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#include <kernel/system.h>
#include <kernel/fs/elf.h>
#include <kernel/lib/stdio.h>
#include <kernel/memory/alloc.h>
#include <kernel/lib/lib.h>
#include <kernel/memory/paging.h>
#include <kernel/fs/ext2.h>
#include <kernel/gdt/gdt.h>
int is_elf(elf_header_t *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;
}
void elf_load(char *path)
{
uint8_t *file = read_file(path);
if (!file) {
warn("File or directory not found: %s", file);
return;
}
elf_header_t *header = (elf_header_t *)file;
elf_program_header_t *program_header = (void *)header + header->phoff;
if (!is_elf(header)) {
warn("File not valid: %s", path);
return;
} else {
debug("File is valid: %s", path);
}
uint32_t eip = 0;
uint32_t seg_begin, seg_end;
for (int i = 0; i < header->phnum; i++) {
if (program_header->type == 1) {
seg_begin = program_header->vaddr;
seg_end = seg_begin + program_header->memsz;
for (uint32_t z = 0; z < seg_end - seg_begin; z += 4096)
paging_map((uint32_t)seg_begin + z, (uint32_t)seg_begin + z,
PT_PRESENT | PT_RW | PT_USED | PT_ALL_PRIV);
memcpy((void *)seg_begin, file + program_header->offset,
program_header->filesz);
memset((void *)(seg_begin + program_header->filesz), 0,
program_header->memsz - program_header->filesz);
// Code segment
if (program_header->flags == PF_X + PF_R + PF_W ||
program_header->flags == PF_X + PF_R) {
debug("Found code segment");
eip = header->entry + seg_begin;
}
}
program_header++;
};
// Just some testing, will be moved later
uint32_t sp;
asm("mov %%esp, %0" : "=rm"(sp));
set_kernel_stack(sp);
// paging_switch_directory(1);
uint32_t esp = paging_alloc_pages(0x1000);
asm("mov %0, %%esp" ::"r"(esp + 0x1000));
log("Jumping to usermode!");
asm volatile("\
cli; \
mov $0x23, %%ax; \
mov %%ax, %%ds; \
mov %%ax, %%es; \
mov %%ax, %%fs; \
mov %%ax, %%gs; \
mov %%esp, %%eax; \
pushl $0x23; \
pushl %%esp; \
pushf; \
push $0x1B; \
push %0; \
iret; \
"
:
: "r"(eip));
}
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