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 tb_fw_cfg_dtb = tb_fw_config_info->config_addr; 97 98 if ((tb_fw_cfg_dtb != 0UL) && (mbedtls_heap_addr != NULL)) { 99 /* As libfdt use void *, we can't avoid this cast */ 100 void *dtb = (void *)tb_fw_cfg_dtb; 101 102 err = arm_set_dtb_mbedtls_heap_info(dtb, 103 mbedtls_heap_addr, mbedtls_heap_size); 104 if (err < 0) { 105 ERROR("BL1: unable to write shared Mbed TLS heap information to DTB\n"); 106 panic(); 107 } 108 #if !MEASURED_BOOT 109 /* 110 * Ensure that the info written to the DTB is visible to other 111 * images. It's critical because BL2 won't be able to proceed 112 * without the heap info. 113 * 114 * In MEASURED_BOOT case flushing is done in 115 * arm_bl1_set_bl2_hash() function which is called after heap 116 * information is written in the DTB. 117 */ 118 flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize(dtb)); 119 #endif /* !MEASURED_BOOT */ 120 } 121 } 122 123 #if MEASURED_BOOT 124 /* 125 * Puts the BL2 hash data to TB_FW_CONFIG DTB. 126 * Executed only from BL1. 127 */ 128 void arm_bl1_set_bl2_hash(image_desc_t *image_desc) 129 { 130 unsigned char hash_data[MBEDTLS_MD_MAX_SIZE]; 131 image_info_t image_info = image_desc->image_info; 132 uintptr_t tb_fw_cfg_dtb; 133 int err; 134 const struct dyn_cfg_dtb_info_t *tb_fw_config_info; 135 136 tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID); 137 tb_fw_cfg_dtb = tb_fw_config_info->config_addr; 138 139 /* 140 * If tb_fw_cfg_dtb==NULL then DTB is not present for the current 141 * platform. As such, we cannot write to the DTB at all and pass 142 * measured data. 143 */ 144 if (tb_fw_cfg_dtb == 0UL) { 145 panic(); 146 } 147 148 /* Calculate hash */ 149 err = crypto_mod_calc_hash(MBEDTLS_MD_ID, 150 (void *)image_info.image_base, 151 image_info.image_size, hash_data); 152 if (err != 0) { 153 ERROR("BL1: unable to calculate BL2 hash\n"); 154 panic(); 155 } 156 157 err = arm_set_bl2_hash_info((void *)tb_fw_cfg_dtb, hash_data); 158 if (err < 0) { 159 ERROR("BL1: unable to write BL2 hash data to DTB\n"); 160 panic(); 161 } 162 163 /* 164 * Ensure that the info written to the DTB is visible to other 165 * images. It's critical because BL2 won't be able to proceed 166 * without the heap info and its hash data. 167 */ 168 flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize((void *)tb_fw_cfg_dtb)); 169 } 170 #endif /* MEASURED_BOOT */ 171 #endif /* TRUSTED_BOARD_BOOT */ 172 173 /* 174 * BL2 utility function to initialize dynamic configuration specified by 175 * FW_CONFIG. Populate the bl_mem_params_node_t of other FW_CONFIGs if 176 * specified in FW_CONFIG. 177 */ 178 void arm_bl2_dyn_cfg_init(void) 179 { 180 unsigned int i; 181 bl_mem_params_node_t *cfg_mem_params = NULL; 182 uintptr_t image_base; 183 size_t image_size; 184 const unsigned int config_ids[] = { 185 HW_CONFIG_ID, 186 SOC_FW_CONFIG_ID, 187 NT_FW_CONFIG_ID, 188 #if defined(SPD_tspd) || defined(SPD_spmd) 189 /* tos_fw_config is only present for TSPD/SPMD */ 190 TOS_FW_CONFIG_ID 191 #endif 192 }; 193 194 const struct dyn_cfg_dtb_info_t *dtb_info; 195 196 /* Iterate through all the fw config IDs */ 197 for (i = 0; i < ARRAY_SIZE(config_ids); i++) { 198 /* Get the config load address and size from TB_FW_CONFIG */ 199 cfg_mem_params = get_bl_mem_params_node(config_ids[i]); 200 if (cfg_mem_params == NULL) { 201 VERBOSE("Couldn't find HW_CONFIG in bl_mem_params_node\n"); 202 continue; 203 } 204 205 dtb_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, config_ids[i]); 206 if (dtb_info == NULL) { 207 VERBOSE("Couldn't find config_id %d load info in TB_FW_CONFIG\n", 208 config_ids[i]); 209 continue; 210 } 211 212 image_base = dtb_info->config_addr; 213 image_size = dtb_info->config_max_size; 214 215 /* 216 * Do some runtime checks on the load addresses of soc_fw_config, 217 * tos_fw_config, nt_fw_config. This is not a comprehensive check 218 * of all invalid addresses but to prevent trivial porting errors. 219 */ 220 if (config_ids[i] != HW_CONFIG_ID) { 221 222 if (check_uptr_overflow(image_base, image_size)) 223 continue; 224 225 #ifdef BL31_BASE 226 /* Ensure the configs don't overlap with BL31 */ 227 if ((image_base >= BL31_BASE) && 228 (image_base <= BL31_LIMIT)) 229 continue; 230 #endif 231 /* Ensure the configs are loaded in a valid address */ 232 if (image_base < ARM_BL_RAM_BASE) 233 continue; 234 #ifdef BL32_BASE 235 /* 236 * If BL32 is present, ensure that the configs don't 237 * overlap with it. 238 */ 239 if ((image_base >= BL32_BASE) && 240 (image_base <= BL32_LIMIT)) 241 continue; 242 #endif 243 } 244 245 246 cfg_mem_params->image_info.image_base = image_base; 247 cfg_mem_params->image_info.image_max_size = (uint32_t)image_size; 248 249 /* 250 * Remove the IMAGE_ATTRIB_SKIP_LOADING attribute from 251 * HW_CONFIG or FW_CONFIG nodes 252 */ 253 cfg_mem_params->image_info.h.attr &= ~IMAGE_ATTRIB_SKIP_LOADING; 254 } 255 } 256