H
+#define _JOVE_x86_64_PROCESSOR_H 1
+
+#include "tables.h"
+#include "gdt.h"
+#include "idt.h"
+#include "tss.h"
+
+#define PROCESSOR_MAX 8
+
+#define ARCH_SPECIFIC_PROCESSOR_MEMBERS \
+    __attribute__((aligned(0x1000))) gdt_t _gdt; \
+    struct TSS _tss; \
+    struct XDTR _gdtr; \
+    struct XDTR _idtr
+
+#endif
diff --git a/arch/x86_64/tables.h b/include/arch/x86_64/tables.h
index e160c66..e311192 100644
--- a/arch/x86_64/tables.h
+++ b/include/arch/x86_64/tables.h
@@ -1,5 +1,5 @@
-#ifndef JOVE_ARCH_X86_64_TABLES_H
-#define JOVE_ARCH_X86_64_TABLES_H 1
+#ifndef _JOVE_X86_64_TABLES_H
+#define _JOVE_X86_64_TABLES_H 1
 
 #include <stdint.h>
 
@@ -16,7 +16,7 @@
 #define S_SEGMENT_TYPE_INT_GATE 14
 #define S_SEGMENT_TYPE_TRAP_GATE 15
 
-struct SegmentDescriptor
+typedef struct segment_descriptor
 {
     uint16_t limit_0_15;    /* Segment limit. */
     uint16_t base_0_15;     /* Segment base. */
@@ -24,16 +24,16 @@ struct SegmentDescriptor
     uint8_t type : 4;       /* Segment type. */
     uint8_t s : 1;          /* Descriptor type (0 = system, 1 = code/data)*/
     uint8_t dpl : 2;        /* Descriptor privilege level. */
-    uint8_t p : 1; ;        /* Present. */
+    uint8_t p : 1;          /* Present. */
     uint8_t limit_16_19 : 4;
     uint8_t avl : 1;        /* Available for use by system software. */
     uint8_t l : 1;          /* 64-bit segment (Ext). */
     uint8_t d_b : 1;        /* Default operation size (0 = 16-bit, 1 = 32-bit)*/
     uint8_t g : 1;          /* Granularity. */
     uint8_t base_24_31;
-}__attribute__((packed));
+}__attribute__((packed)) segment_descriptor_t;
 
-struct InterruptTrapGate
+typedef struct interrupt_gate
 {
     uint16_t base_0_15;
     uint16_t segment_selector;
@@ -46,7 +46,7 @@ struct InterruptTrapGate
     uint16_t base_16_31;
     uint32_t base_32_63;
     uint32_t resv;
-}__attribute__((packed));
+}__attribute__((packed)) interrupt_gate_t;
 
 struct XDTR /* Generic table descriptor struct */
 {
@@ -54,7 +54,4 @@ struct XDTR /* Generic table descriptor struct */
     uint64_t address;
 }__attribute__((packed));
 
-void x86_64_load_gdt(void);
-void x86_64_load_idt(void);
-
 #endif
diff --git a/arch/x86_64/tss.h b/include/arch/x86_64/tss.h
index dcdd01c..3184df5 100644
--- a/arch/x86_64/tss.h
+++ b/include/arch/x86_64/tss.h
@@ -15,6 +15,6 @@ struct TSS
     uint16_t iobp;
 };
 
-void tss_set_rsp(uint8_t dpl, uintptr_t rsp);
+void tss_set_rsp(struct TSS *tss, uint8_t dpl, uintptr_t rsp);
 
 #endif
diff --git a/include/assert.h b/include/assert.h
new file mode 100644
index 0000000..f208235
--- /dev/null
+++ b/include/assert.h
@@ -0,0 +1,10 @@
+#ifndef JOVE_LIB_ASSERT_H
+#define JOVE_LIB_ASSERT_H 1
+
+#include "jove.h"
+
+#define assert(cond) \
+    if(!(cond)) \
+        kpanic("Assert failure : %s\n", #cond)
+
+#endif
diff --git a/boot/boot.h b/include/boot.h
index cfdfa68..c4aa541 100644
--- a/boot/boot.h
+++ b/include/boot.h
@@ -35,6 +35,4 @@ extern struct MemoryMap boot_memorymap;
 extern struct BootModule boot_modules[BOOT_MODULE_MAX_ENTRIES];
 extern size_t boot_module_count;
 
-#define boot_kernel_virtual_base 0xFFFFFFFF80000000ULL
-
 #endif
diff --git a/include/commandline.h b/include/commandline.h
new file mode 100644
index 0000000..5c66cd3
--- /dev/null
+++ b/include/commandline.h
@@ -0,0 +1,8 @@
+#ifndef _JOVE_COMMANDLINE_H
+#define _JOVE_COMMANDLINE_H 1
+
+const char *cmdline_get(const char *key);
+
+void cmdline_kernel_setup(void);
+
+#endif
diff --git a/include/device/serial.h b/include/device/serial.h
new file mode 100644
index 0000000..d59b00f
--- /dev/null
+++ b/include/device/serial.h
@@ -0,0 +1,48 @@
+#ifndef _JOVE_DEVICE_SERIAL_H
+#define _JOVE_DEVICE_SERIAL_H 1
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+#include "klib/spinlock.h"
+
+#define SERIAL_UART_COM1 0x3F8
+#define SERIAL_UART_COM2 0x2F8
+
+#define SERIAL_UART_COM_THR(COM)        COM
+#define SERIAL_UART_COM_RBR(COM)        COM
+#define SERIAL_UART_COM_DLAB_DLL(COM)   COM
+#define SERIAL_UART_COM_IER(COM)        (COM + 1)
+#define SERIAL_UART_COM_DLAB_DLH(COM)   (COM + 1)
+#define SERIAL_UART_COM_IIR(COM)        (COM + 2)
+#define SERIAL_UART_COM_FCR(COM)        (COM + 2)
+#define SERIAL_UART_COM_LCR(COM)        (COM + 3)
+#define SERIAL_UART_COM_MCR(COM)        (COM + 4)
+#define SERIAL_UART_COM_LSR(COM)        (COM + 5)
+#define SERIAL_UART_COM_MSR(COM)        (COM + 6)
+#define SERIAL_UART_COM_SR(COM)         (COM + 7)
+
+typedef struct serial_device
+{
+    uint16_t com;
+    spinlock_t lock;
+} serial_dev_t;
+
+extern serial_dev_t COM1;
+
+void serial_setup(void);
+serial_dev_t serial_new(uint16_t com);
+
+void serial_set_int(serial_dev_t *dev, bool enable);
+void serial_set_baud(serial_dev_t *dev, uint16_t baud);
+
+void serial_set_fcr(serial_dev_t *dev, uint16_t flg);
+void serial_set_lcr(serial_dev_t *dev, uint16_t flg);
+void serial_set_mcr(serial_dev_t *dev, uint16_t flg);
+void serial_set_lsr(serial_dev_t *dev, uint16_t flg);
+void serial_set_msr(serial_dev_t *dev, uint16_t flg);
+
+uint8_t serial_line_status(serial_dev_t *dev);
+void serial_write(serial_dev_t *dev, const char *s, size_t len);
+
+#endif
diff --git a/arch/x86_64/uart.h b/include/device/uart.h
index 8386eb7..1724eb5 100644
--- a/arch/x86_64/uart.h
+++ b/include/device/uart.h
@@ -1,7 +1,7 @@
 #ifndef JOVE_KERNEL_ARCH_x86_64_UART_H
 #define JOVE_KERNEL_ARCH_x86_64_UART_H 1
 
-#include "lib/jove.h"
+#include "jove.h"
 #include <stdint.h>
 
 ALWAYS_INLINE uint8_t pinb(uint16_t port)
diff --git a/include/initrd.h b/include/initrd.h
new file mode 100644
index 0000000..7e7fe1e
--- /dev/null
+++ b/include/initrd.h
@@ -0,0 +1,17 @@
+#ifndef _JOVE_INITRD_H
+#define _JOVE_INITRD_H 1
+
+#include <stddef.h>
+
+typedef struct initrd_file {
+    void *header;
+    const char *name;
+    const void *data;
+    size_t size;
+} initrd_file_t;
+
+void initrd_setup(void);
+
+initrd_file_t *ird_getfile(const char *path);
+
+#endif
diff --git a/lib/jove.h b/include/jove.h
index 6015112..2330492 100644
--- a/lib/jove.h
+++ b/include/jove.h
@@ -4,8 +4,6 @@
 #define ALWAYS_INLINE inline __attribute__((always_inline))
 #define PAGEALIGN __attribute__((aligned(0x1000)))
 
-#define LOG2(n) (31 - __builtin_clz(n))
-
 extern void *_kernel_start;
 extern void *_kernel_end;
 
diff --git a/include/memory.h b/include/memory.h
new file mode 100644
index 0000000..35198e6
--- /dev/null
+++ b/include/memory.h
@@ -0,0 +1,49 @@
+#ifndef _JOVE_MEMORY_H
+#define _JOVE_MEMORY_H 1
+
+#define KiB 1024ULL
+#define MiB (KiB * KiB)
+#define GiB (MiB * KiB)
+#define TiB (GiB * KiB)
+
+#include <stdbool.h>
+#include <stddef.h>
+#include "arch/page.h"
+
+typedef uintptr_t physptr_t;
+
+extern const uintptr_t USERLAND_MEMORY_BASE;
+extern const uintptr_t USERLAND_MEMORY_LIMIT;
+extern const uintptr_t PHYSMAP_MEMORY_BASE;
+extern const uintptr_t PHYSMAP_MEMORY_LIMIT;
+extern const uintptr_t KERNEL_MEMORY_BASE;
+extern const uintptr_t KERNEL_MEMORY_LIMIT;
+
+page_mapping_t vm_pd_mapping_get(page_directory_t *pd, uintptr_t addr);
+void vm_pd_mapping_set(page_directory_t *pd, page_mapping_t mapping, uintptr_t addr);
+void vm_pd_ensure(page_directory_t *pd, uintptr_t from, uintptr_t to, page_flags_t flg);
+
+page_mapping_t vm_mapping_get(uintptr_t addr);
+void vm_mapping_set(page_mapping_t mapping, uintptr_t virt);
+void vm_ensure(uintptr_t from, uintptr_t to, page_flags_t flg);
+
+physptr_t vm_tophys(uintptr_t virt);
+physptr_t vm_tophys_koff(uintptr_t virt);
+
+uintptr_t pm_tovirt(physptr_t phys);
+
+physptr_t pm_alloc(size_t pages);
+void pm_reserve(physptr_t start, physptr_t end);
+void pm_release(physptr_t start, physptr_t end);
+
+void mm_setup_early(void);
+void vm_setup_early(void);
+
+void mm_setup(void);
+void vm_setup(void);
+
+void* kmalloc(size_t width);
+void *krealloc(void *ptr, size_t width);
+void kfree(void *ptr);
+
+#endif
diff --git a/include/print.h b/include/print.h
new file mode 100644
index 0000000..38a1dbc
--- /dev/null
+++ b/include/print.h
@@ -0,0 +1,25 @@
+#ifndef _JOVE_PRINT_H
+#define _JOVE_PRINT_H 1
+
+#include <stdarg.h>
+
+enum {
+    PRINT_DEBUG = 0,
+    PRINT_LOG,
+    PRINT_WARN,
+    PRINT_ERROR
+};
+
+#define PRINT_BUFFERW 512
+
+void prawf(const char *fmt, ...);
+
+void _plogvf(const char *file, const char *func, int line, int lvl, const char *fmt, va_list ap);
+void _plogf(const char *file, const char *func, int line, int lvl, const char *fmt, ...);
+
+#define kdbgf(...) _plogf(__FILE__, __FUNCTION__, __LINE__, PRINT_DEBUG, __VA_ARGS__)
+#define klogf(...) _plogf(__FILE__, __FUNCTION__, __LINE__, PRINT_LOG  , __VA_ARGS__)
+#define kwarnf(...) _plogf(__FILE__, __FUNCTION__, __LINE__, PRINT_WARN, __VA_ARGS__)
+#define kerrf(...) _plogf(__FILE__, __FUNCTION__, __LINE__, PRINT_ERROR, __VA_ARGS__)
+
+#endif
diff --git a/include/slab.h b/include/slab.h
new file mode 100644
index 0000000..04d42e4
--- /dev/null
+++ b/include/slab.h
@@ -0,0 +1,44 @@
+#ifndef JOVE_MEMORY_SLAB_H
+#define JOVE_MEMORY_SLAB_H 1
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#define SLABCACHE_NAME_LIMIT 32
+typedef struct slab_cache
+{
+    char name[SLABCACHE_NAME_LIMIT];
+
+    struct slab *list_free;
+    struct slab *list_partial;
+    struct slab *list_full;
+
+    size_t obj_count;
+    size_t obj_size;
+    size_t obj_capacity;
+
+    size_t slab_pages;
+} slab_cache_t;
+
+typedef struct slab
+{
+    struct slab *prev;
+    struct slab *next;
+    void *slab_base;
+    void *obj_base;
+
+    size_t free_count;
+    int free_index;
+    uintptr_t free[];
+} slab_t;
+
+void slabcache_new(slab_cache_t *cache, char *name, size_t objsize);
+
+void* slab_alloc(slab_cache_t *cache);
+void slab_free(slab_cache_t *cache, void *ptr);
+
+void* slab_get(slab_cache_t *cache, size_t index);
+void slab_set(slab_cache_t *cache, size_t index, void *data);
+
+#endif
diff --git a/lib/string.h b/include/string.h
index a91ec94..a91ec94 100644
--- a/lib/string.h
+++ b/include/string.h
diff --git a/include/tasking.h b/include/tasking.h
new file mode 100644
index 0000000..04118a9
--- /dev/null
+++ b/include/tasking.h
@@ -0,0 +1,44 @@
+#ifndef _JOVE_TASKING_H
+#define _JOVE_TASKING_H 1
+
+#include "arch/page.h"
+#include <stddef.h>
+#include <stdbool.h>
+
+#define KERNEL_STACKW 4096
+
+typedef intmax_t tcbid_t;
+
+typedef enum
+{
+    TCB_RUNNING,
+    TCB_PAUSED,
+    TCB_DEAD
+} tcb_state_t;
+
+typedef struct task_control_block
+{
+    tcbid_t id;
+    void *stack;
+    uintptr_t sp, ksp;
+    page_directory_t *pd;
+    tcb_state_t state;
+
+    int exit_code;
+} tcb_t;
+
+void tasking_setup(void);
+
+tcb_t *tcb_new(void *ip, page_directory_t *pd);
+void tcb_prepare(tcb_t *tcb, void *ip);
+void tcb_kill(tcb_t *tcb, int code);
+
+void tcb_switch(tcb_t *to);
+
+void tcb_stack_push(tcb_t *tcb, void *data, size_t len);
+
+void kexec(void *ip, int kargc, char **kargv, int kenvc, char **kenvp);
+
+void *umode_stack_new(void);
+
+#endif
diff --git a/include/umode_vma.h b/include/umode_vma.h
new file mode 100644
index 0000000..23619be
--- /dev/null
+++ b/include/umode_vma.h
@@ -0,0 +1,10 @@
+#ifndef _JOVE_UMODE_VMA_H
+#define _JOVE_UMODE_VMA_H 1
+
+#include <stdbool.h>
+#include <stddef.h>
+
+int user_vma_read(void *dest, const void *src, size_t w);
+int user_vma_write(void *dest, const void *src, size_t w);
+
+#endif
diff --git a/include/zone.h b/include/zone.h
new file mode 100644
index 0000000..002d1fc
--- /dev/null
+++ b/include/zone.h
@@ -0,0 +1,38 @@
+#ifndef JOVE_MEM_ZONE_H
+#define JOVE_MEM_ZONE_H 1
+
+#include <stdint.h>
+#include "klib/buddymap.h"
+
+enum {
+    MEM_ZONE_STANDARD = 0, /* First GiB of physical memory. */
+    MEM_ZONE_HIGHER,
+    MEM_ZONE_COUNT
+};
+
+#define MEM_ZONE_STANDARD_BASE 0
+#define MEM_ZONE_STANDARD_LIMIT (1 * GiB)
+#define MEM_ZONE_HIGHER_BASE MEM_ZONE_STANDARD_LIMIT
+
+#define MEM_BUDDY_ORDERS 12
+struct PhysicalMemoryZone
+{
+    const char *name;
+
+    uintptr_t base;
+    uintptr_t limit;
+
+    struct BuddyMap freemap;
+};
+
+int pm_zone_for(uintptr_t addr);
+uintptr_t pm_zone_bound_lower(size_t zone);
+uintptr_t pm_zone_bound_upper(size_t zone);
+size_t pm_zone_pages_free(size_t zone);
+int pm_zone_resv(size_t zone, uintptr_t base, uintptr_t limit);
+int pm_zone_free(size_t zone, uintptr_t base, uintptr_t limit);
+uintptr_t pm_zone_alloc(size_t zone, size_t pages);
+
+void pm_zone_setup(void);
+
+#endif
diff --git a/ird/initrd.c b/initrd/initrd.c
index f219243..8fe0f01 100644
--- a/ird/initrd.c
+++ b/initrd/initrd.c
@@ -1,12 +1,14 @@
 #include "initrd.h"
-#include "lib/string.h"
-#include "io/log.h"
-#include "boot/boot.h"
-#include "boot/cmdline.h"
-#include "mem/memory.h"
+#include "tar.h"
+#include "string.h"
+#include "commandline.h"
+#include "memory.h"
+#include "print.h"
+#include "klib/rbtree.h"
+#include "klib/hash.h"
+#include "boot.h"
 
