1 /*
2 * Copyright (c) 2018-2024, 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 #if CRYPTO_SUPPORT
12 #include <mbedtls/version.h>
13 #endif /* CRYPTO_SUPPORT */
14
15 #include <common/debug.h>
16 #include <common/desc_image_load.h>
17 #include <common/tbbr/tbbr_img_def.h>
18 #include <lib/fconf/fconf.h>
19 #include <lib/fconf/fconf_dyn_cfg_getter.h>
20 #include <lib/fconf/fconf_tbbr_getter.h>
21
22 #include <plat/arm/common/arm_dyn_cfg_helpers.h>
23 #include <plat/arm/common/plat_arm.h>
24 #include <platform_def.h>
25
26 #if CRYPTO_SUPPORT
27
28 static void *mbedtls_heap_addr;
29 static size_t mbedtls_heap_size;
30
31 /*
32 * This function is the implementation of the shared Mbed TLS heap between
33 * BL1 and BL2 for Arm platforms. The shared heap address is passed from BL1
34 * to BL2 with a pointer. This pointer resides inside the TB_FW_CONFIG file
35 * which is a DTB.
36 *
37 * This function is placed inside an #if directive for the below reasons:
38 * - To allocate space for the Mbed TLS heap --only if-- Trusted Board Boot
39 * is enabled.
40 * - This implementation requires the DTB to be present so that BL1 has a
41 * mechanism to pass the pointer to BL2.
42 */
arm_get_mbedtls_heap(void ** heap_addr,size_t * heap_size)43 int arm_get_mbedtls_heap(void **heap_addr, size_t *heap_size)
44 {
45 assert(heap_addr != NULL);
46 assert(heap_size != NULL);
47
48 #if defined(IMAGE_BL1) || RESET_TO_BL2 || defined(IMAGE_BL31)
49
50 /* If in BL1 or RESET_TO_BL2 define a heap */
51 static unsigned char heap[TF_MBEDTLS_HEAP_SIZE];
52
53 *heap_addr = heap;
54 *heap_size = sizeof(heap);
55 mbedtls_heap_addr = heap;
56 mbedtls_heap_size = sizeof(heap);
57
58 #elif defined(IMAGE_BL2)
59
60 /* If in BL2, retrieve the already allocated heap's info from DTB */
61 *heap_addr = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_addr);
62 *heap_size = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_size);
63
64 #endif
65
66 return 0;
67 }
68
69 /*
70 * Puts the shared Mbed TLS heap information to the DTB.
71 * Executed only from BL1.
72 */
arm_bl1_set_mbedtls_heap(void)73 void arm_bl1_set_mbedtls_heap(void)
74 {
75 int err;
76 uintptr_t tb_fw_cfg_dtb;
77 const struct dyn_cfg_dtb_info_t *tb_fw_config_info;
78
79 /*
80 * If tb_fw_cfg_dtb==NULL then DTB is not present for the current
81 * platform. As such, we don't attempt to write to the DTB at all.
82 *
83 * If mbedtls_heap_addr==NULL, then it means we are using the default
84 * heap implementation. As such, BL2 will have its own heap for sure
85 * and hence there is no need to pass any information to the DTB.
86 *
87 * In the latter case, if we still wanted to write in the DTB the heap
88 * information, we would need to call plat_get_mbedtls_heap to retrieve
89 * the default heap's address and size.
90 */
91
92 tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID);
93 assert(tb_fw_config_info != NULL);
94
95 tb_fw_cfg_dtb = tb_fw_config_info->config_addr;
96
97 if ((tb_fw_cfg_dtb != 0UL) && (mbedtls_heap_addr != NULL)) {
98 /* As libfdt uses void *, we can't avoid this cast */
99 void *dtb = (void *)tb_fw_cfg_dtb;
100
101 err = arm_set_dtb_mbedtls_heap_info(dtb,
102 mbedtls_heap_addr, mbedtls_heap_size);
103 if (err < 0) {
104 ERROR("%swrite shared Mbed TLS heap information%s",
105 "BL1: unable to ", " 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 a function which
115 * is called after heap information is written in the DTB.
