1 /* 2 * Copyright (c) 2021-2022, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 9 #include <common/debug.h> 10 #include <common/tf_crc32.h> 11 #include <common/tbbr/tbbr_img_def.h> 12 #include <drivers/fwu/fwu.h> 13 #include <drivers/fwu/fwu_metadata.h> 14 #include <drivers/io/io_storage.h> 15 16 #include <plat/common/platform.h> 17 18 /* 19 * Assert that crc_32 is the first member of fwu_metadata structure. 20 * It avoids accessing data outside of the metadata structure during 21 * CRC32 computation if the crc_32 field gets moved due the structure 22 * member(s) addition in the future. 23 */ 24 CASSERT((offsetof(struct fwu_metadata, crc_32) == 0), 25 crc_32_must_be_first_member_of_structure); 26 27 /* 28 * Ensure that the NR_OF_FW_BANKS selected by the platform is not 29 * zero and not greater than the maximum number of banks allowed 30 * by the specification. 31 */ 32 CASSERT((NR_OF_FW_BANKS > 0) && (NR_OF_FW_BANKS <= NR_OF_MAX_FW_BANKS), 33 assert_fwu_num_banks_invalid_value); 34 35 #define FWU_METADATA_VERSION 2U 36 #define FWU_FW_STORE_DESC_OFFSET 0x20U 37 38 static struct fwu_metadata metadata; 39 static bool is_metadata_initialized __unused; 40 41 /******************************************************************************* 42 * Compute CRC32 of the FWU metadata, and check it against the CRC32 value 43 * present in the FWU metadata. 44 * 45 * return -1 on error, otherwise 0 46 ******************************************************************************/ 47 static int fwu_metadata_crc_check(void) 48 { 49 unsigned char *data = (unsigned char *)&metadata; 50 51 uint32_t calc_crc = tf_crc32(0U, data + sizeof(metadata.crc_32), 52 (sizeof(metadata) - 53 sizeof(metadata.crc_32))); 54 55 if (metadata.crc_32 != calc_crc) { 56 return -1; 57 } 58 59 return 0; 60 } 61 62 /******************************************************************************* 63 * Check the sanity of FWU metadata. 64 * 65 * return -EINVAL on error, otherwise 0 66 ******************************************************************************/ 67 static int fwu_metadata_sanity_check(void) 68 { 69 if (metadata.version != FWU_METADATA_VERSION) { 70 WARN("Incorrect FWU Metadata version of %u\n", 71 metadata.version); 72 return -EINVAL; 73 } 74 75 if (metadata.active_index >= NR_OF_FW_BANKS) { 76 WARN("Active Index value(%u) greater than the configured value(%d)", 77 metadata.active_index, NR_OF_FW_BANKS); 78 return -EINVAL; 79 } 80 81 if (metadata.previous_active_index >= NR_OF_FW_BANKS) { 82 WARN("Previous Active Index value(%u) greater than the configured value(%d)", 83 metadata.previous_active_index, NR_OF_FW_BANKS); 84 return -EINVAL; 85 } 86 87 #if PSA_FWU_METADATA_FW_STORE_DESC 88 if (metadata.fw_desc.num_banks != NR_OF_FW_BANKS) { 89 WARN("Number of Banks(%u) in FWU Metadata different from the configured value(%d)", 90 metadata.fw_desc.num_banks, NR_OF_FW_BANKS); 91 return -EINVAL; 92 } 93 94 if (metadata.fw_desc.num_images != NR_OF_IMAGES_IN_FW_BANK) { 95 WARN("Number of Images(%u) in FWU Metadata different from the configured value(%d)", 96 metadata.fw_desc.num_images, NR_OF_IMAGES_IN_FW_BANK); 97 return -EINVAL; 98 } 99 100 if (metadata.desc_offset != FWU_FW_STORE_DESC_OFFSET) { 101 WARN("Descriptor Offset(0x%x) in the FWU Metadata not equal to 0x20\n", 102 metadata.desc_offset); 103 return -EINVAL; 104 } 105 #else 106 if (metadata.desc_offset != 0U) { 107 WARN("Descriptor offset has non zero value of 0x%x\n", 108 metadata.desc_offset); 109 return -EINVAL; 110 } 111 #endif 112 113 return 0; 114 } 115 116 /******************************************************************************* 117 * Verify and load specified FWU metadata image to local FWU metadata structure. 118 * 119 * @image_id: FWU metadata image id (either FWU_METADATA_IMAGE_ID or 120 * BKUP_FWU_METADATA_IMAGE_ID) 121 * 122 * return a negative value on error, otherwise 0 123 ******************************************************************************/ 124 static int fwu_metadata_load(unsigned int image_id) 125 { 126 int result; 127 uintptr_t dev_handle, image_handle, image_spec; 128 size_t bytes_read; 129 130 assert((image_id == FWU_METADATA_IMAGE_ID) || 131 (image_id == BKUP_FWU_METADATA_IMAGE_ID)); 132 133 result = plat_fwu_set_metadata_image_source(image_id, 134 &dev_handle, 135 &image_spec); 136 if (result != 0) { 137 WARN("Failed to set reference to image id=%u (%i)\n", 138 image_id, result); 139 return result; 140 } 141 142 result = io_open(dev_handle, image_spec, &image_handle); 143 if (result != 0) { 144 WARN("Failed to load image id id=%u (%i)\n", 145 image_id, result); 146 return result; 147 } 148 149 result = io_read(image_handle, (uintptr_t)&metadata, 