-struct SlabCache s_initrd_cache;
-struct SLinkedList s_initrd_files;
+static rbtree_t s_initrd_files;
 
 static size_t
 s_tar_oct_dec(const char *oct)
@@ -23,40 +25,35 @@ s_tar_oct_dec(const char *oct)
 static void
 s_initrd_parse(struct BootModule *module)
 {
-    struct TARSector *sector = (struct TARSector*)module->addr;
+    struct tar_block *sector = (struct tar_block*)module->addr;
     while(true) {
-        struct TARHeader *header = (struct TARHeader*)sector;
+        tar_header_t *header = (tar_header_t*)sector;
         if(header->name[0] == 0) break;
 
-        struct InitrdFile *file = mem_slab_alloc(&s_initrd_cache);
-        *file = (struct InitrdFile){ 
+        initrd_file_t file_tmp;
+        initrd_file_t *file = rbtree_insert(
+                &s_initrd_files, 
+                string_hash(header->name), 
+                &file_tmp);
+
+        *file = (initrd_file_t){ 
             .header = header,
             .name = header->name,
             .size = s_tar_oct_dec(header->size),
             .data = &sector[1]
         };
-        klogf("File %s size %i\n", file->name, file->size);
-        sll_push(&s_initrd_files, file);
+        kdbgf("File %s size %i\n", file->name, file->size);
  
         sector = &sector[(file->size / 512) + 1];
         if(file->size % 512 > 0) sector = &sector[1];
     }
 }
 
-struct InitrdFile *
+initrd_file_t *
 ird_getfile(const char *path)
 {
-    for(struct SLLNode *node = s_initrd_files.head; node != NULL; node = node->next) {
-        struct InitrdFile *file = (struct InitrdFile*)node;
-        if(strcmp(file->name, path) == 0) return file;
-    }
-    return NULL;
-}
-
-struct SLinkedList *
-ird_getfiles(void)
-{
-    return &s_initrd_files;
+    initrd_file_t *file = rbtree_find(&s_initrd_files, string_hash(path));
+    return file;
 }
 
 void
@@ -64,10 +61,10 @@ initrd_setup(void)
 {
     const char *initrd_path = cmdline_get("initrd");
     if(initrd_path == 0) {
-        klogf("No initrd loaded!\n");
+        kerrf("No initrd loaded!\n");
         return;
     }
-    klogf("Initrd located in module path %s\n", initrd_path);
+    kdbgf("Initrd located in module path %s\n", initrd_path);
     struct BootModule *initrd_module = NULL;
     for(size_t i = 0; i < boot_module_count; i++) {
         struct BootModule *module = &boot_modules[i];
@@ -82,7 +79,6 @@ initrd_setup(void)
         return;
     }
 
-    sll_new(&s_initrd_files, sizeof(struct InitrdFile));
-    mem_slabcache_new(&s_initrd_cache, "initrd files", sizeof(struct InitrdFile));
+    rbtree_new(&s_initrd_files, initrd_file_t);
     s_initrd_parse(initrd_module);
 }
diff --git a/ird/tar.h b/initrd/tar.h
index 5c72620..5325a51 100644
--- a/ird/tar.h
+++ b/initrd/tar.h
@@ -1,9 +1,9 @@
 #ifndef JOVE_INITRD_TAR_H
 #define JOVE_INITRD_TAR_H 1
 
-struct TARSector { char data[512]; };
+struct tar_block { char data[512]; };
 
-struct TARHeader {
+typedef struct tar_header {
     char name[100];
     char mode[8];
     char owner[8];
@@ -13,6 +13,6 @@ struct TARHeader {
     char checksum[8];
     char link;
     char linkname[100];
-};
+} tar_header_t;
 
 #endif
diff --git a/io/interrupt.h b/io/interrupt.h
deleted file mode 100644
index 444ff01..0000000
--- a/io/interrupt.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef JOVE_IO_INTERRUPT_H
-#define JOVE_IO_INTERRUPT_H 1
-
-
-
-#endif
diff --git a/io/log.c b/io/log.c
deleted file mode 100644
index 14397a7..0000000
--- a/io/log.c
+++ /dev/null
@@ -1,68 +0,0 @@
-#include "log.h"
-#include "lib/jove.h"
-#include "lib/string.h"
-#include "lib/format.h"
-
-static struct LogDevice *s_first_logdev = NULL;
-
-void
-klog_newdev(struct LogDevice *dev)
-{
-    if(s_first_logdev == NULL) {
-        s_first_logdev = dev;
-    }else{
-        dev->chain = s_first_logdev;
-        s_first_logdev = dev;
-    }
-}
-
-static void
-s_klogc(struct LogDevice *dev, char c)
-{
-    dev->out(&c, 1);
-    if(dev->chain != NULL)
-        s_klogc(dev->chain, c);
-}
-
-void
-klogc(char c)
-{
-    s_klogc(s_first_logdev, c);
-}
-
-static void
-s_klogs(struct LogDevice *dev, const char *s, size_t slen)
-{
-    dev->out(s, slen);
-    if(dev->chain != NULL)
-        s_klogs(dev->chain, s, slen);
-}
-
-void
-klogs(const char *s)
-{
-    size_t slen = strlen(s);
-    s_klogs(s_first_logdev, s, slen);
-}
-
-void
-klogsn(const char *s, size_t len)
-{
-    s_klogs(s_first_logdev, s, len);
-}
-
-void
-kvlogf(const char *fmt, va_list ap)
-{
-    char buffer[256];
-    svfmt(buffer, 256, fmt, ap);
-    klogs(buffer);
-}
-
-void klogf(const char *fmt, ...)
-{
-    va_list ap;
-    va_start(ap, fmt);
-    kvlogf(fmt, ap);
-    va_end(ap);
-}
diff --git a/io/log.h b/io/log.h
deleted file mode 100644
index ad1526d..0000000
--- a/io/log.h
+++ /dev/null
@@ -1,22 +0,0 @@
-#ifndef JOVE_IO_LOG_H
-#define JOVE_IO_LOG_H 1
-
-#include <stddef.h>
-
-struct LogDevice
-{
-    void (*out)(const char*, size_t);
-    struct LogDevice *chain;
-};
-
-void klog_newdev(struct LogDevice *dev);
-
-void klogc(char c);
-void klogs(const char *s);
-void klogsn(const char *s, size_t len);
-
-#include <stdarg.h>
-void kvlogf(const char *fmt, va_list ap);
-void klogf(const char *fmt, ...);
-
-#endif
diff --git a/ird/initrd.h b/ird/initrd.h
deleted file mode 100644
index f236fa1..0000000
--- a/ird/initrd.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#ifndef JOVE_INITRD_H
-#define JOVE_INITRD_H 1
-
-#include <stddef.h>
-#include "tar.h"
-#include "lib/linkedlist.h"
-
-struct InitrdFile {
-    struct InitrdFile *next;
-    struct TARHeader *header;
-    const char *name;
-    size_t size;
-    const void *data;
-};
-
-void initrd_setup(void);
-
-struct InitrdFile *ird_getfile(const char *path);
-struct SLinkedList *ird_getfiles(void);
-
-#endif
diff --git a/lib/buddymap.c b/klib/buddymap.c
index 6a616c9..62cecf1 100644
--- a/lib/buddymap.c
+++ b/klib/buddymap.c
@@ -1,8 +1,10 @@
 #include "buddymap.h"
 #include "jove.h"
+#include "print.h"
 
 #define BLOCK_AT_LAYER(blocks, l, i) blocks[l][i / BUDDY_BLOCK_BITS]
 #define BLOCK_BITMASK(i) (1ULL << (i % BUDDY_BLOCK_BITS))
+#define LOG2(v) (31 - __builtin_clz(v))
 
 bool
 buddy_bit_test(struct BuddyMap *map, size_t l, size_t i)
diff --git a/lib/buddymap.h b/klib/buddymap.h
index 1af8dfb..1af8dfb 100644
--- a/lib/buddymap.h
+++ b/klib/buddymap.h
diff --git a/lib/format.h b/klib/format.h
index 5a2b75c..5a2b75c 100644
--- a/lib/format.h
+++ b/klib/format.h
diff --git a/klib/hash.h b/klib/hash.h
new file mode 100644
index 0000000..03b0f3a
--- /dev/null
+++ b/klib/hash.h
@@ -0,0 +1,18 @@
+#ifndef JOVE_LIB_HASH_H
+#define JOVE_LIB_HASH_H 1
+
+#include <stdint.h>
+
+static intmax_t
+string_hash(const char *str)
+{
+    /* Hash function courtesy of the following website:
+     * http://www.cse.yorku.ca/~oz/hash.html*/
+    intmax_t r = 5381;
+    while (*str) {
+        r = (r * 33) ^ *(str++);
+    }
+    return r;
+}
+
+#endif
diff --git a/lib/kpanic.c b/klib/kpanic.c
index 97e42eb..2918711 100644
--- a/lib/kpanic.c
+++ b/klib/kpanic.c
@@ -1,7 +1,8 @@
 #include "jove.h"
-#include "io/log.h"
+#include "print.h"
 
 #include <stdarg.h>
+#include <stddef.h>
 
 __attribute__((noreturn))
 void _kpanic(const char *file, int line, const char *fmt, ...)
@@ -9,7 +10,7 @@ void _kpanic(const char *file, int line, const char *fmt, ...)
     va_list ap;
     va_start(ap, fmt);
     klogf("!!! PANIC !!!\n%s:%i\n", file, line);
-    kvlogf(fmt, ap);
+    _plogvf(NULL, NULL, 0, PRINT_LOG, fmt, ap);
     va_end(ap);
     for(;;) __asm__ volatile("hlt");
 }
diff --git a/lib/linkedlist.c b/klib/linkedlist.c
index 6cc6403..6cc6403 100644
--- a/lib/linkedlist.c
+++ b/klib/linkedlist.c
diff --git a/lib/linkedlist.h b/klib/linkedlist.h
index 26c148e..26c148e 100644
--- a/lib/linkedlist.h
+++ b/klib/linkedlist.h
diff --git a/lib/ltostr.c b/klib/ltostr.c
index e28be31..e28be31 100644
--- a/lib/ltostr.c
+++ b/klib/ltostr.c
diff --git a/lib/mem.c b/klib/mem.c
index b60fbbd..cf9e2aa 100644
--- a/lib/mem.c
+++ b/klib/mem.c
@@ -1,5 +1,5 @@
 #include "string.h"
-#include "mem/memory.h"
+#include "memory.h"
 
