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#include <fs/elf.h>
#include <fs/ext2.h>
#include <gdt/gdt.h>
#include <io/io.h>
#include <lib/lib.h>
#include <lib/stdio.h>
#include <lib/stdlib.h>
#include <memory/alloc.h>
#include <memory/paging.h>
#include <stddef.h>
#include <stdint.h>
#include <system.h>
#include <tasks/process.h>
int elf_verify(struct elf_header *header)
{
if (header->ident[0] == ELF_MAG && header->ident[1] == 'E' && header->ident[2] == 'L' &&
header->ident[3] == 'F' && header->ident[4] == ELF_32 &&
header->ident[5] == ELF_LITTLE && header->ident[6] == ELF_CURRENT &&
header->machine == ELF_386 && (header->type == ET_REL || header->type == ET_EXEC)) {
return 1;
}
return 0;
}
struct process *elf_load(char *path)
{
log("ELF START");
u8 *file = read_file(path);
if (!file) {
warn("File or directory not found: %s", path);
return NULL;
}
struct elf_header *header = (struct elf_header *)file;
if (!elf_verify(header)) {
warn("File not valid: %s", path);
return NULL;
} else {
debug("File is valid: %s", path);
}
struct process *proc = process_make_new();
paging_switch_dir(proc->cr3);
u32 image_low = 0xFFFFFFFF;
u32 image_high = 0;
// Parse ELF
u32 i = 0;
u32 j = 0;
while (i < header->shentsize * header->shnum) {
struct elf_section_header *sh = (void *)((u32)header + (header->shoff + i));
if (sh->addr != 0) {
log("%x", sh->addr);
/* for (u32 j = 0; j < sh->size; j += PAGE_SIZE) { */
/* paging_frame_alloc(paging_get_page(sh->addr + j, proc->cr3)); */
/* invlpg(sh->addr + j); */
/* } */
while (j < sh->size) {
paging_frame_alloc(paging_get_page(sh->addr + j, proc->cr3));
invlpg(sh->addr + j);
j += 0x1000;
}
if (sh->type == 8)
// section is .bss
memset((void *)sh->addr, 0, sh->size);
else
memcpy((void *)sh->addr, (void *)((u32)header + sh->offset),
sh->size);
if (sh->addr < image_low)
image_low = sh->addr;
if (sh->addr + sh->size > image_high)
image_high = sh->addr + sh->size;
}
i += header->shentsize;
}
// Stack
struct page_table_entry *stack_page = paging_get_page(USER_STACK_LOW, proc->cr3);
paging_frame_alloc(stack_page);
stack_page->writable = 1;
invlpg(USER_STACK_LOW);
strcpy(proc->name, path);
proc->brk = image_high;
proc->regs.useresp = USER_STACK_HIGH;
proc->regs.ebp = proc->regs.useresp;
proc->regs.esp = proc->regs.useresp;
proc->regs.eip = header->entry;
debug("Loaded file");
return proc;
}
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