150 sizeof(struct fwu_metadata), &bytes_read); 151 152 if (result != 0) { 153 WARN("Failed to read image id=%u (%i)\n", image_id, result); 154 goto exit; 155 } 156 157 if (sizeof(struct fwu_metadata) != bytes_read) { 158 /* return -1 in case of partial/no read */ 159 result = -1; 160 WARN("Read bytes (%zu) instead of expected (%zu) bytes\n", 161 bytes_read, sizeof(struct fwu_metadata)); 162 goto exit; 163 } 164 165 /* sanity check on loaded parameters */ 166 result = fwu_metadata_sanity_check(); 167 if (result != 0) { 168 WARN("Sanity %s\n", "check failed on FWU metadata"); 169 goto exit; 170 } 171 172 /* CRC check on loaded parameters */ 173 result = fwu_metadata_crc_check(); 174 if (result != 0) { 175 WARN("CRC %s\n", "check failed on FWU metadata"); 176 } 177 178 exit: 179 (void)io_close(image_handle); 180 181 return result; 182 } 183 184 /******************************************************************************* 185 * Check for an alternate bank for the platform to boot from. This function will 186 * mostly be called whenever the count of the number of times a platform boots 187 * in the Trial State exceeds a pre-set limit. 188 * The function first checks if the platform can boot from the previously active 189 * bank. If not, it tries to find another bank in the accepted state. 190 * And finally, if both the checks fail, as a last resort, it tries to find 191 * a valid bank. 192 * 193 * Returns the index of a bank to boot, else returns invalid index 194 * INVALID_BOOT_IDX. 195 ******************************************************************************/ 196 uint32_t fwu_get_alternate_boot_bank(void) 197 { 198 uint32_t i; 199 200 /* First check if the previously active bank can be used */ 201 if (metadata.bank_state[metadata.previous_active_index] == 202 FWU_BANK_STATE_ACCEPTED) { 203 return metadata.previous_active_index; 204 } 205 206 /* Now check for any other bank in the accepted state */ 207 for (i = 0U; i < NR_OF_FW_BANKS; i++) { 208 if (i == metadata.active_index || 209 i == metadata.previous_active_index) { 210 continue; 211 } 212 213 if (metadata.bank_state[i] == FWU_BANK_STATE_ACCEPTED) { 214 return i; 215 } 216 } 217 218 /* 219 * No accepted bank found. Now try booting from a valid bank. 220 * Give priority to the previous active bank. 221 */ 222 if (metadata.bank_state[metadata.previous_active_index] == 223 FWU_BANK_STATE_VALID) { 224 return metadata.previous_active_index; 225 } 226 227 for (i = 0U; i < NR_OF_FW_BANKS; i++) { 228 if (i == metadata.active_index || 229 i == metadata.previous_active_index) { 230 continue; 231 } 232 233 if (metadata.bank_state[i] == FWU_BANK_STATE_VALID) { 234 return i; 235 } 236 } 237 238 return INVALID_BOOT_IDX; 239 } 240 241 /******************************************************************************* 242 * The platform can be in one of Valid, Invalid or Accepted states. 243 * 244 * Invalid - One or more images in the bank are corrupted, or partially 245 * overwritten. The bank is not to be used for booting. 246 * 247 * Valid - All images of the bank are valid but at least one image has not 248 * been accepted. This implies that the platform is in Trial State. 249 * 250 * Accepted - All images of the bank are valid and accepted. 251 * 252 * Returns the state of the current active bank 253 ******************************************************************************/ 254 uint32_t fwu_get_active_bank_state(void) 255 { 256 assert(is_metadata_initialized); 257 258 return metadata.bank_state[metadata.active_index]; 259 } 260 261 const struct fwu_metadata *fwu_get_metadata(void) 262 { 263 assert(is_metadata_initialized); 264 265 return &metadata; 266 } 267 268 /******************************************************************************* 269 * Load verified copy of FWU metadata image kept in the platform NV storage 270 * into local FWU metadata structure. 271 * Also, update platform I/O policies with the offset address and length of 272 * firmware-updated images kept in the platform NV storage. 273 ******************************************************************************/ 274 void fwu_init(void) 275 { 276 /* Load FWU metadata which will be used to load the images in the 277 * active bank as per PSA FWU specification 278 */ 279 int result = fwu_metadata_load(FWU_METADATA_IMAGE_ID); 280 281 if (result != 0) { 282 WARN("loading of FWU-Metadata failed, " 283 "using Bkup-FWU-Metadata\n"); 284 285 result = fwu_metadata_load(BKUP_FWU_METADATA_IMAGE_ID); 286 if (result != 0) { 287 ERROR("loading of Bkup-FWU-Metadata failed\n"); 288 panic(); 289 } 290 } 291 292 is_metadata_initialized = true; 293 294 plat_fwu_set_images_source(&metadata); 295 } 296