From 8de23ca36173cfdb3c609074496115ebd9045887 Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Sat, 26 Sep 2026 22:07:16 -0400
Subject: x86_64: make syscall_entry compliant to SYSTEM-V ABI

---
 arch/x86_64/hal/smp.c     |  2 +-
 arch/x86_64/sys/syscall.c | 15 ++++-----------
 arch/x86_64/sys/syscall.h |  2 +-
 boot/limine/memorymap.c   |  2 +-
 sys/syscall.c             |  4 ++++
 sys/syscall_objdir.c      |  1 +
 6 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/arch/x86_64/hal/smp.c b/arch/x86_64/hal/smp.c
index 473786d..f67ce0b 100644
--- a/arch/x86_64/hal/smp.c
+++ b/arch/x86_64/hal/smp.c
@@ -54,7 +54,7 @@ smp_init_bsp(void)
         obj_release(processor_objdir_obj);
     }
 
-    idt_init();
+    //idt_init();
     paging_pml4_init();
 }
 
diff --git a/arch/x86_64/sys/syscall.c b/arch/x86_64/sys/syscall.c
index a694674..7c5727f 100644
--- a/arch/x86_64/sys/syscall.c
+++ b/arch/x86_64/sys/syscall.c
@@ -26,35 +26,28 @@ _syscall_handle_arch(syscall_context_t *ctx)
 __attribute__((naked))
 void _syscall_entry(void)
 {
-    __asm__ volatile(" \
+    asm volatile(" \
                      swapgs; \
                      movq %%gs:%c[pcb], %%rax; \
                      movq %%rsp, %%rdx; \
                      movq %c[ksp](%%rax), %%rsp; \
-                     pushq %%rcx; \
                      pushq %%rdx; \
                      pushq %%r11; \
+                     pushq %%rcx; \
                      pushq %%rbp; \
                      callq syscall_handler; \
                      swapgs; \
-                     xorq %%r15, %%r15; \
-                     xorq %%r14, %%r14; \
-                     xorq %%r13, %%r13; \
-                     xorq %%r12, %%r12; \
                      xorq %%r10, %%r10; \
                      xorq %%r9, %%r9; \
                      xorq %%r8, %%r8; \
                      xorq %%rsi, %%rsi; \
                      xorq %%rdi, %%rdi; \
-                     xorq %%rbp, %%rbp; \
                      xorq %%rdx, %%rdx; \
-                     xorq %%rcx, %%rcx; \
-                     xorq %%rbx, %%rbx; \
                      popq %%rbp; \
+                     popq %%rcx; \
                      popq %%r11; \
                      popq %%rsp; \
-                     popq %%rcx; \
-                     sysretq;"
+                     sysretq"
                      ::
                      [pcb] "i"(offsetof(processor_t, pcb)),
                      [ksp] "i"(offsetof(pcb_t, ksp)));
diff --git a/arch/x86_64/sys/syscall.h b/arch/x86_64/sys/syscall.h
index 34f6a2a..32bf787 100644
--- a/arch/x86_64/sys/syscall.h
+++ b/arch/x86_64/sys/syscall.h
@@ -5,6 +5,6 @@
 
 int _syscall_handle_serial(syscall_context_t *ctx);
 
-#define SYSCALL_SERIAL_COM_WRITE 0
+#define SYSCALL_SERIAL_COM_WRITE 1
 
 #endif
diff --git a/boot/limine/memorymap.c b/boot/limine/memorymap.c
index a8841e2..98405fd 100644
--- a/boot/limine/memorymap.c
+++ b/boot/limine/memorymap.c
@@ -86,7 +86,7 @@ mem_setup_untyped(void)
                 }
 
                 size_t pages = hw_pages > 4095 ? 4095 : hw_pages;
-                klogf("%p : %p RESERVED\n", base, ((pages + 1) << 12));
+                //klogf("%p : %p RESERVED\n", base, ((pages + 1) << 12));
 
                 jove_owned_obj_t *hwmem_obj = obj_take(&s_hwmemory_objdir.entries[hwmem_i++]);
                 obj_settype(hwmem_obj, JOVE_OBJ_SHMEMORY);
diff --git a/sys/syscall.c b/sys/syscall.c
index 0da3475..31f9078 100644
--- a/sys/syscall.c
+++ b/sys/syscall.c
@@ -50,6 +50,10 @@ int
 _syscall_handle_switch(syscall_context_t *ctx)
 {
     uint8_t target_type = obj_gettype(ctx->target.obj);
+    if(target_type == JOVE_OBJ_NONE) {
+        klogf("Tried to call syscall on NULL object %P\n", ctx->header->path, ctx->header->pathlen);
+        return -EBADOBJ;
+    }
     if(target_type > 0x7F) {
         return _syscall_handle_arch(ctx);
     }
diff --git a/sys/syscall_objdir.c b/sys/syscall_objdir.c
index 5a6786d..b4d3800 100644
--- a/sys/syscall_objdir.c
+++ b/sys/syscall_objdir.c
@@ -15,6 +15,7 @@ s_syscall_objdir_objtype(
     CHECK_TOOSMALL(bytes_needed, payload_size, "Message is too small for payload.");
 
     uint16_t local_idx = *((uint16_t*)payload_data);
+
     if(local_idx > JOVE_OBJDIR_ENTRIES) {
         kprintf("%s: Object index is out of bounds (>= 512)\n", __func__);
         return EOOB;
-- 
cgit v1.2.3