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Diffstat (limited to 'backends/plugins/elf/ppc-loader.cpp')
| -rw-r--r-- | backends/plugins/elf/ppc-loader.cpp | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/backends/plugins/elf/ppc-loader.cpp b/backends/plugins/elf/ppc-loader.cpp new file mode 100644 index 0000000000..4be27ac9fc --- /dev/null +++ b/backends/plugins/elf/ppc-loader.cpp @@ -0,0 +1,127 @@ +/* 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 2 + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#if defined(DYNAMIC_MODULES) && 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: Out of memory."); + 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_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(PPC_TARGET) */ + |