1 /* 2 * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <string.h> 9 #include <libfdt.h> 10 11 #include <platform_def.h> 12 13 #include <common/debug.h> 14 #include <common/desc_image_load.h> 15 #include <common/tbbr/tbbr_img_def.h> 16 #if TRUSTED_BOARD_BOOT 17 #include <drivers/auth/mbedtls/mbedtls_config.h> 18 #if MEASURED_BOOT 19 #include <drivers/auth/crypto_mod.h> 20 #include <mbedtls/md.h> 21 #endif 22 #endif 23 #include <lib/fconf/fconf.h> 24 #include <lib/fconf/fconf_dyn_cfg_getter.h> 25 #include <lib/fconf/fconf_tbbr_getter.h> 26 27 #include <plat/arm/common/arm_dyn_cfg_helpers.h> 28 #include <plat/arm/common/plat_arm.h> 29 30 #if TRUSTED_BOARD_BOOT 31 32 static void *mbedtls_heap_addr; 33 static size_t mbedtls_heap_size; 34 35 /* 36 * This function is the implementation of the shared Mbed TLS heap between 37 * BL1 and BL2 for Arm platforms. The shared heap address is passed from BL1 38 * to BL2 with a pointer. This pointer resides inside the TB_FW_CONFIG file 39 * which is a DTB. 40 * 41 * This function is placed inside an #if directive for the below reasons: 42 * - To allocate space for the Mbed TLS heap --only if-- Trusted Board Boot 43 * is enabled. 44 * - This implementation requires the DTB to be present so that BL1 has a 45 * mechanism to pass the pointer to BL2. 46 */ 47 int arm_get_mbedtls_heap(void **heap_addr, size_t *heap_size) 48 { 49 assert(heap_addr != NULL); 50 assert(heap_size != NULL); 51 52 #if defined(IMAGE_BL1) || BL2_AT_EL3 53 54 /* If in BL1 or BL2_AT_EL3 define a heap */ 55 static unsigned char heap[TF_MBEDTLS_HEAP_SIZE]; 56 57 *heap_addr = heap; 58 *heap_size = sizeof(heap); 59 mbedtls_heap_addr = heap; 60 mbedtls_heap_size = sizeof(heap); 61 62 #elif defined(IMAGE_BL2) 63 64 /* If in BL2, retrieve the already allocated heap's info from DTB */ 65 *heap_addr = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_addr); 66 *heap_size = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_size); 67 68 #endif 69 70 return 0; 71 } 72 73 /* 74 * Puts the shared Mbed TLS heap information to the DTB. 75 * Executed only from BL1. 76 */ 77 void arm_bl1_set_mbedtls_heap(void) 78 { 79 int err; 80 uintptr_t tb_fw_cfg_dtb; 81 const struct dyn_cfg_dtb_info_t *tb_fw_config_info; 82 83 /* 84 * If tb_fw_cfg_dtb==NULL then DTB is not present for the current 85 * platform. As such, we don't attempt to write to the DTB at all. 86 * 87 * If mbedtls_heap_addr==NULL, then it means we are using the default 88 * heap implementation. As such, BL2 will have its own heap for sure 89 * and hence there is no need to pass any information to the DTB. 90 * 91 * In the latter case, if we still wanted to write in the DTB the heap 92 * information, we would need to call plat_get_mbedtls_heap to retrieve 93 * the default heap's address and size. 94 */ 95 96 tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID); 97 assert(tb_fw_config_info != NULL); 98 99 tb_fw_cfg_dtb = tb_fw_config_info->config_addr; 100 101 if ((tb_fw_cfg_dtb != 0UL) && (mbedtls_heap_addr != NULL)) { 102 /* As libfdt uses void *, we can't avoid this cast */ 103 void *dtb = (void *)tb_fw_cfg_dtb; 104 105 err = arm_set_dtb_mbedtls_heap_info(dtb, 106 mbedtls_heap_addr, mbedtls_heap_size); 107 if (err < 0) { 108 ERROR("%swrite shared Mbed TLS heap information%s", 109 "BL1: unable to ", " to DTB\n"); 110 panic(); 111 } 112 #if !MEASURED_BOOT 113 /* 114 * Ensure that the info written to the DTB is visible to other 115 * images. It's critical because BL2 won't be able to proceed 116 * without the heap info. 117 * 118 * In MEASURED_BOOT case flushing is done in 119 * arm_bl1_set_bl2_hash() function which is called after heap 120 * information is written in the DTB. 121 */ 122 flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize(dtb)); 123 #endif /* !MEASURED_BOOT */ 124 } 125 } 126 127 #if MEASURED_BOOT 128 /* 129 * Calculates and writes BL2 hash data to TB_FW_CONFIG DTB. 130 * Executed only from BL1. 