1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 #include <stdio.h> 26 #include <errno.h> 27 #include <assert.h> 28 #include <unistd.h> 29 #include <libintl.h> 30 #include <sys/multiboot.h> 31 #include <sys/sysmacros.h> 32 33 #include "bblk_einfo.h" 34 #include "boot_utils.h" 35 #include "mboot_extra.h" 36 37 /* 38 * Common functions to deal with the fake-multiboot encapsulation of the 39 * bootblock and the location of the extra information area. 40 */ 41 42 /* mboot checksum routine. */ 43 uint32_t 44 compute_checksum(char *data, uint32_t size) 45 { 46 uint32_t *ck_ptr; 47 uint32_t cksum = 0; 48 int i; 49 50 ck_ptr = (uint32_t *)data; 51 for (i = 0; i < size; i += sizeof (uint32_t)) 52 cksum += *ck_ptr++; 53 54 return (-cksum); 55 } 56 57 /* Given a buffer, look for a multiboot header within it. */ 58 int 59 find_multiboot(char *buffer, uint32_t buf_size, uint32_t *mboot_off) 60 { 61 multiboot_header_t *mboot; 62 uint32_t *iter; 63 uint32_t cksum; 64 uint32_t boundary; 65 int i = 0; 66 67 iter = (uint32_t *)buffer; 68 *mboot_off = 0; 69 /* multiboot header has to be within the first 32K. */ 70 boundary = MBOOT_SCAN_SIZE; 71 if (boundary > buf_size) 72 boundary = buf_size; 73 74 boundary = boundary - sizeof (multiboot_header_t); 75 76 for (i = 0; i < boundary; i += 4, iter++) { 77 78 mboot = (multiboot_header_t *)iter; 79 if (mboot->magic != MB_HEADER_MAGIC) 80 continue; 81 82 /* Found magic signature -- check checksum. */ 83 cksum = -(mboot->flags + mboot->magic); 84 if (mboot->checksum != cksum) { 85 BOOT_DEBUG("multiboot magic found at %p, but checksum " 86 "mismatches (is %x, should be %x)\n", mboot, 87 mboot->checksum, cksum); 88 continue; 89 } else { 90 if (!(mboot->flags & BB_MBOOT_AOUT_FLAG)) { 91 BOOT_DEBUG("multiboot structure found, but no " 92 "AOUT kludge specified, skipping.\n"); 93 continue; 94 } else { 95 /* proper multiboot structure found. */ 96 *mboot_off = i; 97 return (BC_SUCCESS); 98 } 99 } 100 } 101 102 return (BC_ERROR); 103 } 104 105 /* 106 * Given a pointer to the extra information area (a sequence of bb_header_ext_t 107 * + payload chunks), find the extended information structure. 108 */ 109 bblk_einfo_t * 110 find_einfo(char *extra) 111 { 112 bb_header_ext_t *ext_header; 113 bblk_einfo_t *einfo; 114 uint32_t cksum; 115 116 assert(extra != NULL); 117 118 ext_header = (bb_header_ext_t *)extra; 119 cksum = compute_checksum(extra + sizeof (bb_header_ext_t), 120 ext_header->size); 121 BOOT_DEBUG("Extended information header checksum is %x\n", cksum); 122 123 if (cksum != ext_header->checksum) { 124 BOOT_DEBUG("Unable to find extended versioning information, " 125 "data looks corrupted\n"); 126 return (NULL); 127 } 128 129 /* 130 * Currently we only have one extra header so it must be encapsulating 131 * the extended information structure. 132 */ 133 einfo = (bblk_einfo_t *)(extra + sizeof (bb_header_ext_t)); 134 if (memcmp(einfo->magic, EINFO_MAGIC, EINFO_MAGIC_SIZE) != 0) { 135 BOOT_DEBUG("Unable to read stage2 extended versioning " 136 "information, wrong magic identifier\n"); 137 BOOT_DEBUG("Found %s, expected %s\n", einfo->magic, 138 EINFO_MAGIC); 139 return (NULL); 140 } 141 142 return (einfo); 143 } 144 145 /* 146 * Given a pointer to the extra area, add the extended information structure 147 * encapsulated by a bb_header_ext_t structure. 148 */ 149 void 150 add_einfo(char *extra, char *updt_str, bblk_hs_t *hs, uint32_t avail_space) 151 { 152 bb_header_ext_t *ext_hdr; 153 uint32_t used_space; 154 unsigned char *dest; 155 int ret; 156 157 assert(extra != NULL); 158 159 if (updt_str == NULL) { 160 BOOT_DEBUG("WARNING: no update string passed to " 161 "add_stage2_einfo()\n"); 162 return; 163 } 164 165 /* Reserve space for the extra header. */ 166 ext_hdr = (bb_header_ext_t *)extra; 167 dest = (unsigned char *)extra + sizeof (*ext_hdr); 168 /* Place the extended information structure. */ 169 ret = prepare_and_write_einfo(dest, updt_str, hs, avail_space, 170 &used_space); 171 if (ret != 0) { 172 (void) fprintf(stderr, gettext("Unable to write the extended " 173 "versioning information\n")); 174 return; 175 } 176 177 /* Fill the extended information associated header. */ 178 ext_hdr->size = P2ROUNDUP(used_space, 8); 179 ext_hdr->checksum = compute_checksum((char *)dest, ext_hdr->size); 180 } 181