1 /*
2 * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
3 * Copyright (c) 2021-2025, Renesas Electronics Corporation. All rights reserved.
4 *
5 * SPDX-License-Identifier: BSD-3-Clause
6 */
7
8 #include <assert.h>
9 #include <errno.h>
10 #include <string.h>
11
12 #include <arch.h>
13 #include <arch_features.h>
14 #include <arch_helpers.h>
15 #include <common/bl_common.h>
16 #include <common/build_message.h>
17 #include <common/debug.h>
18 #include <drivers/auth/auth_mod.h>
19 #include <drivers/io/io_storage.h>
20 #include <lib/utils.h>
21 #include <lib/xlat_tables/xlat_tables_defs.h>
22 #include <plat/common/platform.h>
23
24 #if TRUSTED_BOARD_BOOT
25 # ifdef DYN_DISABLE_AUTH
26 static int disable_auth;
27
28 /******************************************************************************
29 * API to dynamically disable authentication. Only meant for development
30 * systems. This is only invoked if DYN_DISABLE_AUTH is defined.
31 *****************************************************************************/
dyn_disable_auth(void)32 void dyn_disable_auth(void)
33 {
34 INFO("Disabling authentication of images dynamically\n");
35 disable_auth = 1;
36 }
37 # endif /* DYN_DISABLE_AUTH */
38
39 /******************************************************************************
40 * Function to determine whether the authentication is disabled dynamically.
41 *****************************************************************************/
dyn_is_auth_disabled(void)42 static int dyn_is_auth_disabled(void)
43 {
44 # ifdef DYN_DISABLE_AUTH
45 return disable_auth;
46 # else
47 return 0;
48 # endif
49 }
50 #endif /* TRUSTED_BOARD_BOOT */
51
page_align(uintptr_t value,unsigned dir)52 uintptr_t page_align(uintptr_t value, unsigned dir)
53 {
54 /* Round up the limit to the next page boundary */
55 if ((value & PAGE_SIZE_MASK) != 0U) {
56 value &= ~PAGE_SIZE_MASK;
57 if (dir == UP) {
58 value += PAGE_SIZE;
59 }
60 }
61
62 return value;
63 }
64
65 /*******************************************************************************
66 * Internal function to load an image at a specific address given
67 * an image ID and extents of free memory.
68 *
69 * If the load is successful then the image information is updated.
70 *
71 * Returns 0 on success, a negative error code otherwise.
72 ******************************************************************************/
load_image(unsigned int image_id,image_info_t * image_data)73 static int load_image(unsigned int image_id, image_info_t *image_data)
74 {
75 uintptr_t dev_handle = 0ULL;
76 uintptr_t image_handle = 0ULL;
77 uintptr_t image_spec = 0ULL;
78 uintptr_t image_base;
79 size_t image_size = 0ULL;
80 size_t bytes_read = 0ULL;
81 int io_result;
82
83 assert(image_data != NULL);
84 assert(image_data->h.version >= VERSION_2);
85
86 image_base = image_data->image_base;
87
88 /* Obtain a reference to the image by querying the platform layer */
89 io_result = plat_get_image_source(image_id, &dev_handle, &image_spec);
90 if (io_result != 0) {
91 WARN("Failed to obtain reference to image id=%u (%i)\n",
92 image_id, io_result);
93 return io_result;
94 }
95
96 /* Attempt to access the image */
97 io_result = io_open(dev_handle, image_spec, &image_handle);
98 if (io_result != 0) {
99 WARN("Failed to access image id=%u (%i)\n",
100 image_id, io_result);
101 return io_result;
102 }
103
104 INFO("Loading image id=%u at address 0x%lx\n", image_id, image_base);
105
106 /* Find the size of the image */
107 io_result = io_size(image_handle, &image_size);
108 if (io_result != 0) {
109 WARN("Failed to determine the size of the image id=%u (%i)\n",
110 image_id, io_result);
111 goto exit_load_image;
112 }
113
114 if (image_size == 0U) {
115 WARN("image id=%u size is zero\n", image_id);
116 io_result = -EIO;
117 goto exit_load_image;
118 }
119
120 /* Check that the image size to load is within limit */
121 if (image_size > image_data->image_max_size) {
122 WARN("Image id=%u size out of bounds\n", image_id);
123 io_result = -EFBIG;
124 goto exit_load_image;
125 }
126
127 /*
128 * image_data->image_max_size is a uint32_t so image_size will always
129 * fit in image_data->image_size.
130 */
131 image_data->image_size = (uint32_t)image_size;
132
133 /* We have enough space so load the image now */
134 /* TODO: Consider whether to try to recover/retry a partially successful read */
135 io_result = io_read(image_handle, image_base, image_size, &bytes_read);
136 if ((io_result != 0) || (bytes_read < image_size)) {
137 WARN("Failed to load image id=%u (%i)\n", image_id, io_result);
138 goto exit_load_image;
139 }
140
141 INFO("Image id=%u loaded: 0x%lx - 0x%lx\n", image_id, image_base,
142 (uintptr_t)(image_base + image_size));
143
144 exit_load_image:
145 (void)io_close(image_handle);
146 /* Ignore improbable/unrecoverable error in 'close' */
147
148 /* TODO: Consider maintaining open device connection from this bootloader stage */
149 (void)io_dev_close(dev_handle);
150 /* Ignore improbable/unrecoverable error in 'dev_close' */
151
152 return io_result;
153 }
154
155 #if TRUSTED_BOARD_BOOT
156 /*
157 * This function uses recursion to authenticate the parent images up to the root
158 * of trust.
