diff options
Diffstat (limited to 'grub-core/kern/powerpc/dl.c')
| -rw-r--r-- | grub-core/kern/powerpc/dl.c | 169 |
1 files changed, 169 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..cdd61b3 --- /dev/null +++ b/grub-core/kern/powerpc/dl.c @@ -0,0 +1,169 @@ +/* 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> +#include <grub/i18n.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, N_("invalid arch-dependent ELF magic")); + + return GRUB_ERR_NONE; +} + +/* For low-endian reverse lis and addr_high as well as ori and addr_low. */ +struct trampoline +{ + grub_uint32_t lis; + grub_uint32_t ori; + grub_uint32_t mtctr; + grub_uint32_t bctr; +}; + +static const struct trampoline trampoline_template = + { + 0x3d800000, + 0x618c0000, + 0x7d8903a6, + 0x4e800420, + }; + +#pragma GCC diagnostic ignored "-Wcast-align" + +grub_err_t +grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp, + grub_size_t *got) +{ + const Elf_Ehdr *e = ehdr; + const Elf_Shdr *s; + unsigned i; + + *tramp = 0; + *got = 0; + + for (i = 0, s = (const Elf_Shdr *) ((const char *) e + e->e_shoff); + i < e->e_shnum; + i++, s = (const Elf_Shdr *) ((const char *) s + e->e_shentsize)) + if (s->sh_type == SHT_RELA) + { + const Elf_Rela *rel, *max; + + for (rel = (const Elf_Rela *) ((const char *) e + s->sh_offset), + max = rel + s->sh_size / s->sh_entsize; + rel < max; + rel++) + if (ELF_R_TYPE (rel->r_info) == GRUB_ELF_R_PPC_REL24 + || ELF_R_TYPE (rel->r_info) == GRUB_ELF_R_PPC_PLTREL24) + (*tramp)++; + + } + + *tramp *= sizeof (struct trampoline); + + return GRUB_ERR_NONE; +} + +/* Relocate symbols. */ +grub_err_t +grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr, + Elf_Shdr *s, grub_dl_segment_t seg) +{ + Elf_Rela *rel, *max; + + for (rel = (Elf_Rela *) ((char *) ehdr + s->sh_offset), + max = (Elf_Rela *) ((char *) rel + s->sh_size); + rel < max; + rel = (Elf_Rela *) ((char *) rel + s->sh_entsize)) + { + 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 + + mod->symsize * 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 GRUB_ELF_R_PPC_ADDR16_LO: + *(Elf_Half *) addr = value; + break; + + case GRUB_ELF_R_PPC_PLTREL24: + case GRUB_ELF_R_PPC_REL24: + { + Elf_Sword delta = value - (Elf_Word) addr; + + if (delta << 6 >> 6 != delta) + { + struct trampoline *tptr = mod->trampptr; + grub_memcpy (tptr, &trampoline_template, + sizeof (*tptr)); + delta = (grub_uint8_t *) tptr - (grub_uint8_t *) addr; + tptr->lis |= (((value) >> 16) & 0xffff); + tptr->ori |= ((value) & 0xffff); + mod->trampptr = tptr + 1; + } + + if (delta << 6 >> 6 != delta) + return grub_error (GRUB_ERR_BAD_MODULE, + "relocation overflow"); + *addr = (*addr & 0xfc000003) | (delta & 0x3fffffc); + break; + } + + case GRUB_ELF_R_PPC_ADDR16_HA: + *(Elf_Half *) addr = (value + 0x8000) >> 16; + break; + + case GRUB_ELF_R_PPC_ADDR32: + *addr = value; + break; + + case GRUB_ELF_R_PPC_REL32: + *addr = value - (Elf_Word) addr; + break; + + default: + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + N_("relocation 0x%x is not implemented yet"), + ELF_R_TYPE (rel->r_info)); + } + } + + return GRUB_ERR_NONE; +} |