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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 is_elf(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)
{
u32 *prev_dir;
if (current_proc)
prev_dir = current_proc->cr3;
else
prev_dir = current_page_directory;
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;
struct elf_program_header *program_header = (void *)header + header->phoff;
if (!is_elf(header)) {
warn("File not valid: %s", path);
return NULL;
} else {
debug("File is valid: %s", path);
}
struct process *proc = process_make_new();
strcpy(proc->name, path);
proc->registers.eip = header->entry;
log("1");
paging_switch_directory(proc->cr3);
log("2");
u32 stk = (u32)malloc(PAGE_SIZE);
log("3");
proc->registers.useresp = 0x40000000 - (PAGE_SIZE / 2);
proc->registers.ebp = proc->registers.useresp;
proc->registers.esp = proc->registers.useresp;
paging_map(stk, 0x40000000 - PAGE_SIZE, PT_USER);
for (int i = 0; i < header->phnum; i++, program_header++) {
switch (program_header->type) {
case 0:
break;
case 1: {
u32 loc = (u32)malloc(PAGE_SIZE);
paging_map(loc, program_header->vaddr, PT_USER);
memcpy((void *)program_header->vaddr,
((void *)((u32)file) + program_header->offset),
program_header->filesz);
if (program_header->filesz > PAGE_SIZE)
panic("ELF binary section too large");
break;
}
default:
warn("Unknown header type");
}
}
paging_switch_directory(prev_dir);
return proc;
}
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