grub/loader/i386/multiboot_elfxx.c
robertmh 8a31787ff5 2009-02-27 Robert Millan <rmh@aybabtu.com>
Factorize elf32 / elf64 code in Multiboot loader.  This will
        prevent it from getting out of sync again.

        * loader/i386/multiboot.c (grub_multiboot_is_elf32,
        grub_multiboot_load_elf32, grub_multiboot_is_elf64,
        grub_multiboot_load_elf64): Move from here ...
        * loader/i386/multiboot_elfxx.c (grub_multiboot_is_elf,
        grub_multiboot_load_elf): ... to here (new file).
2009-02-27 23:04:46 +00:00

137 lines
4.5 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 EM_386
# define ELFCLASSXX ELFCLASS32
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Phdr Elf32_Phdr
#elif defined(MULTIBOOT_LOAD_ELF64)
# define XX 64
# define E_MACHINE EM_X86_64
# define ELFCLASSXX ELFCLASS64
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Phdr Elf64_Phdr
#else
#error "I'm confused"
#endif
#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 lowest_segment = 0, highest_segment = 0;
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)
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))
for (i = 0; i < ehdr->e_phnum; i++)
if (phdr(i)->p_type == PT_LOAD && phdr(i)->p_filesz != 0)
{
if (phdr(i)->p_paddr < phdr(lowest_segment)->p_paddr)
lowest_segment = i;
if (phdr(i)->p_paddr > phdr(highest_segment)->p_paddr)
highest_segment = i;
}
grub_multiboot_payload_size += (phdr(highest_segment)->p_paddr + phdr(highest_segment)->p_memsz) - phdr(lowest_segment)->p_paddr;
grub_multiboot_payload_dest = phdr(lowest_segment)->p_paddr;
playground = grub_malloc (RELOCATOR_SIZEOF(forward) + grub_multiboot_payload_size + RELOCATOR_SIZEOF(backward));
if (! playground)
return grub_errno;
grub_multiboot_payload_orig = (long) playground + RELOCATOR_SIZEOF(forward);
/* 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)
{
char *load_this_module_at = (char *) (grub_multiboot_payload_orig + (long) (phdr(i)->p_paddr - phdr(lowest_segment)->p_paddr));
grub_dprintf ("multiboot_loader", "segment %d: paddr=0x%lx, memsz=0x%lx\n",
i, (long) phdr(i)->p_paddr, (long) phdr(i)->p_memsz);
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, load_this_module_at, 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 (load_this_module_at + phdr(i)->p_filesz, 0,
phdr(i)->p_memsz - phdr(i)->p_filesz);
}
}
grub_multiboot_payload_entry_offset = ehdr->e_entry - phdr(lowest_segment)->p_vaddr;
#undef phdr
return grub_errno;
}
#undef XX
#undef E_MACHINE
#undef ELFCLASSXX
#undef Elf_Ehdr
#undef Elf_Phdr