1 /* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 * 5 * Data structure definitions for verified boot, for on-disk / in-eeprom 6 * data. 7 */ 8 9 #ifndef VBOOT_REFERENCE_VBOOT_2STRUCT_H_ 10 #define VBOOT_REFERENCE_VBOOT_2STRUCT_H_ 11 #include <stdint.h> 12 #include "2crypto.h" 13 14 /* 15 * Key block flags. 16 * 17 *The following flags set where the key is valid. Not used by firmware 18 * verification; only kernel verification. 19 */ 20 #define VB2_KEY_BLOCK_FLAG_DEVELOPER_0 0x01 /* Developer switch off */ 21 #define VB2_KEY_BLOCK_FLAG_DEVELOPER_1 0x02 /* Developer switch on */ 22 #define VB2_KEY_BLOCK_FLAG_RECOVERY_0 0x04 /* Not recovery mode */ 23 #define VB2_KEY_BLOCK_FLAG_RECOVERY_1 0x08 /* Recovery mode */ 24 #define VB2_GBB_HWID_DIGEST_SIZE 32 25 26 /****************************************************************************/ 27 28 /* Flags for vb2_shared_data.flags */ 29 enum vb2_shared_data_flags { 30 /* User has explicitly and physically requested recovery */ 31 VB2_SD_FLAG_MANUAL_RECOVERY = (1 << 0), 32 33 /* Developer mode is enabled */ 34 VB2_SD_DEV_MODE_ENABLED = (1 << 1), 35 36 /* 37 * TODO: might be nice to add flags for why dev mode is enabled - via 38 * gbb, virtual dev switch, or forced on for testing. 39 */ 40 }; 41 42 /* Flags for vb2_shared_data.status */ 43 enum vb2_shared_data_status { 44 /* Reinitialized NV data due to invalid checksum */ 45 VB2_SD_STATUS_NV_REINIT = (1 << 0), 46 47 /* NV data has been initialized */ 48 VB2_SD_STATUS_NV_INIT = (1 << 1), 49 50 /* Secure data initialized */ 51 VB2_SD_STATUS_SECDATA_INIT = (1 << 2), 52 53 /* Chose a firmware slot */ 54 VB2_SD_STATUS_CHOSE_SLOT = (1 << 3), 55 }; 56 57 /* 58 * Data shared between vboot API calls. Stored at the start of the work 59 * buffer. 60 */ 61 struct vb2_shared_data { 62 /* Flags; see enum vb2_shared_data_flags */ 63 uint32_t flags; 64 65 /* Flags from GBB header */ 66 uint32_t gbb_flags; 67 68 /* 69 * Reason we are in recovery mode this boot (enum vb2_nv_recovery), or 70 * 0 if we aren't. 71 */ 72 uint32_t recovery_reason; 73 74 /* Firmware slot used last boot (0=A, 1=B) */ 75 uint32_t last_fw_slot; 76 77 /* Result of last boot (enum vb2_fw_result) */ 78 uint32_t last_fw_result; 79 80 /* Firmware slot used this boot */ 81 uint32_t fw_slot; 82 83 /* 84 * Version for this slot (top 16 bits = key, lower 16 bits = firmware). 85 * 86 * TODO: Make this a union to allow getting/setting those versions 87 * separately? 88 */ 89 uint32_t fw_version; 90 91 /* Version stored in secdata (must be <= fw_version to boot). */ 92 uint32_t fw_version_secdata; 93 94 /* 95 * Status flags for this boot; see enum vb2_shared_data_status. Status 96 * is "what we've done"; flags above are "decisions we've made". 97 */ 98 uint32_t status; 99 100 /********************************************************************** 101 * Temporary variables used during firmware verification. These don't 102 * really need to persist through to the OS, but there's nowhere else 103 * we can put them. 104 */ 105 106 /* Root key offset and size from GBB header */ 107 uint32_t gbb_rootkey_offset; 108 uint32_t gbb_rootkey_size; 109 110 /* HWID digest from GBB header */ 111 uint8_t gbb_hwid_digest[VB2_GBB_HWID_DIGEST_SIZE]; 112 113 /* Offset of preamble from start of vblock */ 114 uint32_t vblock_preamble_offset; 115 116 /* 117 * Offset and size of packed data key in work buffer. Size is 0 if 118 * data key is not stored in the work buffer. 119 */ 120 uint32_t workbuf_data_key_offset; 121 uint32_t workbuf_data_key_size; 122 123 /* 124 * Offset and size of firmware preamble in work buffer. Size if 0 if 125 * preamble is not stored in the work buffer. 126 */ 127 uint32_t workbuf_preamble_offset; 128 uint32_t workbuf_preamble_size; 129 130 /* 131 * Offset and size of hash context in work buffer. Size if 0 if 132 * hash context is not stored in the work buffer. 133 */ 134 uint32_t workbuf_hash_offset; 135 uint32_t workbuf_hash_size; 136 137 /* 138 * Current tag we're hashing 139 * 140 * For new structs, this is the offset of the vb2_signature struct 141 * in the work buffer. 