137 lines
3.5 KiB
C
137 lines
3.5 KiB
C
/* dl.c - arch-dependent part of loadable module support */
|
|
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 2002,2004,2005,2007 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/dl.h>
|
|
#include <grub/elf.h>
|
|
#include <grub/misc.h>
|
|
#include <grub/err.h>
|
|
|
|
/* Check if EHDR is a valid ELF header. */
|
|
grub_err_t
|
|
grub_arch_dl_check_header (void *ehdr)
|
|
{
|
|
Elf32_Ehdr *e = ehdr;
|
|
|
|
/* Check the magic numbers. */
|
|
if (e->e_ident[EI_CLASS] != ELFCLASS32
|
|
|| e->e_ident[EI_DATA] != ELFDATA2MSB
|
|
|| e->e_machine != EM_PPC)
|
|
return grub_error (GRUB_ERR_BAD_OS, "invalid arch specific ELF magic");
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|
|
|
|
|
|
/* Relocate symbols. */
|
|
grub_err_t
|
|
grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr)
|
|
{
|
|
Elf32_Ehdr *e = ehdr;
|
|
Elf32_Shdr *s;
|
|
Elf32_Word entsize;
|
|
unsigned i;
|
|
|
|
/* Find a symbol table. */
|
|
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_SYMTAB)
|
|
break;
|
|
|
|
if (i == e->e_shnum)
|
|
return grub_error (GRUB_ERR_BAD_MODULE, "no symtab found");
|
|
|
|
entsize = s->sh_entsize;
|
|
|
|
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_RELA)
|
|
{
|
|
grub_dl_segment_t seg;
|
|
|
|
/* Find the target segment. */
|
|
for (seg = mod->segment; seg; seg = seg->next)
|
|
if (seg->section == s->sh_info)
|
|
break;
|
|
|
|
if (seg)
|
|
{
|
|
Elf32_Rela *rel, *max;
|
|
|
|
for (rel = (Elf32_Rela *) ((char *) e + s->sh_offset),
|
|
max = rel + s->sh_size / s->sh_entsize;
|
|
rel < max;
|
|
rel++)
|
|
{
|
|
Elf32_Word *addr;
|
|
Elf32_Sym *sym;
|
|
grub_uint32_t value;
|
|
|
|
if (seg->size < rel->r_offset)
|
|
return grub_error (GRUB_ERR_BAD_MODULE,
|
|
"reloc offset is out of the segment");
|
|
|
|
addr = (Elf32_Word *) ((char *) seg->addr + rel->r_offset);
|
|
sym = (Elf32_Sym *) ((char *) mod->symtab
|
|
+ entsize * ELF32_R_SYM (rel->r_info));
|
|
|
|
/* On the PPC the value does not have an explicit
|
|
addend, add it. */
|
|
value = sym->st_value + rel->r_addend;
|
|
switch (ELF32_R_TYPE (rel->r_info))
|
|
{
|
|
case R_PPC_ADDR16_LO:
|
|
*(Elf32_Half *) addr = value;
|
|
break;
|
|
|
|
case R_PPC_REL24:
|
|
{
|
|
Elf32_Sword delta = value - (Elf32_Word) addr;
|
|
|
|
if (delta << 6 >> 6 != delta)
|
|
return grub_error (GRUB_ERR_BAD_MODULE, "Relocation overflow");
|
|
*addr = (*addr & 0xfc000003) | (delta & 0x3fffffc);
|
|
break;
|
|
}
|
|
|
|
case R_PPC_ADDR16_HA:
|
|
*(Elf32_Half *) addr = (value + 0x8000) >> 16;
|
|
break;
|
|
|
|
case R_PPC_ADDR32:
|
|
*addr = value;
|
|
break;
|
|
|
|
case R_PPC_REL32:
|
|
*addr = value - (Elf32_Word) addr;
|
|
break;
|
|
|
|
default:
|
|
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
|
|
"This relocation (%d) is not implemented yet",
|
|
ELF32_R_TYPE (rel->r_info));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|