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// MIT License, Copyright (c) 2021 Marvin Borner
#include <elf.h>
#include <panic.h>
u32 elf_load(struct dev *dev, const char *path)
{
assert(dev->type == DEVICE_DISK);
struct elf_header header = { 0 };
s32 rd = dev->p.disk.fs.read(path, &header, 0, sizeof(header), dev);
if (rd < 0)
panic("File couldn't be found\n");
if (rd != sizeof(header))
panic("File too small\n");
// Valid?
u8 *magic = header.ident;
u8 valid_magic = magic[ELF_IDENT_MAG0] == ELF_MAG0 && magic[ELF_IDENT_MAG1] == ELF_MAG1 &&
magic[ELF_IDENT_MAG2] == ELF_MAG2 && magic[ELF_IDENT_MAG3] == ELF_MAG3 &&
magic[ELF_IDENT_CLASS] == ELF_IDENT_CLASS_32 &&
magic[ELF_IDENT_DATA] == ELF_IDENT_DATA_LSB;
if (!valid_magic || (header.type != ELF_ETYPE_REL && header.type != ELF_ETYPE_EXEC) ||
header.version != 1 || header.machine != ELF_MACHINE_386)
panic("File is not valid ELF\n");
// Loop through programs
for (u32 i = 0; i < header.phnum; i++) {
struct elf_program program = { 0 };
if (dev->p.disk.fs.read(path, &program, header.phoff + header.phentsize * i,
sizeof(program), dev) != sizeof(program))
panic("Couldn't read program\n");
if (program.type == ELF_PROGRAM_TYPE_INTERP)
panic("Program interpreters aren't supported\n");
if (program.vaddr == 0 || program.type != ELF_PROGRAM_TYPE_LOAD)
continue;
if ((u32)dev->p.disk.fs.read(path, (void *)program.vaddr, program.offset,
program.filesz, dev) != program.filesz)
panic("Couldn't load program\n");
}
// Find section string table
struct elf_section section_strings = { 0 };
if (dev->p.disk.fs.read(path, §ion_strings,
header.shoff + header.shentsize * header.shstrndx,
sizeof(section_strings), dev) != sizeof(section_strings))
panic("Couldn't find string section\n");
if (section_strings.type != ELF_SECTION_TYPE_STRTAB)
panic("Invalid string section\n");
return header.entry;
}
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