142 * 143 * TODO: rename to workbuf_hash_sig_offset when vboot1 structs are 144 * deprecated. 145 */ 146 uint32_t hash_tag; 147 148 /* Amount of data we still expect to hash */ 149 uint32_t hash_remaining_size; 150 151 } __attribute__((packed)); 152 153 /****************************************************************************/ 154 155 /* Signature at start of the GBB 156 * Note that if you compile in the signature as is, you are likely to break any 157 * tools that search for the signature. */ 158 #define VB2_GBB_SIGNATURE "$GBB" 159 #define VB2_GBB_SIGNATURE_SIZE 4 160 #define VB2_GBB_XOR_CHARS "****" 161 /* TODO: can we write a macro to produce this at compile time? */ 162 #define VB2_GBB_XOR_SIGNATURE { 0x0e, 0x6d, 0x68, 0x68 } 163 164 /* VB2 GBB struct version */ 165 #define VB2_GBB_MAJOR_VER 1 166 #define VB2_GBB_MINOR_VER 2 167 /* v1.2 - added fields for sha256 digest of the HWID */ 168 169 /* Flags for vb2_gbb_header.flags */ 170 enum vb2_gbb_flag { 171 /* 172 * Reduce the dev screen delay to 2 sec from 30 sec to speed up 173 * factory. 174 */ 175 VB2_GBB_FLAG_DEV_SCREEN_SHORT_DELAY = (1 << 0), 176 177 /* 178 * BIOS should load option ROMs from arbitrary PCI devices. We'll never 179 * enable this ourselves because it executes non-verified code, but if 180 * a customer wants to void their warranty and set this flag in the 181 * read-only flash, they should be able to do so. 182 */ 183 VB2_GBB_FLAG_LOAD_OPTION_ROMS = (1 << 1), 184 185 /* 186 * The factory flow may need the BIOS to boot a non-ChromeOS kernel if 187 * the dev-switch is on. This flag allows that. 188 */ 189 VB2_GBB_FLAG_ENABLE_ALTERNATE_OS = (1 << 2), 190 191 /* 192 * Force dev switch on, regardless of physical/keyboard dev switch 193 * position. 194 */ 195 VB2_GBB_FLAG_FORCE_DEV_SWITCH_ON = (1 << 3), 196 197 /* Allow booting from USB in dev mode even if dev_boot_usb=0. */ 198 VB2_GBB_FLAG_FORCE_DEV_BOOT_USB = (1 << 4), 199 200 /* Disable firmware rollback protection. */ 201 VB2_GBB_FLAG_DISABLE_FW_ROLLBACK_CHECK = (1 << 5), 202 203 /* Allow Enter key to trigger dev->tonorm screen transition */ 204 VB2_GBB_FLAG_ENTER_TRIGGERS_TONORM = (1 << 6), 205 206 /* Allow booting Legacy OSes in dev mode even if dev_boot_legacy=0. */ 207 VB2_GBB_FLAG_FORCE_DEV_BOOT_LEGACY = (1 << 7), 208 209 /* Allow booting using alternate keys for FAFT servo testing */ 210 VB2_GBB_FLAG_FAFT_KEY_OVERIDE = (1 << 8), 211 212 /* Disable EC software sync */ 213 VB2_GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC = (1 << 9), 214 215 /* Default to booting legacy OS when dev screen times out */ 216 VB2_GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY = (1 << 10), 217 218 /* Disable PD software sync */ 219 VB2_GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC = (1 << 11), 220 }; 221 222 struct vb2_gbb_header { 223 /* Fields present in version 1.1 */ 224 uint8_t signature[VB2_GBB_SIGNATURE_SIZE]; /* VB2_GBB_SIGNATURE */ 225 uint16_t major_version; /* See VB2_GBB_MAJOR_VER */ 226 uint16_t minor_version; /* See VB2_GBB_MINOR_VER */ 227 uint32_t header_size; /* Size of GBB header in bytes */ 228 uint32_t flags; /* Flags (see enum vb2_gbb_flag) */ 229 230 /* Offsets (from start of header) and sizes (in bytes) of components */ 231 uint32_t hwid_offset; /* HWID */ 232 uint32_t hwid_size; 233 uint32_t rootkey_offset; /* Root key */ 234 uint32_t rootkey_size; 235 uint32_t bmpfv_offset; /* BMP FV */ 236 uint32_t bmpfv_size; 237 uint32_t recovery_key_offset; /* Recovery key */ 238 uint32_t recovery_key_size; 239 240 /* Added in version 1.2 */ 241 uint8_t hwid_digest[VB2_GBB_HWID_DIGEST_SIZE]; /* SHA-256 of HWID */ 242 243 /* Pad to match EXPECETED_VB2_GBB_HEADER_SIZE. Initialize to 0. */ 244 uint8_t pad[48]; 245 } __attribute__((packed)); 246 247 /* The GBB is used outside of vboot_reference, so this size is important. */ 248 #define EXPECTED_VB2_GBB_HEADER_SIZE 128 249 250 #endif /* VBOOT_REFERENCE_VBOOT_2STRUCT_H_ */ 251