diff options
Diffstat (limited to 'grub-core/kern/powerpc/dl.c')
| -rw-r--r-- | grub-core/kern/powerpc/dl.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/grub-core/kern/powerpc/dl.c b/grub-core/kern/powerpc/dl.c new file mode 100644 index 0000000..ad19e56 --- /dev/null +++ b/grub-core/kern/powerpc/dl.c @@ -0,0 +1,136 @@ +/* dl.c - arch-dependent part of loadable module support */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2002,2004,2005,2007,2009 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/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) +{ + Elf_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) +{ + Elf_Ehdr *e = ehdr; + Elf_Shdr *s; + Elf_Word entsize; + unsigned i; + + /* Find a symbol table. */ + for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff); + i < e->e_shnum; + i++, s = (Elf_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 = (Elf_Shdr *) ((char *) e + e->e_shoff); + i < e->e_shnum; + i++, s = (Elf_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) + { + Elf_Rela *rel, *max; + + for (rel = (Elf_Rela *) ((char *) e + s->sh_offset), + max = rel + s->sh_size / s->sh_entsize; + rel < max; + rel++) + { + Elf_Word *addr; + Elf_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 = (Elf_Word *) ((char *) seg->addr + rel->r_offset); + sym = (Elf_Sym *) ((char *) mod->symtab + + entsize * ELF_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 (ELF_R_TYPE (rel->r_info)) + { + case R_PPC_ADDR16_LO: + *(Elf_Half *) addr = value; + break; + + case R_PPC_REL24: + { + Elf_Sword delta = value - (Elf_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: + *(Elf_Half *) addr = (value + 0x8000) >> 16; + break; + + case R_PPC_ADDR32: + *addr = value; + break; + + case R_PPC_REL32: + *addr = value - (Elf_Word) addr; + break; + + default: + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + "this relocation (%d) is not implemented yet", + ELF_R_TYPE (rel->r_info)); + } + } + } + } + + return GRUB_ERR_NONE; +} |