| Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation; either version 2 of the |
| 7 | * License, or any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 17 | */ |
| 18 | |
| 19 | FILE_LICENCE ( GPL2_OR_LATER ); |
| 20 | |
| 21 | #include <errno.h> |
| 22 | #include <elf.h> |
| 23 | #include <gpxe/image.h> |
| 24 | #include <gpxe/elf.h> |
| 25 | #include <gpxe/features.h> |
| 26 | #include <gpxe/init.h> |
| 27 | |
| 28 | /** |
| 29 | * @file |
| 30 | * |
| 31 | * ELF bootable image |
| 32 | * |
| 33 | */ |
| 34 | |
| 35 | FEATURE ( FEATURE_IMAGE, "ELF", DHCP_EB_FEATURE_ELF, 1 ); |
| 36 | |
| 37 | struct image_type elfboot_image_type __image_type ( PROBE_NORMAL ); |
| 38 | |
| 39 | /** |
| 40 | * Execute ELF image |
| 41 | * |
| 42 | * @v image ELF image |
| 43 | * @ret rc Return status code |
| 44 | */ |
| 45 | static int elfboot_exec ( struct image *image ) { |
| 46 | physaddr_t entry = image->priv.phys; |
| 47 | |
| 48 | /* An ELF image has no callback interface, so we need to shut |
| 49 | * down before invoking it. |
| 50 | */ |
| 51 | shutdown ( SHUTDOWN_BOOT ); |
| 52 | |
| 53 | /* Jump to OS with flat physical addressing */ |
| 54 | DBGC ( image, "ELF %p starting execution at %lx\n", image, entry ); |
| 55 | __asm__ __volatile__ ( PHYS_CODE ( "call *%%edi\n\t" ) |
| 56 | : : "D" ( entry ) |
| 57 | : "eax", "ebx", "ecx", "edx", "esi", "ebp", |
| 58 | "memory" ); |
| 59 | |
| 60 | DBGC ( image, "ELF %p returned\n", image ); |
| 61 | |
| 62 | /* It isn't safe to continue after calling shutdown() */ |
| 63 | while ( 1 ) {} |
| 64 | |
| 65 | return -ECANCELED; /* -EIMPOSSIBLE, anyone? */ |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * Load ELF image into memory |
| 70 | * |
| 71 | * @v image ELF file |
| 72 | * @ret rc Return status code |
| 73 | */ |
| 74 | static int elfboot_load ( struct image *image ) { |
| 75 | Elf32_Ehdr ehdr; |
| 76 | static const uint8_t e_ident[] = { |
| 77 | [EI_MAG0] = ELFMAG0, |
| 78 | [EI_MAG1] = ELFMAG1, |
| 79 | [EI_MAG2] = ELFMAG2, |
| 80 | [EI_MAG3] = ELFMAG3, |
| 81 | [EI_CLASS] = ELFCLASS32, |
| 82 | [EI_DATA] = ELFDATA2LSB, |
| 83 | [EI_VERSION] = EV_CURRENT, |
| 84 | }; |
| 85 | int rc; |
| 86 | |
| 87 | /* Read ELF header */ |
| 88 | copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) ); |
| 89 | if ( memcmp ( ehdr.e_ident, e_ident, sizeof ( e_ident ) ) != 0 ) { |
| 90 | DBG ( "Invalid ELF identifier\n" ); |
| 91 | return -ENOEXEC; |
| 92 | } |
| 93 | |
| 94 | /* This is an ELF image, valid or otherwise */ |
| 95 | if ( ! image->type ) |
| 96 | image->type = &elfboot_image_type; |
| 97 | |
| 98 | /* Load the image using core ELF support */ |
| 99 | if ( ( rc = elf_load ( image ) ) != 0 ) { |
| 100 | DBGC ( image, "ELF %p could not load: %s\n", |
| 101 | image, strerror ( rc ) ); |
| 102 | return rc; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | /** ELF image type */ |
| 109 | struct image_type elfboot_image_type __image_type ( PROBE_NORMAL ) = { |
| 110 | .name = "ELF", |
| 111 | .load = elfboot_load, |
| 112 | .exec = elfboot_exec, |
| 113 | }; |