/* dl.c - arch-dependent part of loadable module support */ /* * GRUB -- GRand Unified Bootloader * Copyright (C) 2002, 2004, 2005 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 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 GRUB; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include /* Check if EHDR is a valid ELF header. */ grub_err_t grub_arch_dl_check_header (void *ehdr) { Elf64_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) { Elf64_Ehdr *e = ehdr; Elf64_Shdr *s; Elf64_Sym *symtab; Elf64_Word entsize; unsigned i; /* Find a symbol table. */ for (i = 0, s = (Elf64_Shdr *) ((char *) e + e->e_shoff); i < e->e_shnum; i++, s = (Elf64_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"); symtab = (Elf64_Sym *) ((char *) e + s->sh_offset); entsize = s->sh_entsize; for (i = 0, s = (Elf64_Shdr *) ((char *) e + e->e_shoff); i < e->e_shnum; i++, s = (Elf64_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) { Elf64_Rela *rel, *max; for (rel = (Elf64_Rela *) ((char *) e + s->sh_offset), max = rel + s->sh_size / s->sh_entsize; rel < max; rel++) { Elf64_Xword *addr; Elf64_Sym *sym; grub_uint64_t value; if (seg->size < rel->r_offset) return grub_error (GRUB_ERR_BAD_MODULE, "reloc offset is out of the segment"); addr = (Elf64_Xword *) ((char *) seg->addr + rel->r_offset); sym = (Elf64_Sym *) ((char *) 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: *(Elf64_Half *) addr = value; break; case R_PPC_REL24: { Elf64_Sxword delta = value - (Elf64_Xword) 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: *(Elf64_Half *) addr = (value + 0x8000) >> 16; break; case R_PPC_ADDR32: *addr = value; break; case R_PPC_REL32: *addr = value - (Elf64_Xword) 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; }