 void*
 memset(void *dest, int c, size_t n)
@@ -46,7 +46,7 @@ char*
 strdup(const char *s)
 {
     size_t slen = strlen(s);
-    char *ret = mem_alloc(slen);
+    char *ret = kmalloc(slen);
     memcpy(ret, s, slen);
     return ret;
 }
diff --git a/klib/rbtree.c b/klib/rbtree.c
new file mode 100644
index 0000000..2920384
--- /dev/null
+++ b/klib/rbtree.c
@@ -0,0 +1,361 @@
+#include "rbtree.h"
+#include "assert.h"
+#include "string.h"
+
+#define BLACK 0
+#define RED 1
+
+#define LEFT 0
+#define left children[LEFT]
+
+#define RIGHT 1
+#define right children[RIGHT]
+
+#define CHILD_DIR(c) (c->parent->children[LEFT] == c ? LEFT : RIGHT)
+
+/**Given a root and a direction, rotate the subtree such that the order of the
+ * elements are unchanged.
+ * The opposite direction child of the given root is treated as the pivot point
+ * The dir-most child of the pivot becomes the opposite dir child of the root.
+ * The pivot becomes the root and vice-versa.
+ * @param tree to do rotation on.
+ * @param root of rotation.
+ * @param dir to rotate by.
+ * @return new root node.*/
+rbnode_t*
+s_node_rotate(rbtree_t *tree, rbnode_t *root, bool dir)
+{
+    assert(root != NULL);
+    rbnode_t *gparent = root->parent;
+    rbnode_t *sibling = root->children[1-dir];
+    rbnode_t *child = NULL;
+
+    assert(sibling != NULL);
+    child = sibling->children[dir];
+
+    /* Opposite child of root is dir-most child of sibling.*/
+    root->children[1-dir] = child;
+    if(child != NULL) child->parent = root;
+
+    /* Child of sibling is the root.*/
+    sibling->children[  dir] = root;
+    root->parent = sibling;
+
+    /* Parent of sibling is the grandparent. */
+    sibling->parent = gparent;
+    if(gparent != NULL)
+        gparent->children[CHILD_DIR(root)] = sibling;
+    else
+        tree->root = sibling;
+
+    return sibling;
+}
+
+/**Search the rbtree for a node that matches the key.
+ * If no such node is found, returns NULL.
+ * @param tree to search through.
+ * @param key to search for.
+ * @return found node.*/
+rbnode_t*
+s_find(rbtree_t *tree, intmax_t key)
+{
+    rbnode_t *node = tree->root;
+    while(node != NULL && node->key != key) {
+        node = node->children[node->key > key];
+    }
+    return node;
+}
+
+rbnode_t*
+s_closest(rbtree_t *tree, intmax_t key)
+{
+    rbnode_t *node = tree->root;
+    while(node != NULL && node->key != key) {
+        rbnode_t *child = node->children[node->key > key];
+        if(child == NULL) return node;
+        node = child;
+    }
+    return node;
+}
+
+/**Find the left-most node for this subtree.
+ * @param node root of the subtree to search through.
+ * @return left-most node.*/
+rbnode_t*
+s_node_min(rbnode_t *node)
+{
+    while(node->left != NULL) node = node->left;
+    return node;
+}
+
+/**Find the successor for the specified node.
+ * The successor is defined as the left-most node of the right sub-tree.
+ * (the smallest node larger than the root)
+ * @param node to search for.
+ * @return the successor.*/
+rbnode_t*
+s_node_successor(rbnode_t *node)
+{
+    if(node->right != NULL)
+        return s_node_min(node->right);
+    /* If the node has no left child (meaning that the node is larger than it's
+     * parents), we cycle up through the RHS of the parent tree (such that each
+     * parent is smaller than the child) until we reach a point by which the 
+     * child node is smaller than the parent.*/
+    rbnode_t *parent = node->parent;
+    while(parent != NULL && node == parent->right) {
+        node = parent;
+        parent = node->parent;
+    }
+    return parent;
+}
+
+/**Copy the data from one node onto another, keeping parent and child relations.
+ * @prarm tree for metadata purposes.
+ * @param dest destination node.
+ * @param src source node.*/
+void
+s_node_copy_value(rbtree_t *tree, rbnode_t *dest, rbnode_t *src)
+{
+    dest->key = src->key;
+    memcpy(dest->data, src->data, tree->objw);
+}
+
+/**Perform tree adjustments after insertion to rebalance the rbtree.
+ * @param tree to rebalance.
+ * @param node that was inserted.
+ * @param parent of the node.
+ * @param dir that the node was inserted in.*/
+void
+s_node_insert_fix(
+        rbtree_t *tree,
+        rbnode_t *node,
+        rbnode_t *parent,
+        bool dir)
+{
+    rbnode_t *gparent;
+    rbnode_t *uncle;
+    while((parent = node->parent) != NULL) {
+        if(parent->color == BLACK) return; /* Tree is valid. no fixes needed.*/
+        /*Parent is known to be red.*/
+        if((gparent = parent->parent) == NULL) {
+            /*Parent is red and the root. We can just fix it and return.*/
+            parent->color = BLACK;
+            return;
+        }
+        /* Parent is red and has a parent.
+         * We now need to fix the parent.*/
+        dir = CHILD_DIR(parent);
+        uncle = gparent->children[1-dir];
+        if(uncle == NULL || uncle->color == BLACK) {
+            /* Parent is red, but uncle (opposite child of gparent) is black.
+             * We need to rotate the gparent node such that the parent takes
+             * its place. However, if the current node is an inner child of 
+             * gparent, we need to rotate N into P.*/
+            if(node == parent->children[1-dir]) {
+                /* Node is an inner child. We need to rotate N and P first.*/
+                s_node_rotate(tree, parent, dir);
+                node = parent;
+                parent = gparent->children[dir];
+            }
+            /* N is not an inner child, we can rotate the tree properly.*/
+            s_node_rotate(tree, gparent, 1-dir);
+            parent->color = BLACK;
+            gparent->color = RED;
+            return;
+        }
+    }
+}
+
+/**Insert a node into the rbtree on the parent and direction given.
+ * @param tree to insert into.
+ * @param node to insert.
+ * @param parent node to insert onto.
+ * @param dir direction to insert node.*/
+void
+s_node_insert(rbtree_t *tree, rbnode_t *node, rbnode_t *parent, bool dir)
+{
+    node->color = RED;
+    node->left = NULL;
+    node->right = NULL;
+    node->parent = parent;
+    if(parent == NULL) {
+        tree->root = node;
+        return;
+    }
+    parent->children[dir] = node;
+    s_node_insert_fix(tree, node, parent, dir);
+}
+
+void
+s_node_remove_fixup(rbtree_t *tree, rbnode_t *node)
+{
+    bool dir;
+    rbnode_t *parent = node->parent;
+    rbnode_t *sibling;
+    rbnode_t *cnephew;
+    rbnode_t *dnephew;
+
+    dir = CHILD_DIR(node);
+    parent->children[dir] = NULL;
+    while((parent = node->parent) != NULL)
+    {
+        dir = CHILD_DIR(node);
+        sibling = parent->children[1-dir];
+        cnephew = parent->children[  dir];
+        dnephew = parent->children[1-dir];
+        if(sibling->color == RED)
+            goto case3;
+        if(dnephew != NULL && dnephew->color == RED)
+            goto case6;
+        if(cnephew != NULL && cnephew->color == RED)
+            goto case5;
+        if(parent->color == RED)
+            goto case4;
+
+        /* The parent, both nephews, and sibling are black. We need to paint
+         * the sibling black and move up a level.*/
+        sibling->color = RED;
+        node = parent;
+    }
+    return;
+
+case3:
+    /* The sibling is red, which means both nephews and the parent are black.
+     * We rotate the subtree so that the parent moves to become the siblings
+     * left child. The tree is then repainted.*/
+    s_node_rotate(tree, parent, dir);
+    parent->color = RED;
+    sibling->color = BLACK;
+    /* Now we are working on the sibling subtree.*/
+    sibling = cnephew;
+    dnephew = sibling->children[1-dir];
+    if(dnephew != NULL && dnephew->color == BLACK)
+        goto case6;
+    cnephew = sibling->children[dir];
+    if(cnephew != NULL && cnephew->color == RED)
+        goto case5;
+
+case4:
+    sibling->color = RED;
+    parent->color = BLACK;
+    return;
+
+case5:
+    s_node_rotate(tree, sibling, 1-dir);
+    sibling->color = RED;
+    cnephew->color = BLACK;
+    dnephew = sibling;
+    sibling = cnephew;
+
+case6:
+    s_node_rotate(tree, parent, dir);
+    sibling->color = parent->color;
+    parent->color = BLACK;
+    dnephew->color = BLACK;
+}
+
+void
+s_node_remove(rbtree_t *tree, rbnode_t *node)
+{
+    rbnode_t *parent = node->parent;
+    if(node->left != NULL && node->right != NULL) {
+        /* Node is a full tree. We can replace the node with it's successor to
+         * keep the balance.
+         * Needs to recurse if the successor has a right-most child, which is
+         * dealt with in the next case.*/
+        rbnode_t *successor = s_node_successor(node);
+        s_node_copy_value(tree, node, successor);
+        s_node_remove(tree, successor);
+        return;
+    } else if(node->left == NULL && node->right == NULL) {
+        if(parent == NULL) {
+            tree->root = NULL;
+            kfree(node);
+            return;
+        }
+        if(node->color == RED) {
+            parent->children[CHILD_DIR(node)] = NULL;
+            kfree(node);
+            return;
+        }
+        s_node_remove_fixup(tree, node);
+    } else {
+        /* Node has a single child. Because the child must be red as per spec,
+         * and this node must be black, we can simply replace the node
+         * with it's child and color it black.*/
+        rbnode_t *child = node->left == NULL ? node->right : node->left;
+        memcpy(node, child, sizeof(rbnode_t) + tree->objw);
+        node->parent = parent;
+        node->color = BLACK;
+        kfree(child);
+        return;
+    }
+}
+
+void
+__rbtree_new(rbtree_t *tree, size_t objw)
+{
+    *tree = (rbtree_t) {
+        .root = NULL,
+        .objw = objw,
+    };
+}
+
+void*
+rbtree_find(rbtree_t *tree, intmax_t key)
+{
+    rbnode_t *found = s_find(tree, key);
+    if(found == NULL) return NULL;
+    return found->data;
+}
+
+rbnode_t*
+s_node_new(rbtree_t *tree, intmax_t key, void *data)
+{
+    rbnode_t *node = kmalloc(sizeof(rbnode_t) + tree->objw);
+    if(data != NULL) memcpy(node->data, data, tree->objw);
+    node->key = key;
+    return node;
+}
+
+void*
+rbtree_insert(rbtree_t *tree, intmax_t key, void *data)
+{
+    assert(tree != NULL);
+
+    rbnode_t *node = s_closest(tree, key);
+    if(node != NULL && node->key == key) {
+        memcpy(node->data, data, tree->objw);
+    } else if(node != NULL) {
+        rbnode_t *child = s_node_new(tree, key, data);
+        s_node_insert(tree, child, node, node->key > key);
+        return child->data;
+    } else {
+        node = s_node_new(tree, key, data);
+        node->parent = NULL;
+        node->children[0] = node->children[1] = NULL;
+        node->color = BLACK;
+        tree->root = node;
+    }
+    return node->data;
+}
+
+void *rbtree_reserve(rbtree_t *tree, intmax_t key)
+{
+    assert(tree != NULL);
+
+    rbnode_t *node = s_closest(tree, key);
+    if(node != NULL && node->key == key) {
+        return node->data;
+    } else if(node != NULL) {
+        rbnode_t *child = s_node_new(tree, key, NULL);
+        s_node_insert(tree, child, node, node->key > key);
+        return child->data;
+    } else {
+        node = s_node_new(tree, key, NULL);
+        tree->root = node;
+    }
+    return node->data;
+}
+
diff --git a/klib/rbtree.h b/klib/rbtree.h
new file mode 100644
index 0000000..4376713
--- /dev/null
+++ b/klib/rbtree.h
@@ -0,0 +1,48 @@
+#ifndef JOVE_LIB_RBTREE_H
+#define JOVE_LIB_RBTREE_H 1
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "memory.h"
+
+typedef struct rbnode
+{
+    struct rbnode *parent;
+    struct rbnode *children[2];
+    intmax_t key;
+    bool color;
+    char data[];
+} rbnode_t;
+
+typedef struct rbtree
+{
+    rbnode_t *root;
+    size_t objw;
+} rbtree_t;
+
+/**Instantiate a new tree based on the given type.
+ * @param tree to instantiate into.
+ * @param type to instantiate for.*/
+#define rbtree_new(tree, type) __rbtree_new(tree, sizeof(type))
+void __rbtree_new(rbtree_t *tree, size_t objw);
+
+/**Find the data corresponding to the key in the tree.
+ * usage: rbtree_find(type)(tree, key);
+ * @param tree to search through.
+ * @param key to search for.
+ * @return */
+void *rbtree_find(rbtree_t *tree, intmax_t key);
+
+/**Insert a value into the given tree using the given key.
+ * If the key is already present within the tree, the existing data is
+ * overwritten.
+ * @param tree to insert into.
+ * @param key to insert.
+ * @param value to insert.
+ * @return pointer to inserted data.
+ * */
+void *rbtree_insert(rbtree_t *tree, intmax_t key, void *value);
+void *rbtree_reserve(rbtree_t *tree, intmax_t key);
+
+#endif
diff --git a/lib/sfmt.c b/klib/sfmt.c
index f903cbf..519fbf4 100644
--- a/lib/sfmt.c
+++ b/klib/sfmt.c
@@ -62,8 +62,11 @@ svfmt(char *s, size_t limit, const char *fmt, va_list ap)
             case '%':
                 s[si++] = '%';
                 break;
+            case 'p':
+                radix = 16;
+                alt = true;
             case 'b':
-                radix = 2;
+                if(radix == 10) radix = 2;
             case 'X':
                 upper = true;
             case 'x':
diff --git a/lib/spinlock.h b/klib/spinlock.h
index 75af28a..75af28a 100644
--- a/lib/spinlock.h
+++ b/klib/spinlock.h
diff --git a/lib/string.c b/klib/string.c
index 4bb1bad..4bb1bad 100644
--- a/lib/string.c
+++ b/klib/string.c
diff --git a/lib/toupper.c b/klib/toupper.c
index 807eb38..807eb38 100644
--- a/lib/toupper.c
+++ b/klib/toupper.c
diff --git a/lib/hashtable.c b/lib/hashtable.c
deleted file mode 100644
index 17f1e74..0000000
--- a/lib/hashtable.c
+++ /dev/null
@@ -1,109 +0,0 @@
-#include "hashtable.h"
-#include "string.h"
-#include "mem/memory.h"
-
-static size_t
-s_hash_function_mul(const void *data, size_t len)
-{
-    size_t hash = 1;
-    const char *cdata = (const char*)data;
-    for(size_t i = 0; i < len; i++) {
-        hash *= ((size_t)cdata[i]) + 1;
-    }
-    return hash;
-}
-
-static size_t
-s_hash_function_mul_s(const void *data, size_t _)
-{
-    return s_hash_function_mul(data, strlen(data));
-}
-
-void
-_hashtable_new(struct HashTable *table, size_t obj_size, size_t key_size)
-{
-    *table = (struct HashTable){
-        .buckets = NULL,
-        .bucket_count = 0,
-        .bucket_capacity = 2,
-        .obj_size = obj_size,
-        .key_size = key_size,
-        .hash_function = s_hash_function_mul
-    };
-    table->buckets = mem_alloc(sizeof(struct SLinkedList) * 2);
-}
-
-void
-_hashtable_news(struct HashTable *table, size_t obj_size)
-{
-    *table = (struct HashTable){
-        .buckets = NULL,
-        .bucket_count = 0,
-        .bucket_capacity = 2,
-        .obj_size = obj_size,
-        .key_size = -1,
-        .hash_function = s_hash_function_mul_s
-    };
-    table->buckets = mem_alloc(sizeof(struct SLinkedList) * 2);
-}
-
-void
-hashtable_insert(struct HashTable *table, const void *key, void *data)
-{
-    size_t hash = table->hash_function(key, table->key_size);
-    if(table->bucket_capacity == table->bucket_count) {
-        struct SLinkedList *old_buckets = table->buckets;
-        size_t old_buckets_count = table->bucket_count;
-
-        table->bucket_capacity *= 2;
-        table->bucket_count = 0;
-        table->buckets = mem_alloc(sizeof(struct SLinkedList) * table->bucket_capacity);
-        for(size_t i = 0; i < old_buckets_count; i++) {
-            for(struct SLLNode *node = old_buckets[i].head; node != NULL; node = node->next) {
-                struct HashTableValue *value = (struct HashTableValue*)(&node->data);
-                hashtable_insert(table, value->key, value->value);
-                mem_free(node);
-            }
-        }
-    }
-
-    size_t index = hash % table->bucket_capacity;
-    struct SLinkedList *bucket = &table->buckets[index];
-    struct SLLNode *node = mem_alloc(sizeof(struct SLLNode) + sizeof(struct HashTableValue) + table->obj_size);
-    struct HashTableValue *value = (struct HashTableValue*)(node->data);
-    
-    value->key = key;
-    memcpy(value->value, data, table->obj_size);
-
-    table->bucket_count++;
-    if(bucket->count == 0) {
-        sll_new(bucket, table->obj_size);
-        sll_push(bucket, node);
-        return;
-    }
-    for(struct SLLNode *onode = bucket->head; onode != NULL; onode = onode->next)
-    {
-        struct HashTableValue *ovalue = (struct HashTableValue*)onode->data;
-        size_t keylen = table->key_size > 0 ? table->key_size : strlen((const char*)key) + 1;
-        if(memcmp(ovalue->key, value->key, keylen) == 0) {
-            memcpy(ovalue->value, value->value, table->obj_size);
-            return;
-        }
-    }
-    sll_push(bucket, node);
-}
-
-void*
-_hashtable_get(struct HashTable *table, const void *key)
-{
-    size_t hash = table->hash_function(key, table->key_size);
-    size_t index = hash % table->bucket_capacity;
-    struct SLinkedList *bucket = &table->buckets[index];
-    for(struct SLLNode *node = bucket->head; node != NULL; node = node->next)
-    {
-        struct HashTableValue *value = (struct HashTableValue*)node->data;
-        size_t keylen = table->key_size > 0 ? table->key_size : strlen((const char*)value->key);
-        if(memcmp(key, value->key, keylen) == 0) return value->value;
-    }
-    return NULL;
-}
diff --git a/lib/hashtable.h b/lib/hashtable.h
deleted file mode 100644
index fe6f5c3..0000000
--- a/lib/hashtable.h
+++ /dev/null
@@ -1,34 +0,0 @@
-#ifndef JOVE_LIB_HASHTABLE_H
-#define JOVE_LIB_HASHTABLE_H 1
-
-#include <stddef.h>
-#include <stdint.h>
-#include "linkedlist.h"
-
-struct HashTableValue
-{
-    const void *key;
-    char value[];
-};
-
-struct HashTable {
-    struct SLinkedList *buckets;
-    size_t bucket_count;
-    size_t bucket_capacity;
-
-    size_t obj_size;
-    int key_size;
-    size_t (*hash_function)(const void*, size_t);
-};
-
-void _hashtable_new(struct HashTable *table, size_t obj_size, size_t key_size);
-#define hashtable_new(table, type, keytype) _hashtable_new(table, sizeof(type), sizeof(keytype))
-
-void _hashtable_news(struct HashTable *table, size_t obj_size);
-#define hashtable_news(table, type) _hashtable_news(table, sizeof(type))
-
-void hashtable_insert(struct HashTable *table, const void *key, void *data);
-void *_hashtable_get(struct HashTable *table, const void *key);
-#define hashtable_get(table, key, type) (type*)_hashtable_get(table, key)
-
-#endif
diff --git a/main.c b/main.c
index 91125af..a586287 100644
--- a/main.c
+++ b/main.c
@@ -1,26 +1,37 @@
-#include "arch/arch.h"
-#include "io/log.h"
-#include "mem/memory.h"
-#include "mem/zone.h"
-#include "boot/cmdline.h"
-#include "ird/initrd.h"
-#include "usr/tasking.h"
-#include "usr/umode.h"
-#include "lib/jove.h"
+#include "device/serial.h"
+#include "arch/processor.h"
+#include "arch/cpu.h"
+#include "memory.h"
+#include "commandline.h"
+#include "tasking.h"
+#include "initrd.h"
+#include "print.h"
 
