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