131 */ 132 void arm_bl1_set_bl2_hash(const image_desc_t *image_desc) 133 { 134 unsigned char hash_data[MBEDTLS_MD_MAX_SIZE]; 135 const image_info_t image_info = image_desc->image_info; 136 uintptr_t tb_fw_cfg_dtb; 137 int err; 138 const struct dyn_cfg_dtb_info_t *tb_fw_config_info; 139 140 tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID); 141 assert(tb_fw_config_info != NULL); 142 143 tb_fw_cfg_dtb = tb_fw_config_info->config_addr; 144 145 /* 146 * If tb_fw_cfg_dtb==NULL then DTB is not present for the current 147 * platform. As such, we cannot write to the DTB at all and pass 148 * measured data. 149 */ 150 if (tb_fw_cfg_dtb == 0UL) { 151 panic(); 152 } 153 154 /* Calculate hash */ 155 err = crypto_mod_calc_hash(MBEDTLS_MD_ID, 156 (void *)image_info.image_base, 157 image_info.image_size, hash_data); 158 if (err != 0) { 159 ERROR("%scalculate%s\n", "BL1: unable to ", 160 " BL2 hash"); 161 panic(); 162 } 163 164 err = arm_set_bl2_hash_info((void *)tb_fw_cfg_dtb, hash_data); 165 if (err < 0) { 166 ERROR("%swrite%sdata%s\n", "BL1: unable to ", 167 " BL2 hash ", "to DTB\n"); 168 panic(); 169 } 170 171 /* 172 * Ensure that the info written to the DTB is visible to other 173 * images. It's critical because BL2 won't be able to proceed 174 * without the heap info and its hash data. 175 */ 176 flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize((void *)tb_fw_cfg_dtb)); 177 } 178 179 /* 180 * Reads TCG_DIGEST_SIZE bytes of BL2 hash data from the DTB. 181 * Executed only from BL2. 182 */ 183 void arm_bl2_get_hash(void *data) 184 { 185 const void *bl2_hash; 186 187 assert(data != NULL); 188 189 /* Retrieve TCG_DIGEST_SIZE bytes of BL2 hash data from the DTB */ 190 bl2_hash = FCONF_GET_PROPERTY(tbbr, dyn_config, bl2_hash_data); 191 (void)memcpy(data, bl2_hash, TCG_DIGEST_SIZE); 192 } 193 #endif /* MEASURED_BOOT */ 194 #endif /* TRUSTED_BOARD_BOOT */ 195 196 /* 197 * BL2 utility function to initialize dynamic configuration specified by 198 * FW_CONFIG. Populate the bl_mem_params_node_t of other FW_CONFIGs if 199 * specified in FW_CONFIG. 200 */ 201 void arm_bl2_dyn_cfg_init(void) 202 { 203 unsigned int i; 204 bl_mem_params_node_t *cfg_mem_params = NULL; 205 uintptr_t image_base; 206 uint32_t image_size; 207 const unsigned int config_ids[] = { 208 HW_CONFIG_ID, 209 SOC_FW_CONFIG_ID, 210 NT_FW_CONFIG_ID, 211 #if defined(SPD_tspd) || defined(SPD_spmd) 212 /* tos_fw_config is only present for TSPD/SPMD */ 213 TOS_FW_CONFIG_ID 214 #endif 215 }; 216 217 const struct dyn_cfg_dtb_info_t *dtb_info; 218 219 /* Iterate through all the fw config IDs */ 220 for (i = 0; i < ARRAY_SIZE(config_ids); i++) { 221 /* Get the config load address and size from TB_FW_CONFIG */ 222 cfg_mem_params = get_bl_mem_params_node(config_ids[i]); 223 if (cfg_mem_params == NULL) { 224 VERBOSE("%sHW_CONFIG in bl_mem_params_node\n", 225 "Couldn't find "); 226 continue; 227 } 228 229 dtb_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, config_ids[i]); 230 if (dtb_info == NULL) { 231 VERBOSE("%sconfig_id %d load info in TB_FW_CONFIG\n", 232 "Couldn't find ", config_ids[i]); 233 continue; 234 } 235 236 image_base = dtb_info->config_addr; 237 image_size = dtb_info->config_max_size; 238 239 /* 240 * Do some runtime checks on the load addresses of soc_fw_config, 241 * tos_fw_config, nt_fw_config. This is not a comprehensive check 242 * of all invalid addresses but to prevent trivial porting errors. 243 */ 244 if (config_ids[i] != HW_CONFIG_ID) { 245 246 if (check_uptr_overflow(image_base, image_size)) { 247 continue; 248 } 249 #ifdef BL31_BASE 250 /* Ensure the configs don't overlap with BL31 */ 251 if ((image_base >= BL31_BASE) && 252 (image_base <= BL31_LIMIT)) { 253 continue; 254 } 255 #endif 256 /* Ensure the configs are loaded in a valid address */ 257 if (image_base < ARM_BL_RAM_BASE) { 258 continue; 259 } 260 #ifdef BL32_BASE 261 /* 262 * If BL32 is present, ensure that the configs don't 263 * overlap with it. 264 */ 265 if ((image_base >= BL32_BASE) && 266 (image_base <= BL32_LIMIT)) { 267 continue; 268 } 269 #endif 270 } 271 272 cfg_mem_params->image_info.image_base = image_base; 273 cfg_mem_params->image_info.image_max_size = (uint32_t)image_size; 274 275 /* 276 * Remove the IMAGE_ATTRIB_SKIP_LOADING attribute from 277 * HW_CONFIG or FW_CONFIG nodes 278 */ 279 cfg_mem_params->image_info.h.attr &= ~IMAGE_ATTRIB_SKIP_LOADING; 280 } 281 } 282