+/**Setup datastructures and other fields required for the execution manager
+ * and interfaces used by init.*/
 void
 kernel_main(void)
 {
     serial_setup();
-    arch_tables_setup();
 
-    mem_setup();
+    cpu_setup();
+    processor_setup(proc_bsp);
 
-    cmdline_kernel_setup();
-    initrd_setup();
+    mm_setup_early();
+    mm_setup();
 
     tasking_setup();
-    umode_setup();
+    kpanic("Reached end of kernel_main\n");
+}
+
+/**Kernel execution context that sets up init.*/
+void
+kernel_stage2(void)
+{
+    cmdline_kernel_setup();
+
+    initrd_setup();
 
-    kpanic("Reached end of kernel main\n");
+    extern void kinit(void);
+    kinit();
 }
diff --git a/mem/memory.c b/mem/memory.c
deleted file mode 100644
index 26bbbd8..0000000
--- a/mem/memory.c
+++ /dev/null
@@ -1,10 +0,0 @@
-#include "memory.h"
-#include "zone.h"
-
-void
-mem_setup(void)
-{
-    mem_zone_setup_standard();
-    mem_paging_setup();
-    mem_slab_setup();
-}
diff --git a/mem/memory.h b/mem/memory.h
deleted file mode 100644
index 251c6f5..0000000
--- a/mem/memory.h
+++ /dev/null
@@ -1,94 +0,0 @@
-#ifndef JOVE_MEM_H
-#define JOVE_MEM_H 1
-
-#define PAGE_SHIFT 12
-#define PAGE_SIZE (1 << PAGE_SHIFT)
-#define PAGE_MASK (PAGE_SIZE - 1)
-
-#define KiB 1024ULL
-#define MiB (KiB * KiB)
-#define GiB (MiB * KiB)
-#define TiB (GiB * KiB)
-
-#include "lib/spinlock.h"
-#include "sys/types.h"
-
-typedef struct page_directory
-{
-    spinlock_t lock;
-    size_t id;
-    size_t ref;
-    physptr_t phys;
-    void *virt;
-} page_directory_t;
-
-#include "slab.h"
-
-extern page_directory_t *current_page_directory;
-
-/**Setup the kernel structures responsible for handling physical memory translation.*/
-void mem_paging_setup(void);
-
-/**Check if a given pointer is valid.
- * @param ptr pointer to check.
- * @return if the pointer is valid.*/
-bool mem_check_ptr(const void *ptr);
-
-/** Return the physical memory mapping for the given address.
- * @param pd page directory to get mapping in.
- * @param addr address to get mapping for.
- * @return HAL compliant page mapping.*/
-page_mapping_t mem_get_mapping_as(page_directory_t *pd, uintptr_t addr);
-
-/** Return the physical memory mapping for the given address.
- * @param addr address to get mapping for.
- * @return HAL compliant page mapping.*/
-page_mapping_t mem_get_mapping(uintptr_t addr);
-
-/** Map a page mapping to a given virtual address.
- * @param pd pointer to the page directory to edit.
- * @param mapping mapping to apply.
- * @param virt virtual address to map to. */
-void mem_set_mapping_as(page_directory_t *pd, page_mapping_t mapping, uintptr_t virt);
-
-/** Map a page mapping to a given virtual address.
- * @param pd pointer to the page directory to edit.
- * @param mapping mapping to apply.
- * @param virt virtual address to map to. */
-void mem_set_mapping(page_mapping_t mapping, uintptr_t virt);
-
-/** Make sure the range indicated is available in memory for specified pd
- * If necessary, allocate new pages using the passed flags
- * @param pd pointer to page directory to edit
- * @param from start of the range
- * @param to end of the range
- * @param rw flag to mark page is writeable
- * @param user flag to mark page as user accessable*/
-void mem_ensure_range_as(page_directory_t *pd, uintptr_t from, uintptr_t to, page_flags_t flg);
-
-/**Make sure the range indicated is available in memory
- * If necessary, allocate new pages using the passed flags
- * @param from start of the range.
- * @param to end of the range.
- * @param rw flag to mark page is writeable.
- * @param user flag to mark page as user accessable*/
-void mem_ensure_range(uintptr_t from, uintptr_t to, page_flags_t flg);
-
-void mem_slab_setup(void);
-void mem_slabcache_new(struct SlabCache *cache, char *name, size_t objsize);
-
-void* mem_slab_alloc(struct SlabCache *cache);
-void mem_slab_free(struct SlabCache *cache, void *ptr);
-
-void* mem_alloc(size_t width);
-void mem_free(void *ptr);
-
-/*Physical*/
-
-physptr_t mem_phys_alloc(size_t pages);
-void mem_phys_reserve(physptr_t start, physptr_t end);
-void mem_phys_release(physptr_t start, physptr_t end);
-
-void mem_setup(void);
-
-#endif
diff --git a/mem/phys.c b/mem/phys.c
deleted file mode 100644
index bf56b77..0000000
--- a/mem/phys.c
+++ /dev/null
@@ -1,39 +0,0 @@
-#include "memory.h"
-#include "zone.h"
-#include "lib/jove.h"
-
-void
-mem_phys_reserve(physptr_t start, physptr_t end)
-{
-    size_t zone = mem_zone_for(start);
-    size_t limit = mem_zone_bound_upper(zone);
-
-    if(end > limit) {
-        mem_phys_reserve(limit, end);
-        end = limit;
-    }
-    mem_zone_resv(MEM_ZONE_STANDARD, start, end);
-}
-
-void 
-mem_phys_release(physptr_t start, physptr_t end)
-{
-    size_t zone = mem_zone_for(start);
-    size_t limit = mem_zone_bound_upper(zone);
-
-    if(end > limit) {
-        mem_phys_release(limit, end);
-        end = limit;
-    }
-    mem_zone_free(MEM_ZONE_STANDARD, start, end);
-}
-
-physptr_t
-mem_phys_alloc(size_t pages)
-{
-    if(mem_zone_pages_free(MEM_ZONE_HIGHER) >= pages)
-        return mem_zone_alloc(MEM_ZONE_HIGHER, pages);
-    if(mem_zone_pages_free(MEM_ZONE_STANDARD) >= pages)
-        return mem_zone_alloc(MEM_ZONE_STANDARD, pages);
-    kpanic("Kernel ran out of physical memory!\n");
-}
diff --git a/mem/slab.h b/mem/slab.h
deleted file mode 100644
index 074d278..0000000
--- a/mem/slab.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef JOVE_MEMORY_SLAB_H
-#define JOVE_MEMORY_SLAB_H 1
-
-#include <stdint.h>
-#include <stddef.h>
-#include <stdbool.h>
-
-#define SLABCACHE_NAME_LIMIT 32
-struct SlabCache
-{
-    char name[SLABCACHE_NAME_LIMIT];
-
-    struct SlabDescriptor *list_free;
-    struct SlabDescriptor *list_partial;
-    struct SlabDescriptor *list_full;
-
-    size_t obj_size;
-    size_t slab_pages;
-};
-
-struct SlabDescriptor
-{
-    struct SlabDescriptor *prev;
-    struct SlabDescriptor *next;
-    void *slab_base;
-    void *obj_base;
-
-    size_t free_count;
-    int free_index;
-    uintptr_t free[];
-};
-
-#endif
diff --git a/mem/zone.h b/mem/zone.h
deleted file mode 100644
index c0b0f52..0000000
--- a/mem/zone.h
+++ /dev/null
@@ -1,71 +0,0 @@
-#ifndef JOVE_MEM_ZONE_H
-#define JOVE_MEM_ZONE_H 1
-
-#include <stdint.h>
-#include "lib/buddymap.h"
-
-enum {
-    MEM_ZONE_STANDARD = 0, /* First GiB of physical memory. */
-    MEM_ZONE_HIGHER,
-    MEM_ZONE_COUNT
-};
-
-#define MEM_ZONE_STANDARD_BASE 0
-#define MEM_ZONE_STANDARD_LIMIT (1 * GiB)
-#define MEM_ZONE_HIGHER_BASE MEM_ZONE_STANDARD_LIMIT
-
-#define MEM_BUDDY_ORDERS 12
-struct PhysicalMemoryZone
-{
-    const char *name;
-
-    uintptr_t base;
-    uintptr_t limit;
-
-    struct BuddyMap freemap;
-};
-
-/**Return the zone index for the given address
- * @param addr address to look up
- * @return zone index*/
-int mem_zone_for(uintptr_t addr);
-
-/**Return the lower bound for the given zone index.
- * @param zone index into zones.
- * @return lower bound.*/
-uintptr_t mem_zone_bound_lower(size_t zone);
-
-/**Return the upper bound for the given zone index.
- * @param zone index into zones.
- * @return upper bound.*/
-uintptr_t mem_zone_bound_upper(size_t zone);
-
-/**Return the number of pages free in the given zone.
- * @param zone index into zones.
- * @return number of free pages.*/
-size_t mem_zone_pages_free(size_t zone);
-
-/** Using a given zone, reserve a range of physical addresses
- * @param zone identifier of zone to modify
- * @param base starting address to reserve
- * @param limit ending address to reserve
- * @return error code or 0 if success */
-int mem_zone_resv(size_t zone, uintptr_t base, uintptr_t limit);
-
-/** Using a given zone, free a range of physical addresses
- * @param zone identifier of zone to modify
- * @param base starting address to free
- * @param limit ending address to free
- * @return error code or 0 if success*/
-int mem_zone_free(size_t zone, uintptr_t base, uintptr_t limit);
-
-/** Allocate a number of pages from the given zone
- * @param zone identifier of the zone to modify
- * @param pages number of pages to allocate
- * @return physical memory address of allocation
- *         zero if allocation failed*/
-uintptr_t mem_zone_alloc(size_t zone, size_t pages);
-
-void mem_zone_setup_standard(void);
-
-#endif
diff --git a/memory/alloc/calloc.c b/memory/alloc/calloc.c
new file mode 100644
index 0000000..cd272af
--- /dev/null
+++ b/memory/alloc/calloc.c
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#include "malloc.h"
+#include <string.h>
+
+void*
+__calloc_impl(heap_cache_t *cache, size_t nmemb, size_t w)
+{
+    w = REALW(w);
+    void *ptr = __malloc_impl(cache, w * nmemb);
+    if(ptr == NULL) return NULL;
+
+    /* Zero newly allocated memory as per spec.*/
+    memset(ptr, 0, w * nmemb);
+    return ptr;
+}
diff --git a/memory/alloc/free.c b/memory/alloc/free.c
new file mode 100644
index 0000000..e2cc060
--- /dev/null
+++ b/memory/alloc/free.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#include "malloc.h"
+#include "assert.h"
+
+bucket_t*
+__bucket_from_obj(heap_cache_t *cache, bucket_obj_t *obj)
+{
+    assert(cache != NULL);
+    assert(cache->head != NULL);
+    /* Buckets are always aligned to the nearest page boundary, and that the 
+     * metadata is always below the object. We use this fact to quickly find 
+     * owning buckets.*/
+    uintptr_t objptr = (uintptr_t)obj;
+    uintptr_t bktptr = objptr & ~0xFFF;
+    while(1) {
+        /* If the page boundary is below the head, we are below the heap memory
+         * region and can stop.*/
+        if(bktptr < (uintptr_t)cache->head) return NULL;
+
+        /* At each page boundary below the object, check for the heap checksum.
+         * If it is found, we can assume that we found a bucket.*/
+        bucket_t *bucket = (bucket_t*)bktptr;
+        if(OBJ_VALID(bucket)) {
+            if(bucket->limit > objptr) return NULL;
+            return bucket;
+        }
+
+        bktptr -= BUCKET_ALIGN;
+    }
+}
+
+void
+__free_impl(heap_cache_t *cache, void *ptr)
+{
+    DBGPRINT("free: asking to free ptr %p\n", ptr);
+    assert(cache != NULL);
+    /* free(NULL) does nothing.*/
+    if(ptr == NULL) return;
+
+    /* Make sure the pointer actually comes from the heap.*/
+    assert((uintptr_t)ptr < (uintptr_t)cache->tail);
+    assert((uintptr_t)ptr > (uintptr_t)cache->head);
+    bucket_obj_t *obj = OBJ_FROM_PTR(ptr);
+    assert(OBJ_VALID(obj));
+
+    /* Mask the taken bit in the object to mark it free.*/
+    DBGPRINT("free: masking taken bit in object %p (was %i, now ", 
+            obj, obj->size_taken);
+    obj->size_taken &= ~1;
+    DBGPRINT("%i)\n", obj->size_taken);
+
+    /* If the buckets' lastfree is greater than this new free object, this 
+     * object will be the lastfree.*/
+    bucket_t *bucket = __bucket_from_obj(cache, obj);
+    if(bucket != NULL && bucket->firstfree > obj)
+        bucket->firstfree = obj;
+
+    /* Start trying to merge this free object with the next object.
+     * If the object after is taken, do nothing.*/
+    bucket_obj_t *after = OBJ_AFTER(obj);    
+    if((uintptr_t)after > bucket->limit) return;
+    assert(OBJ_VALID(after));
+    if(OBJ_TAKEN(after)) return;
+    
+    /* Merge with the next object.
+     * from:
+     * [meta| -objw-][meta| -afterw-]
+     * to:
+     * [meta| ---------objw---------]*/
+    DBGPRINT("free: obj %p merging with adjacent free object %p (was %i, now \n", 
+            obj, after, obj->size_taken);
+    obj->size_taken += sizeof(bucket_obj_t) + after->size_taken;
+    DBGPRINT("%i)\n", obj->size_taken);
+}
diff --git a/memory/alloc/malloc.c b/memory/alloc/malloc.c
new file mode 100644
index 0000000..ba1e2d2
--- /dev/null
+++ b/memory/alloc/malloc.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#include "malloc.h"
+#include "assert.h"
+#include "jove.h"
+#include "memory/bump.h"
+
+/**Allocate memory for a new bucket in the heap.
+ * Automatically aligns new memory to BUCKET_ALIGN.
+ * Instantiates a new free object spanning the entire bucket.
+ * Then adds the new bucket to the heap cache.
+ * If sbrk encounters an error, pass through errno and return NULL.
+ * @param cache to allocate for.
+ * @param objw width of the object the bucket is assumed to hold.
+ * @return bucket created by this function.*/
+bucket_t*
+s_bucket_new(heap_cache_t *cache, size_t objw)
+{
+    DBGPRINT("malloc: ask for new bucket for cache %p with objw %i\n", cache, objw);
+    size_t bucketw = BUCKET_WIDTH(objw);
+    /* Assuming sbrk allocates memory for after the program break, make sure
+     * we allocate enough for the requested bucket width and any adjustments
+     * to ensure page alignment.*/
+    uintptr_t pbrk = (uintptr_t)bump_where();
+    uintptr_t brko = pbrk % BUCKET_ALIGN;
+    uintptr_t nbrk = (uintptr_t)bump_alloc(bucketw + brko);
+
+    bucket_t *bucket = (bucket_t*)(nbrk + brko);
+    DBGPRINT("malloc: got new bucket at %p\n", bucket);
+
+    *bucket = (bucket_t){
+        .checksum = OBJ_CHECKSUM,
+        .next = NULL,
+        .limit = (uintptr_t)bucket + bucketw,
+    };
+    /* Create a new object spanning the entire bucket. This new object will
+     * be the first free.*/
+    bucket_obj_t *obj0 = (bucket_obj_t*)bucket->objs;
+    *obj0 = (bucket_obj_t) {
+        .checksum = OBJ_CHECKSUM,
+        .size_taken = bucketw - sizeof(bucket_t) - sizeof(bucket_obj_t)
+    };
+    bucket->firstfree = obj0;
+
+    /* If the cache is empty, this will be the first and last bucket.*/
+    if(cache->head == NULL) {
+        cache->head = cache->tail = bucket;
+        return bucket;
+    }
+    /* Add the bucket to the heap cache bucket list.*/
+    cache->tail->next = bucket;
+    cache->tail = bucket;
+    return bucket;
+}
+
+/**Given an existing object and a size, split the object so that the original
+ * has size w.
+ * If the object is smaller than or is already the correct size, do nothing.
+ * Space after the split is allocated to a new free object after the resized
+ * original.
+ * If the original == bucket->firstfree, the new object is assigned to 
+ * that variable.
+ * If the heap is corrupted, assert fail.
+ * @param bucket object's parent bucket.
+ * @param parent object to split.
+ * @param w requested size for original object. */
+void
+s_obj_take_split(bucket_t *bucket, bucket_obj_t *parent, size_t w)
+{
+    DBGPRINT("malloc: requesting to split object %p (last %p) for size %i (was %i)\n",
+           bucket, parent, w, parent->size_taken);
+
+    /* Assert fail on corrupted heap.*/
+    assert(OBJ_VALID(bucket));
+    assert(OBJ_VALID(parent));
+    assert(w >= OBJ_SIZE_MIN);
+
+    size_t objw = OBJ_WIDTH(parent);
+    if(w == objw) { /* Obj is already correct size, take and ignore.*/
+        if(bucket->firstfree == parent)
+            bucket->firstfree = OBJ_AFTER(parent);
+        /* Ensure that firstfree does not exceed bucket limits.*/
+        if((uintptr_t)bucket->firstfree > bucket->limit)
+            bucket->firstfree = NULL;
+        DBGPRINT("malloc: Object is already right size, ignoring\n");
+
+        /* Mark object as taken.*/
+        parent->size_taken = w | 1;
+        return;
+    }
+    /* New object created by split will be the original width minus the new
+     * width and metadata size.
+     *
+     * from:
+     * [meta| --------objw-------- ]
+     *
+     * to:
+     * [meta| -w- ][meta| -afterw- ]*/
+    size_t afterw = objw - sizeof(bucket_obj_t) - w;
+
+    parent->size_taken = w | 1;
+    bucket_obj_t *obj = OBJ_AFTER(parent);
+    DBGPRINT("malloc: New object created inplace at %p with size %i\n",
+            obj, afterw);
+
+    /* In-place allocate after obj.*/
+    *obj = (bucket_obj_t){
+        .checksum = OBJ_CHECKSUM,
+        .size_taken = afterw,
+    };
+    if(bucket->firstfree == parent)
+        bucket->firstfree = obj;
+}
+
+/* Look for a free object in the given bucket that closest matches size w.
+ * Uses bucket->firstfree as a starting point to save checks against taken
+ * objects.
+ * If the heap is corrupted, assert fail.
+ * If there are no good objects in this bucket, return NULL.
+ * @param bucket to search in.
