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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/scummsys.h"
#if defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER) && defined(PPC_TARGET)
#include "backends/plugins/elf/elf-loader.h"
#include "backends/plugins/elf/ppc-loader.h"
#include "common/debug.h"
bool PPCDLObject::relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment) {
Elf32_Rela *rel = NULL;
if (!(rel = (Elf32_Rela *)malloc(size))) {
warning("elfloader: Could not allocate %d bytes for the relocation table", size);
return false;
}
if (!_file->seek(offset, SEEK_SET) || _file->read(rel, size) != size) {
warning("elfloader: Relocation table load failed.");
free(rel);
return false;
}
uint32 cnt = size / sizeof(*rel);
debug(2, "elfloader: Loaded relocation table. %d entries. base address=%p", cnt, relSegment);
uint32 *src;
uint32 value;
for (uint32 i = 0; i < cnt; i++) {
// Get the symbol this relocation entry is referring to
Elf32_Sym *sym = _symtab + (REL_INDEX(rel[i].r_info));
// Get the target instruction in the code
src = (uint32 *)((char *)relSegment + rel[i].r_offset - _segmentVMA);
value = sym->st_value + rel[i].r_addend;
//debug(8, "elfloader: i=%05d %p +0x%04x: (0x%08x) 0x%08x ", i, src, rel[i].r_addend, sym->st_value, *src);
switch (REL_TYPE(rel[i].r_info)) {
case R_PPC_NONE:
debug(8, "elfloader: R_PPC_NONE");
break;
case R_PPC_ADDR32:
*src = value;
debug(8, "elfloader: R_PPC_ADDR32 -> 0x%08x", *src);
break;
case R_PPC_ADDR16_LO:
*(uint16 *)src = value;
debug(8, "elfloader: R_PPC_ADDR16_LO -> 0x%08x", *src);
break;
case R_PPC_ADDR16_HI:
*(uint16 *)src = value >> 16;
debug(8, "elfloader: R_PPC_ADDR16_HA -> 0x%08x", *src);
break;
case R_PPC_ADDR16_HA:
*(uint16 *)src = (value + 0x8000) >> 16;
debug(8, "elfloader: R_PPC_ADDR16_HA -> 0x%08x", *src);
break;
case R_PPC_REL24:
*src = (*src & ~0x03fffffc) | ((value - (uint32)src) & 0x03fffffc);
debug(8, "elfloader: R_PPC_REL24 -> 0x%08x", *src);
break;
case R_PPC_REL32:
*src = value - (uint32)src;
debug(8, "elfloader: R_PPC_REL32 -> 0x%08x", *src);
break;
default:
warning("elfloader: Unknown relocation type %d", REL_TYPE(rel[i].r_info));
free(rel);
return false;
}
}
free(rel);
return true;
}
bool PPCDLObject::relocateRels(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr) {
for (uint32 i = 0; i < ehdr->e_shnum; i++) {
Elf32_Shdr *curShdr = &(shdr[i]);
if ((curShdr->sh_type == SHT_REL) &&
curShdr->sh_entsize == sizeof(Elf32_Rel) &&
int32(curShdr->sh_link) == _symtab_sect &&
curShdr->sh_info < ehdr->e_shnum &&
(shdr[curShdr->sh_info].sh_flags & SHF_ALLOC)) {
warning("elfloader: REL entries not supported!");
return false;
}
if ((curShdr->sh_type == SHT_RELA) &&
curShdr->sh_entsize == sizeof(Elf32_Rela) &&
int32(curShdr->sh_link) == _symtab_sect &&
curShdr->sh_info < ehdr->e_shnum &&
(shdr[curShdr->sh_info].sh_flags & SHF_ALLOC)) {
if (!relocate(curShdr->sh_offset, curShdr->sh_size, _segment))
return false;
}
}
return true;
}
#endif /* defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER) && defined(PPC_TARGET) */
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