grub/efiemu/i386/loadcore32.c

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/* i386 CPU-specific part of loadcore.c for 32-bit mode */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/err.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/efiemu/efiemu.h>
#include <grub/cpu/efiemu.h>
#include <grub/elf.h>
/* Check if EHDR is a valid ELF header. */
int
grub_arch_efiemu_check_header32 (void *ehdr)
{
Elf32_Ehdr *e = ehdr;
/* Check the magic numbers. */
return (e->e_ident[EI_CLASS] == ELFCLASS32
&& e->e_ident[EI_DATA] == ELFDATA2LSB
&& e->e_machine == EM_386);
}
/* Relocate symbols. */
grub_err_t
grub_arch_efiemu_relocate_symbols32 (grub_efiemu_segment_t segs,
struct grub_efiemu_elf_sym *elfsyms,
void *ehdr)
{
unsigned i;
Elf32_Ehdr *e = ehdr;
Elf32_Shdr *s;
grub_err_t err;
grub_dprintf ("efiemu", "relocating symbols %d %d\n",
e->e_shoff, e->e_shnum);
for (i = 0, s = (Elf32_Shdr *) ((char *) e + e->e_shoff);
i < e->e_shnum;
i++, s = (Elf32_Shdr *) ((char *) s + e->e_shentsize))
if (s->sh_type == SHT_REL)
{
grub_efiemu_segment_t seg;
grub_dprintf ("efiemu", "shtrel\n");
/* Find the target segment. */
for (seg = segs; seg; seg = seg->next)
if (seg->section == s->sh_info)
break;
if (seg)
{
Elf32_Rel *rel, *max;
for (rel = (Elf32_Rel *) ((char *) e + s->sh_offset),
max = rel + s->sh_size / s->sh_entsize;
rel < max;
rel++)
{
Elf32_Word *addr;
struct grub_efiemu_elf_sym sym;
if (seg->size < rel->r_offset)
return grub_error (GRUB_ERR_BAD_MODULE,
"reloc offset is out of the segment");
addr = (Elf32_Word *)
((char *) grub_efiemu_mm_obtain_request (seg->handle)
+ seg->off + rel->r_offset);
sym = elfsyms[ELF32_R_SYM (rel->r_info)];
switch (ELF32_R_TYPE (rel->r_info))
{
case R_386_32:
if ((err = grub_efiemu_write_value
(addr, sym.off + *addr, sym.handle, 0,
seg->ptv_rel_needed, sizeof (grub_uint32_t))))
return err;
break;
case R_386_PC32:
if ((err = grub_efiemu_write_value
(addr, sym.off + *addr - rel->r_offset
- seg->off, sym.handle, seg->handle,
seg->ptv_rel_needed, sizeof (grub_uint32_t))))
return err;
break;
default:
return grub_error (GRUB_ERR_BAD_OS,
"unrecognised relocation");
}
}
}
}
return GRUB_ERR_NONE;
}