+ * @param w to search for.
+ * @return best-fitting object or NULL if none are found.
+ * */
+bucket_obj_t*
+s_obj_bestfit(bucket_t *bucket, size_t w)
+{
+    assert(bucket != NULL);
+    assert(OBJ_VALID(bucket));
+
+    bucket_obj_t *best = NULL;
+    bucket_obj_t *obj = bucket->firstfree;
+    if(obj == NULL) return NULL;
+    for(; (uintptr_t)obj < bucket->limit; obj = OBJ_AFTER(obj))
+    {
+        assert(OBJ_VALID(obj));
+        if(OBJ_TAKEN(obj)) continue;
+        size_t objw = OBJ_WIDTH(obj);
+        if(objw < w) continue;
+        if(best == NULL) best = obj;
+
+        size_t bestw = OBJ_WIDTH(best);
+        if(objw < bestw) best = obj;
+    }
+    
+    DBGPRINT("malloc: Bucket %p returns best fit at %p for size %i ",
+            bucket, best, w);
+    if(best != NULL) { DBGPRINT("(size %i)\n", best->size_taken); }
+    else { DBGPRINT("(is NULL)\n"); }
+
+    return best;
+}
+
+/**Searching through the entire heap, or until an object is found, find a
+ * free object that best fits the requested width and place the resulting
+ * bucket in the passed pointer.
+ * If the heap is corrupted, assert fail.
+ * If no object is found in any of the buckets, return NULL.
+ * @param cache heap to search through.
+ * @param w object width to search for.
+ * @param bucket pointer to bucket pointer owning the returned bucket.
+ *        If no object is found, variable is untouched.
+ * @return object that fits the given width.*/
+bucket_obj_t*
+s_bucket_bestfit(heap_cache_t *cache, size_t w, bucket_t **bucket)
+{
+    *bucket = cache->head;
+    for(; *bucket != NULL; *bucket = (*bucket)->next)
+    {
+        bucket_obj_t *obj = s_obj_bestfit(*bucket, w);
+        /* Object is already found, don't waste cycles searching through
+         * the entire heap.*/
+        if(obj != NULL) return obj;
+    }
+    return NULL;
+}
+
+void*
+__malloc_impl(heap_cache_t *cache, size_t w)
+{
+    assert(cache != NULL);
+    /* w == 0 is ub, just return NULL.*/
+    if(w == 0) return NULL;
+    /* Ensure that w is valid.*/
+    w = REALW(w);
+
+    DBGPRINT("malloc: Asking to malloc for size %i\n", w);
+
+    bucket_t *bucket = NULL;
+    bucket_obj_t *obj = s_bucket_bestfit(cache, w, &bucket);
+    if(obj == NULL) {
+        /* No bucket in the heap has an appropriate space.
+         * Allocate a new bucket and take the first object.
+         * If the bucket allocation fails, return -1 and pass errno through.*/
+        bucket = s_bucket_new(cache, w);
+        if(bucket == NULL) return (void*)(-1);
+        obj = (bucket_obj_t*)bucket->objs;
+    }
+    /* Split the bucket to make the object bestfit.*/
+    s_obj_take_split(bucket, obj, w);
+    return obj->data;
+}
diff --git a/memory/alloc/malloc.h b/memory/alloc/malloc.h
new file mode 100644
index 0000000..abe87ff
--- /dev/null
+++ b/memory/alloc/malloc.h
@@ -0,0 +1,183 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#ifndef _MALLOC_H
+#define _MALLOC_H 1
+
+/* A bucket-based malloc implementation for 2^n sized objects.
+ * Allocates memory at pbrk for use in dynamic allocations, called "objects".
+ * Each object is pre-empted by metadata, which stores a checksum, the width, 
+ * and a bit to mark it as taken.
+ *
+ * Each alloc-able region is pre-empted by a "bucket", which stores metadata
+ * about the bucket's state, the width, the first free object, and the next
+ * bucket in the chain.
+ *
+ * Buckets are allocated when needed. The width of the new bucket is determined
+ * by the object that needs the bucket.
+ * Buckets are always page aligned, and the size is a multiple of a page width.
+ *
+ * Dependencies:
+ *  stddef.h
+ *  stdint.h
+ *  errno.h
+ *  assert.h
+ *      assert
+ *  string.h
+ *      memset
+ *      memcpy
+ *  unistd.h
+ *      sbrk
+ *      brk
+ *
+ * with MALLOC_DBG:
+ *  stdio.h
+ *      printf*/
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define DBGPRINT(...)
+#ifdef MALLOC_DBG
+#include "io/log.h"
+#undef DBGPRINT
+#define DBGPRINT(...) klogf(__VA_ARGS__)
+#endif
+
+/* Bucket checksum is a 64-bit value containing the string "BUCKET\0\0"*/
+#define OBJ_CHECKSUM \
+    (((uintmax_t)'B') | \
+    ((uintmax_t)'U' << 8) | \
+    ((uintmax_t)'C' << 16) | \
+    ((uintmax_t)'K' << 24) | \
+    ((uintmax_t)'E' << 32) | \
+    ((uintmax_t)'T' << 40))
+
+/* For an object to be valid, the object must have the correct checksum.*/
+#define OBJ_VALID(obj) (obj->checksum == OBJ_CHECKSUM)
+
+/* Object width is assumed to be a multiple of two. The first bit is reserved
+ * for the taken flag.*/
+#define OBJ_WIDTH(obj) (obj->size_taken & ~1)
+#define OBJ_TAKEN(obj) (obj->size_taken & 1)
+
+/* Gets the object struct after this object.
+ * Since objects are allocated in-place, we can get the next object using
+ * the object's size and it's pointer to the start of data.
+ *
+ * The same is true for getting the metadata for any given data pointer.
+ * We take the pointer and subtract the size of the object struct from it
+ * since the metadata is behind the actual data.*/
+#define OBJ_AFTER(obj) \
+    ((bucket_obj_t*)(((uintptr_t)obj->data) + OBJ_WIDTH(obj)))
+#define OBJ_FROM_PTR(ptr) ((bucket_obj_t*)((uintptr_t)ptr - sizeof(bucket_obj_t)));
+
+typedef struct bucket_obj
+{
+    uintmax_t checksum;
+    size_t size_taken;
+    char data[];
+} bucket_obj_t;
+
+#define LOG2(n) ((31) - __builtin_clz(n))
+/* Buckets are always aligned to the page boundary for cache friendliness.*/
+#define BUCKET_ALIGN (4096)
+/* Buckets should always be a multiple of the page width, expanding with the
+ * initial object size.*/
+#define BUCKET_WIDTH(w) \
+    (1UL << (12 + (w < BUCKET_ALIGN ? 0 : LOG2(w + 1) - 11)))
+
+/* Bucket metadata is stored behind the object metadata.*/
+typedef struct bucket
+{
+    size_t checksum;
+    struct bucket *next;
+
+    uintptr_t limit;
+    bucket_obj_t *firstfree; /* Helpful for fast object allocations.*/
+    char objs[];
+} bucket_t;
+
+/* The overall size of an object (data + metadata) should be 2*metadata.*/
+#define OBJ_SIZE_MIN (sizeof(bucket_obj_t))
+/* Data width is always a power of two.*/
+#define REALW(n) \
+    (n < OBJ_SIZE_MIN ? OBJ_SIZE_MIN : (1UL << (LOG2(n) + 1)))
+
+typedef struct heap_cache
+{
+    bucket_t *head;
+    bucket_t *tail;
+} heap_cache_t;
+
+/**Given the heap cache and an object, find the bucket to which the object
+ * belongs.
+ * Since buckets are always page aligned, we can check each page boundary
+ * for the checksum until we find it, then check the limit.
+ * Since we also know the first bucket in the cache, we can also check if the
+ * passed object is invalid and return NULL.
+ * @param heap cache.
+ * @param obj to find the bucket for.
+ * @return bucket owning obj, or NULL if obj is invalid.*/
+bucket_t *__bucket_from_obj(heap_cache_t *heap, bucket_obj_t *obj);
+
+/**Allocate w bytes into the given heap.
+ * If w == 0, returns NULL.
+ * If w is not a power of 2, rounds to the nearest pow2.
+ * If the heap is corrupted, assert fail.
+ * If the program is OOM, errno is assumed to be set and returns (void*)-1
+ * @param heap cache.
+ * @param w n-bytes to allocate.
+ * @return pointer to allocated memory.*/
+void* __malloc_impl(heap_cache_t *heap, size_t w);
+
+/**Allocate a contiguous array of nmemb members each w wide.
+ * Newly allocated memory is zero'd.
+ * If w == 0 || nmemb == 0, returns NULL
+ * If w is not a power of 2, rounds to nearest pow2
+ * If the heap is corrupted, assert fail
+ * If the program is OON, ernno is assumed to be set and returns (void*)-1
+ * @param heap cache.
+ * @param nmemb number of members.
+ * @param w number of bytes per member.
+ * @return pointer to allocated memory.*/
+void* __calloc_impl(heap_cache_t *heap, size_t nmemb, size_t w);
+
+/**Resize the given allocated memory region to fit w.
+ * If w is less than the original width, does nothing.
+ * If w == 0, frees p
+ * If the heap is corrupted, assert fail.
+ * If the heap is OOM, errno is assumed to be set and returns (void*)-1
+ * @param heap cache.
+ * @param p pointer to reallocate.
+ * @param w width to fit p to.
+ * @return pointer to memory allocated to fit w.*/
+void* __realloc_impl(heap_cache_t *heap, void *p, size_t w);
+
+/**Resize the given allocated contiguous array to fit nmemb members of w width
+ * objects.
+ * Zeros the new members excluding already existing data.
+ * If w * nmemb is less than the original width, does nothing.
+ * If w == 0 || nmemb == 0, frees p
+ * If the heap is corrupted, assert fail.
+ * If the heap is OOM, errno is assumed to be set and returns (void*)-1
+ * @param heap cache.
+ * @param p pointer to reallocate.
+ * @param nmemb number of members.
+ * @param w width to fit p to.
+ * @return pointer to memory allocated to fit w * nmemb.*/
+void* __reallocarray_impl(heap_cache_t *heap, void *p, size_t nmemb, size_t w);
+
+/**Free a pointer in the given heap.
+ * If p == NULL, do nothing.
+ * If p does not fall in the range of heap, assert fail.
+ * If the heap is corrupted, assert fail.
+ * @param heap cache.
+ * @param p pointer to free.*/
+void  __free_impl(heap_cache_t *heap, void *p);
+
+#endif
diff --git a/memory/alloc/realloc.c b/memory/alloc/realloc.c
new file mode 100644
index 0000000..1b90e8c
--- /dev/null
+++ b/memory/alloc/realloc.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#include "malloc.h"
+#include "assert.h"
+#include "string.h"
+
+void*
+__realloc_impl(heap_cache_t *cache, void *ptr, size_t w)
+{
+    if(w == 0) {
+        DBGPRINT("realloc: called with w == 0, freeing %p\n", ptr);
+        __free_impl(cache, ptr);
+        return NULL;
+    }
+    if(ptr == NULL) {
+        DBGPRINT("realloc: called with NULL ptr, alloc %i\n", w);
+        return __malloc_impl(cache, w);
+    }
+
+    w = REALW(w);
+    bucket_obj_t *obj = OBJ_FROM_PTR(ptr);
+
+    assert(OBJ_VALID(obj));
+    size_t objw = OBJ_WIDTH(obj);
+    if(objw > w) return ptr;
+
+    size_t wdiff = w - objw;
+    DBGPRINT("realloc: ptr %p needs %i new bytes\n", ptr, wdiff);
+
+    bucket_obj_t *after = OBJ_AFTER(obj);
+    size_t afterw = 0;
+    bucket_t *bucket = __bucket_from_obj(cache, obj);
+    void *newptr = NULL;
+
+    if(bucket == NULL)
+        goto resize_fail;
+
+    if((uintptr_t)after > bucket->limit) goto resize_fail;
+    assert(OBJ_VALID(after));
+    afterw = OBJ_WIDTH(after);
+
+    if(OBJ_TAKEN(after))
+        goto resize_fail;
+    
+    DBGPRINT("realloc: obj %p after obj %p is free (w %i)\n", after, obj, afterw);
+    if(objw + sizeof(bucket_obj_t) + afterw < w)
+        goto resize_fail;
+
+    obj->size_taken = w | 1;
+    if(bucket->firstfree == after)
+        bucket->firstfree = OBJ_AFTER(obj);
+
+    after = OBJ_AFTER(obj);
+    *after = (bucket_obj_t){
+        .checksum = OBJ_CHECKSUM,
+        .size_taken = afterw - wdiff
+    };
+    DBGPRINT("realloc: moved obj %p (%i) to resize obj %p (%i)\n", 
+            after, after->size_taken, obj, obj->size_taken);
+    return ptr;
+
+resize_fail:
+    DBGPRINT("realloc: could not resize existing object, calling malloc\n");
+    newptr = __malloc_impl(cache, w);
+    memcpy(newptr, ptr, obj->size_taken & ~1);
+    __free_impl(cache, ptr);
+    return newptr;
+}
diff --git a/memory/alloc/reallocarray.c b/memory/alloc/reallocarray.c
new file mode 100644
index 0000000..c58dfe9
--- /dev/null
+++ b/memory/alloc/reallocarray.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) Jon Santmyer.
+ * This source file is released under the LGPL Version 3 as detailed in
+ * the LICENSE file provided in the following repository:
+ * https://git.jonsantmyer.com/heap/
+ * */
+
+#include "malloc.h"
+#include "assert.h"
+#include "string.h"
+
+void*
+__reallocarray_impl(heap_cache_t *cache, void *ptr, size_t nmemb, size_t w)
+{
+    /* Free if w == nmemb == 0*/
+    if(w == 0 || nmemb == 0) {
+        __free_impl(cache, ptr);
+        return NULL;
+    }
+    
+    if(ptr == NULL)
+        return __calloc_impl(cache, nmemb, w);
+
+    size_t allocw = w * nmemb;
+    w = REALW(w);
+    
+    bucket_obj_t *obj = OBJ_FROM_PTR(ptr);
+    assert(OBJ_VALID(obj));
+    size_t oldw = OBJ_WIDTH(obj);
+    if(allocw < oldw) return ptr;
+
+    ptr = __realloc_impl(cache, ptr, allocw);
+    size_t wdiff = allocw - oldw;
+    void *zeroat = (void*)(((uintptr_t)ptr) + oldw);
+    memset(zeroat, 0, wdiff);
+    return ptr;
+}
diff --git a/memory/bump.c b/memory/bump.c
new file mode 100644
index 0000000..a6b0228
--- /dev/null
+++ b/memory/bump.c
@@ -0,0 +1,33 @@
+#include "bump.h"
+#include "memory.h"
+
+static void *s_next_free;
+
+void*
+bump_where(void)
+{
+    return s_next_free;
+}
+
+void *bump_alloc(size_t size)
+{
+    void *ret = s_next_free;
+    s_next_free = (void*)((uintptr_t)s_next_free + size);
+    vm_ensure(
+            (uintptr_t)ret,
+            (uintptr_t)s_next_free,
+            (page_flags_t) {
+                .present = true,
+                .writeable = true,
+                .useraccess = false,
+                .executable = false
+            });
+    return ret;
+}
+
+void
+bump_setup(void)
+{
+    extern void *_kernel_end;
+    s_next_free = (void*)&_kernel_end;
+}
diff --git a/memory/bump.h b/memory/bump.h
new file mode 100644
index 0000000..5b1c2b7
--- /dev/null
+++ b/memory/bump.h
@@ -0,0 +1,10 @@
+#ifndef JOVE_MEMORY_BUMP_H
+#define JOVE_MEMORY_BUMP_H 1
+
+#include <stddef.h>
+
+void *bump_where(void);
+void *bump_alloc(size_t size);
+void bump_setup(void);
+
+#endif
diff --git a/memory/memory.c b/memory/memory.c
new file mode 100644
index 0000000..2a0e8f2
--- /dev/null
+++ b/memory/memory.c
@@ -0,0 +1,39 @@
+#include "memory.h"
+#include "alloc/malloc.h"
+#include "zone.h"
+#include "bump.h"
+
+heap_cache_t heap_cache;
+
+void*
+kmalloc(size_t width)
+{
+    return __malloc_impl(&heap_cache, width);
+}
+
+void*
+krealloc(void *ptr, size_t width)
+{
+    return __realloc_impl(&heap_cache, ptr, width);
+}
+
+void
+kfree(void *ptr)
+{
+    __free_impl(&heap_cache, ptr);
+}
+
+void
+mm_setup_early(void)
+{
+    pm_zone_setup();
+    vm_setup_early();
+}
+
+void
+mm_setup(void)
+{
+    heap_cache = (heap_cache_t) { NULL, NULL };
+    bump_setup();
+    vm_setup();
+}
diff --git a/memory/phys.c b/memory/phys.c
new file mode 100644
index 0000000..4d9dbc1
--- /dev/null
+++ b/memory/phys.c
@@ -0,0 +1,39 @@
+#include "memory.h"
+#include "zone.h"
+#include "jove.h"
+
+void
+pm_reserve(physptr_t start, physptr_t end)
+{
+    size_t zone = pm_zone_for(start);
+    size_t limit = pm_zone_bound_upper(zone);
+
+    if(end > limit) {
+        pm_reserve(limit, end);
+        end = limit;
+    }
+    pm_zone_resv(MEM_ZONE_STANDARD, start, end);
+}
+
+void 
+pm_release(physptr_t start, physptr_t end)
+{
+    size_t zone = pm_zone_for(start);
+    size_t limit = pm_zone_bound_upper(zone);
+
+    if(end > limit) {
+        pm_release(limit, end);
+        end = limit;
+    }
+    pm_zone_free(MEM_ZONE_STANDARD, start, end);
+}
+
+physptr_t
+pm_alloc(size_t pages)
+{
+    if(pm_zone_pages_free(MEM_ZONE_HIGHER) >= pages)
+        return pm_zone_alloc(MEM_ZONE_HIGHER, pages);
+    if(pm_zone_pages_free(MEM_ZONE_STANDARD) >= pages)
+        return pm_zone_alloc(MEM_ZONE_STANDARD, pages);
+    kpanic("Kernel ran out of physical memory!\n");
+}
diff --git a/mem/slab.c b/memory/slab.c
index 30bc23a..dc8aeda 100644
--- a/mem/slab.c
+++ b/memory/slab.c
@@ -1,33 +1,10 @@
 #include "slab.h"
+#include "bump.h"
 #include "memory.h"
-#include "lib/format.h"
-#include "lib/string.h"
-#include "lib/jove.h"
-#include "io/log.h"
-
-extern void *_kernel_end;
-
-static uintptr_t s_addr_next_free;
-
-#define GENERIC_CACHEC 8
-static struct SlabCache s_generic_caches[GENERIC_CACHEC];
-
-static uintptr_t
-s_next_free(size_t width)
-{
-    uintptr_t ret = s_addr_next_free;
-    s_addr_next_free += width;
-    mem_ensure_range(
-            ret,
-            s_addr_next_free,
-            (page_flags_t) { 
-                .present = true,
-                .writeable = true,
-                .useraccess = false,
-                .executable = false
-            });
-    return ret;
-}
+#include "string.h"
+#include "jove.h"
+#include "print.h"
+#include "klib/format.h"
 