159 */
load_auth_image_recursive(unsigned int image_id,image_info_t * image_data)160 static int load_auth_image_recursive(unsigned int image_id,
161 image_info_t *image_data)
162 {
163 int rc;
164 unsigned int parent_id;
165
166 /* Use recursion to authenticate parent images */
167 rc = auth_mod_get_parent_id(image_id, &parent_id);
168 if (rc == 0) {
169 rc = load_auth_image_recursive(parent_id, image_data);
170 if (rc != 0) {
171 return rc;
172 }
173 }
174
175 /* Load the image */
176 rc = load_image(image_id, image_data);
177 if (rc != 0) {
178 return rc;
179 }
180
181 /* Authenticate it */
182 rc = auth_mod_verify_img(image_id,
183 (void *)image_data->image_base,
184 image_data->image_size);
185 if (rc != 0) {
186 /* Authentication error, zero memory and flush it right away. */
187 zero_normalmem((void *)image_data->image_base,
188 image_data->image_size);
189 flush_dcache_range(image_data->image_base,
190 image_data->image_size);
191 return -EAUTH;
192 }
193
194 return 0;
195 }
196 #endif /* TRUSTED_BOARD_BOOT */
197
load_auth_image_internal(unsigned int image_id,image_info_t * image_data)198 static int load_auth_image_internal(unsigned int image_id,
199 image_info_t *image_data)
200 {
201 #if TRUSTED_BOARD_BOOT
202 if (dyn_is_auth_disabled() == 0) {
203 return load_auth_image_recursive(image_id, image_data);
204 }
205 #endif
206
207 return load_image(image_id, image_data);
208 }
209
210 /*******************************************************************************
211 * Generic function to load and authenticate an image. The image is actually
212 * loaded by calling the 'load_image()' function. Therefore, it returns the
213 * same error codes if the loading operation failed, or -EAUTH if the
214 * authentication failed. In addition, this function uses recursion to
215 * authenticate the parent images up to the root of trust (if TBB is enabled).
216 ******************************************************************************/
load_auth_image(unsigned int image_id,image_info_t * image_data)217 int load_auth_image(unsigned int image_id, image_info_t *image_data)
218 {
219 int err;
220
221 if ((plat_try_img_ops == NULL) || (plat_try_img_ops->next_instance == NULL)) {
222 err = load_auth_image_internal(image_id, image_data);
223 } else {
224 do {
225 err = load_auth_image_internal(image_id, image_data);
226 if (err != 0) {
227 if (plat_try_img_ops->next_instance(image_id) != 0) {
228 return err;
229 }
230 }
231 } while (err != 0);
232 }
233
234 if (err == 0) {
235 /*
236 * If loading of the image gets passed (along with its
237 * authentication in case of Trusted-Boot flow) then measure
238 * it (if MEASURED_BOOT flag is enabled).
239 */
240 err = plat_mboot_measure_image(image_id, image_data);
241 if (err != 0) {
242 return err;
243 }
244
245 /*
246 * Flush the image to main memory so that it can be executed
247 * later by any CPU, regardless of cache and MMU state.
248 */
249 flush_dcache_range(image_data->image_base,
250 image_data->image_size);
251 }
252
253 return err;
254 }
255
256 /*******************************************************************************
257 * Print the content of an entry_point_info_t structure.
258 ******************************************************************************/
print_entry_point_info(const entry_point_info_t * ep_info)259 void print_entry_point_info(const entry_point_info_t *ep_info)
260 {
261 INFO("Entry point address = 0x%lx\n", ep_info->pc);
262 INFO("SPSR = 0x%x\n", ep_info->spsr);
263
264 #define PRINT_IMAGE_ARG(n) \
265 VERBOSE("Argument #" #n " = 0x%llx\n", \
266 (unsigned long long) ep_info->args.arg##n)
267
268 PRINT_IMAGE_ARG(0);
269 PRINT_IMAGE_ARG(1);
270 PRINT_IMAGE_ARG(2);
271 PRINT_IMAGE_ARG(3);
272 #ifdef __aarch64__
273 PRINT_IMAGE_ARG(4);
274 PRINT_IMAGE_ARG(5);
275 PRINT_IMAGE_ARG(6);
276 PRINT_IMAGE_ARG(7);
277 #endif
278 #undef PRINT_IMAGE_ARG
279 }
280
281 /*
282 * This function is for returning the TF-A version
283 */
get_version(void)284 const char *get_version(void)
285 {
286 return build_version;
287 }
288