116 */
117 flush_dcache_range(tb_fw_cfg_dtb, fdt_totalsize(dtb));
118 #endif /* !MEASURED_BOOT */
119 }
120 }
121 #endif /* CRYPTO_SUPPORT */
122
123 #if IMAGE_BL2
124 /*
125 * BL2 utility function to initialize dynamic configuration specified by
126 * FW_CONFIG. Populate the bl_mem_params_node_t of other FW_CONFIGs if
127 * specified in FW_CONFIG.
128 */
arm_bl2_dyn_cfg_init(void)129 void arm_bl2_dyn_cfg_init(void)
130 {
131 unsigned int i;
132 bl_mem_params_node_t *cfg_mem_params = NULL;
133 uintptr_t image_base;
134 uint32_t image_size;
135 unsigned int error_config_id = MAX_IMAGE_IDS;
136 const unsigned int config_ids[] = {
137 HW_CONFIG_ID,
138 SOC_FW_CONFIG_ID,
139 NT_FW_CONFIG_ID,
140 TOS_FW_CONFIG_ID
141 };
142
143 const struct dyn_cfg_dtb_info_t *dtb_info;
144
145 /* Iterate through all the fw config IDs */
146 for (i = 0; i < ARRAY_SIZE(config_ids); i++) {
147 /* Get the config load address and size */
148 cfg_mem_params = get_bl_mem_params_node(config_ids[i]);
149 if (cfg_mem_params == NULL) {
150 VERBOSE("%sconfig_id = %d in bl_mem_params_node\n",
151 "Couldn't find ", config_ids[i]);
152 continue;
153 }
154
155 dtb_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, config_ids[i]);
156 if (dtb_info == NULL) {
157 VERBOSE("%sconfig_id %d load info in FW_CONFIG\n",
158 "Couldn't find ", config_ids[i]);
159 continue;
160 }
161
162 image_base = dtb_info->config_addr;
163 image_size = dtb_info->config_max_size;
164
165 /*
166 * Do some runtime checks on the load addresses of soc_fw_config,
167 * tos_fw_config, nt_fw_config. This is not a comprehensive check
168 * of all invalid addresses but to prevent trivial porting errors.
169 */
170 if (config_ids[i] != HW_CONFIG_ID) {
171
172 if (check_uptr_overflow(image_base, image_size)) {
173 VERBOSE("%s=%d as its %s is overflowing uptr\n",
174 "skip loading of firmware config",
175 config_ids[i],
176 "load-address");
177 error_config_id = config_ids[i];
178 continue;
179 }
180 #ifdef BL31_BASE
181 /* Ensure the configs don't overlap with BL31 */
182 if ((image_base >= BL31_BASE) &&
183 (image_base <= BL31_LIMIT)) {
184 VERBOSE("%s=%d as its %s is overlapping BL31\n",
185 "skip loading of firmware config",
186 config_ids[i],
187 "load-address");
188 error_config_id = config_ids[i];
189 continue;
190 }
191 #endif
192 /* Ensure the configs are loaded in a valid address */
193 if (image_base < ARM_BL_RAM_BASE) {
194 VERBOSE("%s=%d as its %s is invalid\n",
195 "skip loading of firmware config",
196 config_ids[i],
197 "load-address");
198 error_config_id = config_ids[i];
199 continue;
200 }
201 #ifdef BL32_BASE
202 /*
203 * If BL32 is present, ensure that the configs don't
204 * overlap with it.
205 */
206 if ((image_base >= BL32_BASE) &&
207 (image_base <= BL32_LIMIT)) {
208 VERBOSE("%s=%d as its %s is overlapping BL32\n",
209 "skip loading of firmware config",
210 config_ids[i],
211 "load-address");
212 error_config_id = config_ids[i];
213 continue;
214 }
215 #endif
216 }
217
218 cfg_mem_params->image_info.image_base = image_base;
219 cfg_mem_params->image_info.image_max_size = (uint32_t)image_size;
220
221 /*
222 * Remove the IMAGE_ATTRIB_SKIP_LOADING attribute from
223 * HW_CONFIG or FW_CONFIG nodes
224 */
225 cfg_mem_params->image_info.h.attr &= ~IMAGE_ATTRIB_SKIP_LOADING;
226 }
227
228 if (error_config_id != MAX_IMAGE_IDS) {
229 ERROR("Invalid config file %u\n", error_config_id);
230 panic();
231 }
232 }
233 #endif /* IMAGE_BL2 */
234