grub/loader/multiboot_elfxx.c
Vladimir 'phcoder' Serbinenko f0847685dd Merge mainline into newreloc
2010-04-03 17:47:59 +02:00

202 lines
6.1 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2007,2008,2009 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/>.
*/
#if defined(MULTIBOOT_LOAD_ELF32)
# define XX 32
# define E_MACHINE MULTIBOOT_ELF32_MACHINE
# define ELFCLASSXX ELFCLASS32
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Phdr Elf32_Phdr
#elif defined(MULTIBOOT_LOAD_ELF64)
# define XX 64
# define E_MACHINE MULTIBOOT_ELF64_MACHINE
# define ELFCLASSXX ELFCLASS64
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Phdr Elf64_Phdr
#else
#error "I'm confused"
#endif
#include <grub/i386/relocator.h>
#define CONCAT(a,b) CONCAT_(a, b)
#define CONCAT_(a,b) a ## b
/* Check if BUFFER contains ELF32 (or ELF64). */
static int
CONCAT(grub_multiboot_is_elf, XX) (void *buffer)
{
Elf_Ehdr *ehdr = (Elf_Ehdr *) buffer;
return ehdr->e_ident[EI_CLASS] == ELFCLASSXX;
}
static grub_err_t
CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, void *buffer)
{
Elf_Ehdr *ehdr = (Elf_Ehdr *) buffer;
char *phdr_base;
int i;
if (ehdr->e_ident[EI_CLASS] != ELFCLASSXX)
return grub_error (GRUB_ERR_UNKNOWN_OS, "invalid ELF class");
if (ehdr->e_ident[EI_MAG0] != ELFMAG0
|| ehdr->e_ident[EI_MAG1] != ELFMAG1
|| ehdr->e_ident[EI_MAG2] != ELFMAG2
|| ehdr->e_ident[EI_MAG3] != ELFMAG3
|| ehdr->e_version != EV_CURRENT
|| ehdr->e_ident[EI_DATA] != ELFDATA2LSB
|| ehdr->e_machine != E_MACHINE)
return grub_error(GRUB_ERR_UNKNOWN_OS, "no valid ELF header found");
if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN)
return grub_error (GRUB_ERR_UNKNOWN_OS, "invalid ELF file type");
/* FIXME: Should we support program headers at strange locations? */
if (ehdr->e_phoff + ehdr->e_phnum * ehdr->e_phentsize > MULTIBOOT_SEARCH)
return grub_error (GRUB_ERR_BAD_OS, "program header at a too high offset");
#ifdef MULTIBOOT_LOAD_ELF64
/* We still in 32-bit mode. */
if (ehdr->e_entry > 0xffffffff)
return grub_error (GRUB_ERR_BAD_OS, "invalid entry point for ELF64");
#endif
phdr_base = (char *) buffer + ehdr->e_phoff;
#define phdr(i) ((Elf_Phdr *) (phdr_base + (i) * ehdr->e_phentsize))
/* Load every loadable segment in memory. */
for (i = 0; i < ehdr->e_phnum; i++)
{
if (phdr(i)->p_type == PT_LOAD && phdr(i)->p_filesz != 0)
{
grub_err_t err;
void *source;
grub_dprintf ("multiboot_loader", "segment %d: paddr=0x%lx, memsz=0x%lx, vaddr=0x%lx\n",
i, (long) phdr(i)->p_paddr, (long) phdr(i)->p_memsz, (long) phdr(i)->p_vaddr);
err = grub_relocator_alloc_chunk_addr (grub_multiboot_relocator,
&source, phdr(i)->p_paddr,
phdr(i)->p_memsz);
if (err)
{
grub_dprintf ("multiboot_loader", "Error loading phdr %d\n", i);
return err;
}
if (grub_file_seek (file, (grub_off_t) phdr(i)->p_offset)
== (grub_off_t) -1)
return grub_error (GRUB_ERR_BAD_OS,
"invalid offset in program header");
if (grub_file_read (file, source, phdr(i)->p_filesz)
!= (grub_ssize_t) phdr(i)->p_filesz)
return grub_error (GRUB_ERR_BAD_OS,
"couldn't read segment from file");
if (phdr(i)->p_filesz < phdr(i)->p_memsz)
grub_memset ((grub_uint8_t *) source + phdr(i)->p_filesz, 0,
phdr(i)->p_memsz - phdr(i)->p_filesz);
}
}
for (i = 0; i < ehdr->e_phnum; i++)
if (phdr(i)->p_vaddr <= ehdr->e_entry
&& phdr(i)->p_vaddr + phdr(i)->p_memsz > ehdr->e_entry)
{
grub_multiboot_payload_eip = (ehdr->e_entry - phdr(i)->p_vaddr)
+ phdr(i)->p_paddr;
break;
}
if (i == ehdr->e_phnum)
return grub_error (GRUB_ERR_BAD_OS, "entry point isn't in a segment");
if (ehdr->e_shnum)
{
grub_uint8_t *shdr, *shdrptr;
shdr = grub_malloc (ehdr->e_shnum * ehdr->e_shentsize);
if (!shdr)
return grub_errno;
if (grub_file_seek (file, ehdr->e_shoff) == (grub_off_t) -1)
return grub_error (GRUB_ERR_BAD_OS,
"invalid offset to section headers");
if (grub_file_read (file, shdr, ehdr->e_shnum * ehdr->e_shentsize)
!= (grub_ssize_t) ehdr->e_shnum * ehdr->e_shentsize)
return grub_error (GRUB_ERR_BAD_OS,
"couldn't read sections headers from file");
for (shdrptr = shdr, i = 0; i < ehdr->e_shnum;
shdrptr += ehdr->e_shentsize, i++)
{
Elf_Shdr *sh = (Elf_Shdr *) shdrptr;
void *src;
grub_addr_t target;
grub_err_t err;
/* This section is a loaded section,
so we don't care. */
if (sh->sh_addr != 0)
continue;
/* This section is empty, so we don't care. */
if (sh->sh_size == 0)
continue;
err
= grub_relocator_alloc_chunk_align (grub_multiboot_relocator,
&src, &target, 0,
(0xffffffff - sh->sh_size) + 1,
sh->sh_size,
sh->sh_addralign,
GRUB_RELOCATOR_PREFERENCE_NONE);
if (err)
{
grub_dprintf ("multiboot_loader", "Error loading shdr %d\n", i);
return err;
}
if (grub_file_seek (file, sh->sh_offset) == (grub_off_t) -1)
return grub_error (GRUB_ERR_BAD_OS,
"invalid offset in section header");
if (grub_file_read (file, src, sh->sh_size)
!= (grub_ssize_t) sh->sh_size)
return grub_error (GRUB_ERR_BAD_OS,
"couldn't read segment from file");
sh->sh_addr = target;
}
grub_multiboot_add_elfsyms (ehdr->e_shnum, ehdr->e_shentsize,
ehdr->e_shstrndx, shdr);
}
#undef phdr
return grub_errno;
}
#undef XX
#undef E_MACHINE
#undef ELFCLASSXX
#undef Elf_Ehdr
#undef Elf_Phdr