 static int
 s_get_free_listw(size_t slabw, size_t objw)
@@ -41,27 +18,28 @@ s_get_free_listw(size_t slabw, size_t objw)
     return freelistc;
 }
 
-static struct SlabDescriptor
-*s_slab_new(struct SlabCache *cache, struct SlabDescriptor *last)
+static slab_t
+*s_slab_new(slab_cache_t *cache, slab_t *last)
 {
     size_t slab_width = (cache->slab_pages << PAGE_SHIFT);
-    uintptr_t descr_base = s_next_free(slab_width);
-    struct SlabDescriptor *descr = (struct SlabDescriptor*)descr_base;
+    uintptr_t descr_base = (uintptr_t)bump_alloc(slab_width);
+    slab_t *descr = (slab_t*)descr_base;
 
     size_t free_listc = s_get_free_listw(
-            slab_width - sizeof(struct SlabDescriptor),
+            slab_width - sizeof(slab_t),
             cache->obj_size);
-    size_t descriptor_width = sizeof(struct SlabDescriptor)
+    size_t descriptor_width = sizeof(slab_t)
         + (free_listc * sizeof(uintptr_t));
     uintptr_t obj_base = descr_base + descriptor_width;
 
     if(free_listc < 8) {
-        free_listc = ((slab_width - sizeof(struct SlabDescriptor)) / cache->obj_size);
-        descr = mem_alloc(sizeof(struct SlabDescriptor) + (free_listc * sizeof(uintptr_t)));
+        free_listc = ((slab_width - sizeof(slab_t)) / cache->obj_size);
+        descr = kmalloc(sizeof(slab_t) + (free_listc * sizeof(uintptr_t)));
         obj_base = descr_base;
     }
+    cache->obj_capacity += free_listc;
 
