homebrewfilter/source/BootHomebrew/elfloader.c
2011-09-25 19:47:02 +02:00

89 lines
3.0 KiB
C

/*
* Copyright (c) 2001 William L. Pitts
* Modifications (c) 2004 Felix Domke
* All rights reserved.
*
* Redistribution and use in source and binary forms are freely
* permitted provided that the above copyright notice and this
* paragraph and the following disclaimer are duplicated in all
* such forms.
*
* This software is provided "AS IS" and without any express or
* implied warranties, including, without limitation, the implied
* warranties of merchantability and fitness for a particular
* purpose.
*/
#include <stdio.h>
#include <string.h>
#include <gccore.h>
#include "elf_abi.h"
/* ======================================================================
* Determine if a valid ELF image exists at the given memory location.
* First looks at the ELF header magic field, the makes sure that it is
* executable and makes sure that it is for a PowerPC.
* ====================================================================== */
s32 valid_elf_image (void *addr) {
Elf32_Ehdr *ehdr; /* Elf header structure pointer */
ehdr = (Elf32_Ehdr *) addr;
if (!IS_ELF (*ehdr))
return 0;
if (ehdr->e_type != ET_EXEC)
return -1;
if (ehdr->e_machine != EM_PPC)
return -1;
return 1;
}
/* ======================================================================
* A very simple elf loader, assumes the image is valid, returns the
* entry point address.
* ====================================================================== */
u32 load_elf_image (void *addr)
{
Elf32_Ehdr *ehdr;
Elf32_Shdr *shdr;
u8 *strtab = 0;
u8 *image;
int i;
ehdr = (Elf32_Ehdr *) addr;
/* Find the section header string table for output info */
shdr = (Elf32_Shdr *) (addr + ehdr->e_shoff +
(ehdr->e_shstrndx * sizeof (Elf32_Shdr)));
if (shdr->sh_type == SHT_STRTAB)
strtab = (u8 *) (addr + shdr->sh_offset);
/* Load each appropriate section */
for (i = 0; i < ehdr->e_shnum; ++i) {
shdr = (Elf32_Shdr *) (addr + ehdr->e_shoff +
(i * sizeof (Elf32_Shdr)));
if (!(shdr->sh_flags & SHF_ALLOC)
|| shdr->sh_addr == 0 || shdr->sh_size == 0) {
continue;
}
shdr->sh_addr &= 0x3FFFFFFF;
shdr->sh_addr |= 0x80000000;
if (shdr->sh_type == SHT_NOBITS) {
memset ((void *) shdr->sh_addr, 0, shdr->sh_size);
} else {
image = (u8 *) addr + shdr->sh_offset;
memcpy ((void *) shdr->sh_addr,
(const void *) image,
shdr->sh_size);
}
DCFlushRangeNoSync ((void *) shdr->sh_addr, shdr->sh_size);
}
return (ehdr->e_entry & 0x3FFFFFFF) | 0x80000000;
}