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/*
* Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program 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 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <errno.h>
#include <elf.h>
#include <ipxe/image.h>
#include <ipxe/elf.h>
#include <ipxe/features.h>
#include <ipxe/init.h>
/**
* @file
*
* ELF bootable image
*
*/
FEATURE ( FEATURE_IMAGE, "ELF", DHCP_EB_FEATURE_ELF, 1 );
/**
* Execute ELF image
*
* @v image ELF image
* @ret rc Return status code
*/
static int elfboot_exec ( struct image *image ) {
physaddr_t entry;
physaddr_t max;
int rc;
/* Load the image using core ELF support */
if ( ( rc = elf_load ( image, &entry, &max ) ) != 0 ) {
DBGC ( image, "ELF %p could not load: %s\n",
image, strerror ( rc ) );
return rc;
}
/* An ELF image has no callback interface, so we need to shut
* down before invoking it.
*/
shutdown_boot();
/* Jump to OS with flat physical addressing */
DBGC ( image, "ELF %p starting execution at %lx\n", image, entry );
__asm__ __volatile__ ( PHYS_CODE ( "pushl %%ebp\n\t" /* gcc bug */
"call *%%edi\n\t"
"popl %%ebp\n\t" /* gcc bug */ )
: : "D" ( entry )
: "eax", "ebx", "ecx", "edx", "esi", "memory" );
DBGC ( image, "ELF %p returned\n", image );
/* It isn't safe to continue after calling shutdown() */
while ( 1 ) {}
return -ECANCELED; /* -EIMPOSSIBLE, anyone? */
}
/**
* Check that ELF segment uses flat physical addressing
*
* @v image ELF file
* @v phdr ELF program header
* @v dest Destination address
* @ret rc Return status code
*/
static int elfboot_check_segment ( struct image *image, Elf_Phdr *phdr,
physaddr_t dest ) {
/* Check that ELF segment uses flat physical addressing */
if ( phdr->p_vaddr != dest ) {
DBGC ( image, "ELF %p uses virtual addressing (phys %x, "
"virt %x)\n", image, phdr->p_paddr, phdr->p_vaddr );
return -ENOEXEC;
}
return 0;
}
/**
* Probe ELF image
*
* @v image ELF file
* @ret rc Return status code
*/
static int elfboot_probe ( struct image *image ) {
Elf32_Ehdr ehdr;
static const uint8_t e_ident[] = {
[EI_MAG0] = ELFMAG0,
[EI_MAG1] = ELFMAG1,
[EI_MAG2] = ELFMAG2,
[EI_MAG3] = ELFMAG3,
[EI_CLASS] = ELFCLASS32,
[EI_DATA] = ELFDATA2LSB,
[EI_VERSION] = EV_CURRENT,
};
physaddr_t entry;
physaddr_t max;
int rc;
/* Read ELF header */
copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) );
if ( memcmp ( ehdr.e_ident, e_ident, sizeof ( e_ident ) ) != 0 ) {
DBGC ( image, "Invalid ELF identifier\n" );
return -ENOEXEC;
}
/* Check that this image uses flat physical addressing */
if ( ( rc = elf_segments ( image, &ehdr, elfboot_check_segment,
&entry, &max ) ) != 0 ) {
DBGC ( image, "Unloadable ELF image\n" );
return rc;
}
return 0;
}
/** ELF image type */
struct image_type elfboot_image_type __image_type ( PROBE_NORMAL ) = {
.name = "ELF",
.probe = elfboot_probe,
.exec = elfboot_exec,
};
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