-    *descr = (struct SlabDescriptor) {
+    *descr = (slab_t) {
         .prev = last,
         .next = (last == NULL ? NULL : last->next),
         .slab_base = (void*)descr_base,
@@ -77,11 +55,11 @@ static struct SlabDescriptor
 }
 
 void
-mem_slabcache_new(struct SlabCache *cache, char *name, size_t objsize)
+slabcache_new(slab_cache_t *cache, char *name, size_t objsize)
 {
     if(objsize % 8 > 0) objsize += (8 - (objsize % 8));
     size_t pages = objsize > 512 ? (objsize >> 9) : 1;
-    *cache = (struct SlabCache){
+    *cache = (slab_cache_t){
         .obj_size = objsize,
         .slab_pages = pages,
         .list_free = NULL,
@@ -97,10 +75,10 @@ mem_slabcache_new(struct SlabCache *cache, char *name, size_t objsize)
 }
 
 void*
-mem_slab_alloc(struct SlabCache *cache)
+slab_alloc(slab_cache_t *cache)
 {
     // Get a free slab
-    struct SlabDescriptor *slab = NULL;
+    slab_t *slab = NULL;
     if(cache->list_partial != NULL) slab = cache->list_partial;
     if(slab == NULL && cache->list_free != NULL) {
         slab = cache->list_free;
@@ -121,11 +99,11 @@ mem_slab_alloc(struct SlabCache *cache)
 }
 
 void
-mem_slab_free(struct SlabCache *cache, void *ptr)
+slab_free(slab_cache_t *cache, void *ptr)
 {
     uintptr_t addr = (uintptr_t)ptr;
     //Look for the pointer in the bounds of every slab
-    for(struct SlabDescriptor *slab = cache->list_full; 
+    for(slab_t *slab = cache->list_full; 
             slab != NULL; slab = slab->next)
     {
         uintptr_t base = (uintptr_t)slab->obj_base;
@@ -145,7 +123,7 @@ mem_slab_free(struct SlabCache *cache, void *ptr)
         cache->list_partial = slab;
         return;
     }
-    for(struct SlabDescriptor *slab = cache->list_partial; 
+    for(slab_t *slab = cache->list_partial; 
             slab != NULL; slab = slab->next)
     {
         uintptr_t base = (uintptr_t)slab->obj_base;
@@ -160,7 +138,7 @@ mem_slab_free(struct SlabCache *cache, void *ptr)
         slab->free_index++;
         slab->free[slab->free_index] = addr;
 
-        if(slab->free_index == (slab->free_count - 1)) {
+        if(slab->free_index == ((int)slab->free_count - 1)) {
             cache->list_partial = slab->next;
             slab->next = cache->list_free;
             cache->list_free = slab;
@@ -168,42 +146,3 @@ mem_slab_free(struct SlabCache *cache, void *ptr)
         return;
     }
 }
-
-void*
-mem_alloc(size_t width)
-{
-    size_t width_log2 = (__builtin_clz(width) ^ 31) + 1;
-    if(width_log2 < 6) width_log2 = 6;
-    width_log2 -= 6;
-    if(width_log2 >= GENERIC_CACHEC) {
-        klogf("Allocation size %i too big for generic caches!\n", width);
-        return NULL;
-    }
-
-    struct SlabCache *generic_cache = &s_generic_caches[width_log2];
-    return mem_slab_alloc(generic_cache);
-}
-
-void
-mem_free(void *ptr)
-{
-    for(int i = 0; i < GENERIC_CACHEC; i++) {
-        mem_slab_free(&s_generic_caches[i], ptr);
-    }
-}
-
-void
-mem_slab_setup(void)
-{
-    s_addr_next_free = (uintptr_t)&_kernel_end;
-    s_addr_next_free = ((s_addr_next_free >> 12) + 1) << 12;
-    s_get_free_listw(PAGE_SIZE - sizeof(struct SlabDescriptor), 32);
-
-    for(int i = 0; i < GENERIC_CACHEC; i++)
-    {
-        size_t objsize = 1 << (i + 6);
-        char slab_name[SLABCACHE_NAME_LIMIT];
-        sfmt(slab_name, SLABCACHE_NAME_LIMIT, "generic_%i", 1 << (i + 6));
-        mem_slabcache_new(&s_generic_caches[i], slab_name, objsize);
-    }
-}
diff --git a/mem/zone.c b/memory/zone.c
index 42a056e..4201cee 100644
--- a/mem/zone.c
+++ b/memory/zone.c
@@ -1,10 +1,9 @@
 #include "zone.h"
+#include "boot.h"
 #include "memory.h"
-#include "boot/boot.h"
-#include "lib/string.h"
-#include "lib/jove.h"
-#include "sys/errno.h"
-#include "io/log.h"
+#include "jove.h"
+#include "string.h"
+#include "print.h"
 
 #define MEM_ZONE_STANDARD_PAGES  (MEM_ZONE_STANDARD_LIMIT >> PAGE_SHIFT)
 
@@ -37,7 +36,7 @@ static struct PhysicalMemoryZone s_zones[MEM_ZONE_COUNT] =
 };
 
 int
-mem_zone_for(uintptr_t addr)
+pm_zone_for(uintptr_t addr)
 {
     addr &= ~PAGE_MASK;
     for(size_t zonei = 0; zonei < MEM_ZONE_COUNT; zonei++)
@@ -45,25 +44,25 @@ mem_zone_for(uintptr_t addr)
         struct PhysicalMemoryZone *pmz = &s_zones[zonei];
         if(addr >= pmz->base && addr < pmz->limit) return zonei;
     }
-    return -ENOTFOUND;
+    return -1;
 }
 
 uintptr_t 
-mem_zone_bound_lower(size_t zone)
+pm_zone_bound_lower(size_t zone)
 {
     if(zone >= MEM_ZONE_COUNT) return 0;
     return s_zones[zone].base;
 }
 
 uintptr_t 
-mem_zone_bound_upper(size_t zone)
+pm_zone_bound_upper(size_t zone)
 {
     if(zone >= MEM_ZONE_COUNT) return 0;
     return s_zones[zone].limit;
 }
 
 size_t
-mem_zone_pages_free(size_t zone)
+pm_zone_pages_free(size_t zone)
 {
     if(zone >= MEM_ZONE_COUNT) return 0;
     return s_zones[zone].freemap.free;
@@ -82,9 +81,9 @@ _zone_free(struct PhysicalMemoryZone *zone, uintptr_t base, uintptr_t limit)
 }
 
 int
-mem_zone_resv(size_t zone, uintptr_t base, uintptr_t limit)
+pm_zone_resv(size_t zone, uintptr_t base, uintptr_t limit)
 {
-    if(zone >= MEM_ZONE_COUNT) return -EINVAL;
+    assert(zone < MEM_ZONE_COUNT);
 
     size_t base_off = base % PAGE_SIZE;
 
@@ -95,9 +94,9 @@ mem_zone_resv(size_t zone, uintptr_t base, uintptr_t limit)
 }
 
 int
-mem_zone_free(size_t zone, uintptr_t base, uintptr_t limit)
+pm_zone_free(size_t zone, uintptr_t base, uintptr_t limit)
 {
-    if(zone >= MEM_ZONE_COUNT) return -EINVAL;
+    assert(zone < MEM_ZONE_COUNT);
 
     size_t base_off = base % PAGE_SIZE;
 
@@ -108,7 +107,7 @@ mem_zone_free(size_t zone, uintptr_t base, uintptr_t limit)
 }
 
 uintptr_t
-mem_zone_alloc(size_t zone, size_t pages)
+pm_zone_alloc(size_t zone, size_t pages)
 {
     if(zone >= MEM_ZONE_COUNT) return 0;
 
@@ -122,7 +121,7 @@ mem_zone_alloc(size_t zone, size_t pages)
 }
 
 void
-mem_zone_setup_standard(void)
+pm_zone_setup(void)
 {
     struct PhysicalMemoryZone *standard_zone = &s_zones[MEM_ZONE_STANDARD];
     uintmax_t *map_block_layer_base = s_zone_standard_freemap_blocks_flat;
@@ -135,12 +134,12 @@ mem_zone_setup_standard(void)
 
