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#include "proc/init.h"
#include "arch/x86_64/hal/msr.h"
#include "config.h"
#include "proc/process.h"
#include "jove.h"
#include "hal/obj.h"
#include "lib/string.h"
#include "sys/objdir.h"
#include "panic/panic.h"
#include "lib/printf.h"
#include "arch/x86_64/lib/elf.h"
#include "arch/x86_64/hal/paging.h"
#include "boot/cmdline.h"
#include "boot/initrd.h"
static int
elf_is_valid(struct elf_header *ehdr)
{
if(ehdr->e_ident[0] != EI_MAG0 ||
ehdr->e_ident[1] != EI_MAG1 ||
ehdr->e_ident[2] != EI_MAG2 ||
ehdr->e_ident[3] != EI_MAG3) {
kprintf("ELF: Magic does not match!\n");
return 0;
}
if(ehdr->e_ident[4] != EI_CLASS_64) {
kprintf("ELF: Class is not 64-bit!\n");
return 0;
}
if(ehdr->e_ident[5] != EI_DATA_LE) {
kprintf("ELF: Data is not little-endian!\n");
return 0;
}
if(ehdr->e_type != ET_EXEC) {
kprintf("ELF: Program is not standard executable type!\n");
return 0;
}
if(ehdr->e_machine != EM_x86_64) {
kprintf("ELF: Executable is not x86_64!\n");
return 0;
}
return 1;
}
void
init_setup(void)
{
//Get the init file data from the initrd.
const char *init_path = cmdline_getarg("init");
if(init_path == NULL) {
kpanic("Kernel commandline is missing 'init' arg.\n");
}
jove_owned_obj_t *initrd_obj = objdir_getlocal(_rootdir_obj, INIT_ROOTDIR_INITRD_I);
jove_owned_obj_t *init_obj = initrd_seek(initrd_obj, init_path);
if(init_obj == NULL) {
kpanic("init: Cannot find file '%s' in initrd.\n", init_path);
}
obj_release(initrd_obj);
void *init_data = initrd_file_data(init_obj);
obj_release(init_obj);
struct elf_header *init_ehdr = init_data;
if(init_ehdr == NULL) {
kpanic("init: Cannot get file data for file '%s': %i\n", init_path, errno);
}
if(!elf_is_valid(init_ehdr)) {
kpanic("init: Either passed file '%s' is not an ELF file or is not loadable.\n", init_path);
}
jove_owned_obj_t *init_pagedir = objdir_getlocal(_rootdir_obj, INIT_ROOTDIR_PAGEDIR_I);
page_t *pml4 = obj_deref(init_pagedir);
size_t last_base = 0;
//Load the init ELF
for(size_t i = 0; i < init_ehdr->e_phnum; i++) {
struct elf_phdr *phdr = init_data + init_ehdr->e_phoff + i * init_ehdr->e_phentsize;
if(phdr->p_type != PT_LOAD) continue;
kprintf("init: phdr %i flags %b\n", i, phdr->p_flags);
uintptr_t base = phdr->p_vaddr;
size_t limit = phdr->p_memsz;
if(last_base < base + limit) last_base = base + limit;
uintptr_t page_base = base & ~0xFFFULL;
size_t pages = (limit + 4095) / 4096;
for(size_t i = 0; i < pages; i++) {
uintptr_t page_virt = page_base + (i << 12);
int tblres = 0;
jove_owned_obj_t page_frame;
do {
page_frame = init_pop_alloc();
tblres = pagedir_map_table(pml4, obj_getvalue(&page_frame), page_virt);
}while(tblres == 0);
pagedir_map_frame(pml4, obj_getvalue(&page_frame), page_virt,
PAGE_WRITEABLE | PAGE_USER);
}
//Copy data from section if SHT_PROGBITS
memcpy((void*)phdr->p_vaddr, init_data + phdr->p_offset, phdr->p_memsz);
}
//Map the stack
size_t stack_base = 0x00007FFFFFFFF000;
int stack_mapres = 0;
for(size_t i = 0; i < INIT_STACK_PAGES; i++) {
uintptr_t page_virt = stack_base - (i << 12);
int tblres = 0;
jove_owned_obj_t page_frame;
do {
page_frame = init_pop_alloc();
tblres = pagedir_map_table(pml4, obj_getvalue(&page_frame), page_virt);
}while(!tblres);
pagedir_map_frame(pml4, obj_getvalue(&page_frame), page_virt,
PAGE_WRITEABLE | PAGE_USER | PAGE_XD);
}
//Map the syscall message.
last_base = (last_base + 0xFFF) & ~0xFFF;
jove_owned_obj_t message_frame = init_pop_alloc();
pagedir_map_frame(pml4, obj_getvalue(&message_frame), last_base,
PAGE_WRITEABLE | PAGE_USER | PAGE_XD);
extern struct init_payload _init_payload;
_init_payload.brk = last_base + 0x1000;
memcpy((void*)last_base, &_init_payload, sizeof(struct init_payload));
jove_owned_obj_t *message_obj = objdir_getlocal(_rootdir_obj, INIT_ROOTDIR_MESSAGE_I);
obj_settype(message_obj, JOVE_OBJ_MESSAGE);
obj_setvalue(message_obj, last_base | 1);
obj_release(message_obj);
obj_release(init_pagedir);
//Enable syscalls
extern void _syscall_entry(void);
msr_set_lstar(_syscall_entry);
obj_release(_rootdir_obj);
//Setup KSP for syscalls
uintptr_t usp = 0x00007FFFFFFFFFF8;
uintptr_t uip = init_ehdr->e_entry;
__asm__ volatile("movq %0, %%rsp; \
movq %1, %%rcx; \
movq %2, %%rdi; \
movq $0x202, %%r11; \
swapgs; \
sysretq"::
"r"(usp), "r"(uip), "m"(last_base): "memory");
}
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