     for(int i = 0; i < boot_memorymap.count; i++) {
         struct MemoryMapEntry *entry = &boot_memorymap.entries[i];
-        klogf("%2i\t%#016X -> %#016X (%i)\n",
+        kdbgf("%2i\t%#016X -> %#016X (%i)\n",
                 i, entry->base, entry->base + entry->length, entry->usable);
         if(entry->base > MEM_ZONE_STANDARD_LIMIT) continue;
         size_t limit = entry->base + entry->length;
         if(limit > MEM_ZONE_STANDARD_LIMIT) limit = MEM_ZONE_STANDARD_LIMIT;
         if(entry->usable)
-            mem_zone_free(MEM_ZONE_STANDARD, entry->base, limit);
+            pm_zone_free(MEM_ZONE_STANDARD, entry->base, limit);
     }
 }
diff --git a/print.c b/print.c
new file mode 100644
index 0000000..dc5597b
--- /dev/null
+++ b/print.c
@@ -0,0 +1,40 @@
+#include "print.h"
+#include "jove.h"
+#include "string.h"
+#include "device/serial.h"
+#include "klib/format.h"
+#include "klib/spinlock.h"
+
+static spinlock_t s_print_lock;
+static char s_print_buffer[PRINT_BUFFERW];
+
+static char *s_print_level_str[PRINT_ERROR + 1] = {
+    "[D] %s/%s:%i | ",
+    "[I] ",
+    "[W] %s/%s:%i | ",
+    "[!!E!!] %s/%s:%i | "
+};
+
+void 
+_plogvf(const char *file, const char *func, int line, int lvl, const char *fmt, va_list ap)
+{
+    spinlock_acquire(s_print_lock);
+
+    char *buf = sfmt(s_print_buffer, PRINT_BUFFERW, s_print_level_str[lvl],
+            file, func, line);
+    size_t prew = strlen(buf);
+
+    svfmt(&buf[prew], PRINT_BUFFERW - 128, fmt, ap);
+    serial_write(&COM1, buf, strlen(buf));
+
+    spinlock_release(s_print_lock);
+}
+
+void 
+_plogf(const char *file, const char *func, int line, int lvl, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    _plogvf(file, func, line, lvl, fmt, ap);
+    va_end(ap);
+}
diff --git a/sys/errno.h b/sys/errno.h
deleted file mode 100644
index 8d0c980..0000000
--- a/sys/errno.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef _SYS_ERRNO_H
-#define _SYS_ERRNO_H 1
-
-#define ENOPERM 1
-#define EFAULT 2
-#define EINVAL 3
-#define ENOSYS 4
-#define ENOTFOUND 5
-
-#endif
diff --git a/sys/permission.h b/sys/permission.h
deleted file mode 100644
index 08bb765..0000000
--- a/sys/permission.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef _SYS_PERMISSION_H
-#define _SYS_PERMISSION_H 1
-
-#define PERM_MEM_PHYS_RESV 1 /* Reserve physical memory. */
-#define PERM_MEM_PHYS_FREE 2 /* Free physical memory. */
-#define PERM_MEM_PHYS_ALLOC 4 /* Allocate physical memory. */
-
-#define PERM_MEM_VIRT_PD 8 /* Work on any PD. */
-#define PERM_MEM_VIRT_MAP 0x10 /* Map physical memory to virtual memory. */
-
-#endif
diff --git a/sys/syscall.h b/sys/syscall.h
deleted file mode 100644
index d8b64bb..0000000
--- a/sys/syscall.h
+++ /dev/null
@@ -1,69 +0,0 @@
-#ifndef _SYS_SYSCALL_H
-#define _SYS_SYSCALL_H 1
-
-#include <stdint.h>
-#include <stddef.h>
-#include "types.h"
-
-typedef struct syscall {
-    int id;
-} syscall_t;
-
-struct syscall_log {
-    syscall_t syscall;
-    const char *message;
-};
-
-struct syscall_mem_phys_range_op {
-    syscall_t syscall;
-    uintptr_t base;
-    uintptr_t limit;
-};
-
-struct syscall_mem_phys_alloc {
-    syscall_t syscall;
-    size_t npages;
-    uintptr_t *result;
-};
-
-struct syscall_mem_virt_mapping {
-    syscall_t syscall;
-    linear_address_t addr;
-    page_mapping_t *result;
-};
-
-struct syscall_mem_virt_map {
-    syscall_t syscall;
-    linear_address_t addr;
-    page_mapping_t map;
-};
-
-struct syscall_mem_virt_alloc {
-    syscall_t syscall;
-    linear_address_t from;
-    uintptr_t to;
-    page_flags_t flg;
-};
-
-enum
-{
-    SYSCALL_LOG = 0,
-    SYSCALL_TID,
-
-    SYSCALL_MEM_PHYS_RESV,
-    SYSCALL_MEM_PHYS_FREE,
-    SYSCALL_MEM_PHYS_ALLOC,
-
-    SYSCALL_MEM_VIRT_MAPPING,
-    SYSCALL_MEM_VIRT_MAP,
-    SYSCALL_MEM_VIRT_ALLOC,
-
-    SYSCALL_COUNT
-};
-
-#define _SYSCALL(data) \
-    intmax_t ax; \
-    __asm__ volatile("movq %0, %%rdi\nsyscall": "=a"(ax): "r"(data): "memory"); \
-    return ax
-
-#endif
diff --git a/sys/types.h b/sys/types.h
deleted file mode 100644
index 0a519c5..0000000
--- a/sys/types.h
+++ /dev/null
@@ -1,32 +0,0 @@
-#ifndef _SYS_TYPES_H
-#define _SYS_TYPES_H 1
-
-#include <stdint.h>
-#include <stddef.h>
-#include <stdbool.h>
-
-typedef intmax_t tid_t;
-
-typedef struct {
-    intmax_t tid;
-    uintmax_t addr;
-} linear_address_t;
-
-typedef uintptr_t physptr_t;
-
-typedef struct page_flags
-{
-    bool present;
-    bool writeable;
-    bool useraccess;
-    bool executable;
-} page_flags_t;
-
-typedef struct page_mapping
-{
-    physptr_t phys;
-    page_flags_t pf;
-} page_mapping_t;
-
-
-#endif
diff --git a/syscall/dbg_log.c b/syscall/dbg_log.c
new file mode 100644
index 0000000..9055498
--- /dev/null
+++ b/syscall/dbg_log.c
@@ -0,0 +1,19 @@
+#include "handler.h"
+#include "print.h"
+#include "umode_vma.h"
+#include "api/errno.h"
+
+int
+_handler_dbg_log(struct sc_dbg_log *u_sc)
+{
+    struct sc_dbg_log sc;
+    if(user_vma_read(&sc, u_sc, sizeof(struct sc_dbg_log)) != 0)
+        return -EFAIL;
+
+    char buf[sc.w];
+    if(user_vma_read(buf, sc.s, sc.w) != 0)
+        return -EFAIL;
+
+    klogf("%s", buf);
+    return 0;
+}
diff --git a/syscall/exit.c b/syscall/exit.c
new file mode 100644
index 0000000..307ea7a
--- /dev/null
+++ b/syscall/exit.c
@@ -0,0 +1,17 @@
+#include "api/syscall.h"
+#include "api/errno.h"
+#include "umode_vma.h"
+#include "arch/processor.h"
+#include "handler.h"
+
+int
+_handler_exit(struct sc_exit *sc)
+{
+    int exit_code = 0;
+    if(user_vma_read(&exit_code, &sc->exit_code, sizeof(int)) != 0)
+        return -EFAIL;
+
+    tcb_t *tcb = tcb_current();
+    tcb_kill(tcb, exit_code);
+    return 0;
+}
diff --git a/syscall/handler.c b/syscall/handler.c
new file mode 100644
index 0000000..5cafdc6
--- /dev/null
+++ b/syscall/handler.c
@@ -0,0 +1,23 @@
+#include "handler.h"
+#include "print.h"
+#include "umode_vma.h"
+#include "api/errno.h"
+
+static void *s_handlers[] = {
+    (void*)_handler_dbg_log,
+    (void*)_handler_exit
+};
+static size_t s_handlers_size = sizeof(s_handlers);
+
+int
+_syscall_handler(void *data)
+{
+    uintmax_t req_id = 0;
+    if(user_vma_read(&req_id, data, sizeof(uintmax_t)) != 0)
+        return -EFAIL;
+
+    if(req_id >= s_handlers_size) return -1;
+    int (*handle)(void*) = (int (*)(void*))s_handlers[req_id];
+    kdbgf("syscall id %i handle %p\n", req_id, handle);
+    return handle(data);
+}
diff --git a/syscall/handler.h b/syscall/handler.h
new file mode 100644
index 0000000..f746dcc
--- /dev/null
+++ b/syscall/handler.h
@@ -0,0 +1,19 @@
+#ifndef _JOVE_SYSCALL_HANDLER_H
+#define _JOVE_SYSCALL_HANDLER_H 1
+
+#include "api/syscall.h"
+#include "memory.h"
+
+int _syscall_handler(void *data);
+
+#define CHECKPTR(p) { \
+    page_mapping_t mapping = vm_mapping_get((uintptr_t)p); \
+    if(mapping.phys == 0 || /* Mapping must not map to NULL phys page. */ \
+       mapping.pf.present == 0 || /* Mapping must be present. */\
+       mapping.pf.useraccess == 0 /* Mapping must be useraccess. */) \
+    return -1; }
+
+int _handler_dbg_log(struct sc_dbg_log *sc);
+int _handler_exit(struct sc_exit *sc);
+
+#endif
diff --git a/task/exrtab.c b/task/exrtab.c
new file mode 100644
index 0000000..82b9e29
--- /dev/null
+++ b/task/exrtab.c
@@ -0,0 +1,19 @@
+#include "arch/processor.h"
+#include "assert.h"
+
+void
+_exrtab_push(void *v)
+{
+    processor_t *proc = processor_current();
+    proc->exrtab[proc->ert_i++] = (uintptr_t)v;
+}
+
+void*
+_exrtab_pop(void)
+{
+    processor_t *proc = processor_current();
+    
+    assert(proc->ert_i != 0);
+    uintptr_t r = proc->exrtab[--proc->ert_i];
+    return (void*)r;
+}
diff --git a/task/init.c b/task/init.c
new file mode 100644
index 0000000..c4c8bad
--- /dev/null
+++ b/task/init.c
@@ -0,0 +1,22 @@
+#include "commandline.h"
+#include "jove.h"
+#include "initrd.h"
+#include "tasking.h"
+#include "arch/elf.h"
+
+__attribute__((noreturn)) void
+kinit(void)
+{
+    const char *init_filepath = cmdline_get("init");
+    if(init_filepath == NULL)
+        kpanic("init filepath not found in kernel commandline\n");
+
+    initrd_file_t *init_file = ird_getfile(init_filepath);
+    if(init_file == NULL)
+        kpanic("init file not found in initrd [filepath=\"%s\"]\n", init_filepath);
+
+    uintptr_t ip = elf_load(init_file->data, init_file->size);
+
+    kexec((void*)ip, 0, NULL, 0, NULL);
+    kpanic("Reached end of kinit\n");
+}
diff --git a/task/stack.c b/task/stack.c
new file mode 100644
index 0000000..396ab3e
--- /dev/null
+++ b/task/stack.c
@@ -0,0 +1,14 @@
+#include "tasking.h"
+#include "string.h"
+#include "assert.h"
+
+void 
+tcb_stack_push(tcb_t *tcb, void *data, size_t len)
+{
+    assert(tcb != NULL);
+    void *spo = (void*)(tcb->ksp - len);
+    assert(spo >= tcb->stack);
+
+    memcpy(spo, data, len);
+    tcb->ksp = (uintptr_t)spo;
+}
diff --git a/task/tasking.c b/task/tasking.c
new file mode 100644
index 0000000..ee57a13
--- /dev/null
+++ b/task/tasking.c
@@ -0,0 +1,45 @@
+#include "tasking.h"
+#include "slab.h"
+#include "klib/rbtree.h"
+#include "arch/processor.h"
+
+rbtree_t s_tcbs;
+tcbid_t s_tcb_nextid = 0;
+slab_cache_t s_kstack_slab;
+
+void
+tasking_setup(void)
+{
+    rbtree_new(&s_tcbs, tcb_t);
+    slabcache_new(&s_kstack_slab, "kernel stack", KERNEL_STACKW);
+
+    extern void kernel_stage2(void);
+    tcb_t *init_tcb = tcb_new((void*)kernel_stage2, pd_current());
+
+    tcb_switch(init_tcb);
+}
+
+tcb_t*
+tcb_new(void *ip, page_directory_t *pd)
+{
+    void *stack = slab_alloc(&s_kstack_slab);
+    tcb_t *tcb = rbtree_reserve(&s_tcbs, s_tcb_nextid);
+    *tcb = (tcb_t) {
+        .id = s_tcb_nextid++,
+        .stack = stack,
+        .ksp = ((uintptr_t)stack) + (KERNEL_STACKW - 1),
+        .pd = pd,
+        .state = TCB_RUNNING
+    };
+
+    tcb_prepare(tcb, ip);
+    return tcb;
+}
+
+void 
+tcb_kill(tcb_t *tcb, int code)
+{
+    if(tcb->id == 0) kpanic("init thread killed!\n");
+    tcb->state = TCB_DEAD;
+    tcb->exit_code = code;
+}
diff --git a/task/umode_vma.c b/task/umode_vma.c
new file mode 100644
index 0000000..880e047
--- /dev/null
+++ b/task/umode_vma.c
@@ -0,0 +1,37 @@
+#include "umode_vma.h"
+#include "arch/processor.h"
+#include "api/errno.h"
+#include "print.h"
+
+__attribute__((naked))
+int
+_umode_vma_fail(void)
+{
+    __asm__ volatile(" \
+    movq %%rbp, %%rsp; \
+    popq %%rbp; \
+    mov $1, %%eax; \
+    retq":::);
+}
+
+int
+user_vma_read(void *dest, const void *src, size_t w)
+{
+    if((uintptr_t)src > USERLAND_MEMORY_LIMIT) return -EACCESS;
+
+    _exrtab_push((void*)_umode_vma_fail);
+    for(size_t i = 0; i < w; i++) ((char*)dest)[i] = ((const char*)src)[i];
+    _exrtab_pop();
+    return 0;
+}
+
+int
+user_vma_write(void *dest, const void *src, size_t w)
+{
+    if((uintptr_t)dest > USERLAND_MEMORY_LIMIT) return -EACCESS;
+    
+    _exrtab_push((void*)_umode_vma_fail);
+    for(size_t i = 0; i < w; i++) ((char*)dest)[i] = ((const char*)src)[i];
+    _exrtab_pop();
+    return 0;
+}
diff --git a/usr/elf.h b/usr/elf.h
deleted file mode 100644
index d805e55..0000000
--- a/usr/elf.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef JOVE_USER_ELF_H
-#define JOVE_USER_ELF_H 1
-
-#include <stddef.h>
-
-/**Load an ELF file into usermode memory.
- * @param data pointer to ELF file data buffer
- * @param len length of ELF file data buffer
- * @return entry point for loaded ELF exec*/
-void *elf_load(const void *data, size_t len);
-
-#endif
diff --git a/usr/syscall.c b/usr/syscall.c
deleted file mode 100644
index fbc5fe7..0000000
--- a/usr/syscall.c
+++ /dev/null
@@ -1,104 +0,0 @@
-#include "syscall.h"
-#include "sys/errno.h"
-#include "sys/permission.h"
-#include "usr/tasking.h"
-#include "mem/memory.h"
-#include "io/log.h"
-
-#define ENSURE_ADDR(ptr) \
-    if(!mem_check_ptr(ptr)) { klogf("User passed bad address %#016X\n", ptr); return -EFAULT; }
-
-#define ENSURE_PERM(p) \
-    if(!(task_current->perm & p)) return -ENOPERM
-
-#define PD_FOR_LINEAR_ADDRESS(addr) current_page_directory; \
-    if(addr.tid == -1) addr.tid = task_current->id; \
-    if(addr.tid != task_current->id) { \
-        ENSURE_PERM(PERM_MEM_VIRT_PD); \
-        struct Task *task = task_get(addr.tid); \
-        if(task == NULL) return -EFAULT; \
-        pd = task->pd; \
-    }
-
-int _syscall_handler_log(struct syscall_log *req)
-{
-    ENSURE_ADDR(req->message);
-    klogf("%s", req->message);
-    return 0;
-}
-
-intmax_t _syscall_handler_tid(syscall_t *req)
-{
-    return task_current->id;
-}
-
-int _syscall_handler_mem_phys_resv(struct syscall_mem_phys_range_op *req)
-{
-    ENSURE_PERM(PERM_MEM_PHYS_RESV);
-    mem_phys_reserve(req->base, req->limit);
-    return 0;
-}
-
-int _syscall_handler_mem_phys_free(struct syscall_mem_phys_range_op *req)
-{
-    ENSURE_PERM(PERM_MEM_PHYS_FREE);
-    mem_phys_release(req->base, req->limit);
-    return 0;
-}
-
-int _syscall_handler_mem_phys_alloc(struct syscall_mem_phys_alloc *req)
-{
-    ENSURE_ADDR(req->result);
-    ENSURE_PERM(PERM_MEM_PHYS_ALLOC);
-    *req->result = mem_phys_alloc(req->npages);
-    return 0;
-}
-
-int _syscall_handler_mem_virt_mapping(struct syscall_mem_virt_mapping *req)
-{
-    ENSURE_ADDR(req->result);
-    ENSURE_PERM(PERM_MEM_VIRT_MAP);
-    page_directory_t *pd = PD_FOR_LINEAR_ADDRESS(req->addr);
-    *req->result = mem_get_mapping_as(pd, req->addr.addr);
-    return 0;
-}
-
-int _syscall_handler_mem_virt_map(struct syscall_mem_virt_map *req)
-{
-    ENSURE_PERM(PERM_MEM_VIRT_MAP);
-    page_directory_t *pd = PD_FOR_LINEAR_ADDRESS(req->addr);
-    mem_set_mapping_as(pd, req->map, req->addr.addr);
-    return 0;
-}
-
-int _syscall_handler_mem_virt_alloc(struct syscall_mem_virt_alloc *req)
-{
-    ENSURE_PERM(PERM_MEM_VIRT_MAP);
-    ENSURE_PERM(PERM_MEM_PHYS_ALLOC);
-    page_directory_t *pd = PD_FOR_LINEAR_ADDRESS(req->from);
-    mem_ensure_range_as(pd, req->from.addr, req->to, req->flg);
-    return 0;
-}
-
-void *_syscall_handlers[SYSCALL_COUNT] = {
-    _syscall_handler_log,
-    _syscall_handler_tid,
-
-    _syscall_handler_mem_phys_resv,
-    _syscall_handler_mem_phys_free,
-    _syscall_handler_mem_phys_alloc,
-
-    _syscall_handler_mem_virt_mapping,
-    _syscall_handler_mem_virt_map,
-    _syscall_handler_mem_virt_alloc,
-};
-
-int
-syscall_handler(syscall_t *req)
-{
-    ENSURE_ADDR(req);
-    if(req->id >= SYSCALL_COUNT) return -ENOSYS;
-
-    ENSURE_ADDR(_syscall_handlers[req->id]);
-    return ((syscall_handler_t)(_syscall_handlers[req->id]))(req);
-}
diff --git a/usr/syscall.h b/usr/syscall.h
deleted file mode 100644
index 5cc82b8..0000000
--- a/usr/syscall.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef JOVE_USER_SYSCALL_H
-#define JOVE_USER_SYSCALL_H 1
-
-#include "sys/syscall.h"
-
-typedef int (*syscall_handler_t)(syscall_t*);
-
-int _syscall_handler_log(struct syscall_log *req);
-intmax_t _syscall_handler_tid(syscall_t *req);
-
-#endif
diff --git a/usr/tasking.c b/usr/tasking.c
deleted file mode 100644
index cb4df25..0000000
--- a/usr/tasking.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include "tasking.h"
-
-void
-task_perm_release(struct Task *task, size_t mask)
-{
-    task->perm &= ~mask;
-}
diff --git a/usr/tasking.h b/usr/tasking.h
deleted file mode 100644
index 4b11999..0000000
--- a/usr/tasking.h
+++ /dev/null
@@ -1,28 +0,0 @@
-#ifndef JOVE_TASKING_H
-#define JOVE_TASKING_H 1
-
-#include <stddef.h>
-#include <stdint.h>
-#include "sys/types.h"
-#include "mem/memory.h"
-
-struct Task
-{
-    struct Task *next;
-    tid_t id;
-    uintptr_t kbp;
-    size_t perm;
-
-    page_directory_t *pd;
-};
-
-extern struct Task *task_current;
-
-void tasking_setup(void);
-
-struct Task *task_new(struct Task *parent);
-struct Task *task_get(tid_t id);
-
-void task_perm_release(struct Task *task, size_t mask);
-
-#endif
diff --git a/usr/umode.c b/usr/umode.c
deleted file mode 100644
index 1105d9e..0000000
--- a/usr/umode.c
+++ /dev/null
@@ -1,39 +0,0 @@
-#include "umode.h"
-#include "elf.h"
-#include "boot/cmdline.h"
-#include "lib/jove.h"
-#include "ird/initrd.h"
-#include "mem/memory.h"
-
-void
-umode_setup(void)
-{
-    extern void syscall_setup_syscall(void);
-    syscall_setup_syscall();
-
-    const char *init_path = cmdline_get("init");
-    if(init_path == NULL)
-        kpanic("Missing path to init ELF file / binary\n");
-
-    struct InitrdFile *init_file = ird_getfile(init_path);
-    if(init_file == NULL)
-        kpanic("Missing init file %s in initrd\n", init_path);
-
-    void (*entry_point)(void) = elf_load(init_file->data, init_file->size);
-    if(entry_point == NULL)
-        kpanic("Init file %s is incorrectly formatted (want ELF64)\n", init_path);
-
-    void *user_stack = (void*)(0x00007FFFFFFFFFFF);
-    mem_ensure_range(
-            (uintptr_t)user_stack & ~0xFFF,
-            (uintptr_t)user_stack,
-            (page_flags_t) {
-                .present = true,
-                .writeable = true,
-                .useraccess = true,
-                .executable = false
-            });
-
-    klogf("User entry point %#016X\n", entry_point);
-    umode_enter(entry_point, user_stack);
-}
diff --git a/usr/umode.h b/usr/umode.h
deleted file mode 100644
index 2755abe..0000000
--- a/usr/umode.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef JOVE_UMODE_H
-#define JOVE_UMODE_H 1
-
-void umode_setup(void);
-
-void umode_enter(void (*entry)(void), void *stack);
-
-#endif