1 /*
2  * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 
9 #include <common/debug.h>
10 #include <lib/optee_utils.h>
11 
12 /*
13  * load_addr_hi and load_addr_lo: image load address.
14  * image_id: 0 - pager, 1 - paged
15  * size: image size in bytes.
16  */
17 typedef struct optee_image {
18 	uint32_t load_addr_hi;
19 	uint32_t load_addr_lo;
20 	uint32_t image_id;
21 	uint32_t size;
22 } optee_image_t;
23 
24 #define OPTEE_PAGER_IMAGE_ID		0
25 #define OPTEE_PAGED_IMAGE_ID		1
26 
27 #define OPTEE_MAX_NUM_IMAGES		2u
28 
29 #define TEE_MAGIC_NUM_OPTEE		0x4554504f
30 /*
31  * magic: header magic number.
32  * version: OPTEE header version:
33  *		1 - not supported
34  *		2 - supported
35  * arch: OPTEE os architecture type: 0 - AARCH32, 1 - AARCH64.
36  * flags: unused currently.
37  * nb_images: number of images.
38  */
39 typedef struct optee_header {
40 	uint32_t magic;
41 	uint8_t version;
42 	uint8_t arch;
43 	uint16_t flags;
44 	uint32_t nb_images;
45 	optee_image_t optee_image_list[];
46 } optee_header_t;
47 
48 /*******************************************************************************
49  * Check if it is a valid tee header
50  * Return true if valid
51  * Return false if invalid
52  ******************************************************************************/
tee_validate_header(optee_header_t * header)53 static bool tee_validate_header(optee_header_t *header)
54 {
55 	if ((header->magic == TEE_MAGIC_NUM_OPTEE) &&
56 		(header->version == 2u) &&
57 		(header->nb_images > 0u) &&
58 		(header->nb_images <= OPTEE_MAX_NUM_IMAGES)) {
59 		return true;
60 	}
61 
62 	return false;
63 }
64 
optee_header_is_valid(uintptr_t header_base)65 bool optee_header_is_valid(uintptr_t header_base)
66 {
67 	return tee_validate_header((optee_header_t *)header_base);
68 }
69 
70 /*******************************************************************************
71  * Parse the OPTEE image
72  * Return 0 on success or a negative error code otherwise.
73  ******************************************************************************/
parse_optee_image(image_info_t * image_info,optee_image_t * image)74 static int parse_optee_image(image_info_t *image_info,
75 		optee_image_t *image)
76 {
77 	uintptr_t init_load_addr, free_end, requested_end;
78 	size_t init_size;
79 
80 	init_load_addr = ((uint64_t)image->load_addr_hi << 32) |
81 					image->load_addr_lo;
82 	init_size = image->size;
83 
84 	/*
85 	 * image->load_addr_hi & image->load_addr_lo set to UINT32_MAX indicate
86 	 * loader decided address; take our pre-mapped area for current image
87 	 * since arm-tf could not allocate memory dynamically
88 	 */
89 	if ((image->load_addr_hi == UINT32_MAX) &&
90 	    (image->load_addr_lo == UINT32_MAX)) {
91 		init_load_addr = image_info->image_base;
92 	}
93 
94 	/* Check that the default end address doesn't overflow */
95 	if (check_uptr_overflow(image_info->image_base,
96 				image_info->image_max_size - 1))
97 		return -1;
98 	free_end = image_info->image_base + (image_info->image_max_size - 1);
99 
100 	/* Check that the image end address doesn't overflow */
101 	if (check_uptr_overflow(init_load_addr, init_size - 1))
102 		return -1;
103 	requested_end = init_load_addr + (init_size - 1);
104 	/*
105 	 * Check that the requested RAM location is within reserved
106 	 * space for OPTEE.
107 	 */
108 	if (!((init_load_addr >= image_info->image_base) &&
109 			(requested_end <= free_end))) {
110 		WARN("The load address in optee header %p - %p is not in reserved area: %p - %p.\n",
111 				(void *)init_load_addr,
112 				(void *)(init_load_addr + init_size),
113 				(void *)image_info->image_base,
114 				(void *)(image_info->image_base +
115 					image_info->image_max_size));
116 		return -1;
117 	}
118 
119 	/*
120 	 * Remove the skip attr from image_info, the image will be loaded.
121 	 * The default attr in image_info is "IMAGE_ATTRIB_SKIP_LOADING", which
122 	 * mean the image will not be loaded. Here, we parse the header image to
123 	 * know that the extra image need to be loaded, so remove the skip attr.
124 	 */
125 	image_info->h.attr &= ~IMAGE_ATTRIB_SKIP_LOADING;
126 
127 	/* Update image base and size of image_info */
128 	image_info->image_base = init_load_addr;
129 	image_info->image_size = init_size;
130 
131 	return 0;
132 }
133 
134 /*******************************************************************************
135  * Parse the OPTEE header
136  * Return 0 on success or a negative error code otherwise.
137  ******************************************************************************/
parse_optee_header(entry_point_info_t * header_ep,image_info_t * pager_image_info,image_info_t * paged_image_info)138 int parse_optee_header(entry_point_info_t *header_ep,
139 		image_info_t *pager_image_info,
140 		image_info_t *paged_image_info)
141 
142 {
143 	optee_header_t *header;
144 	uint32_t num;
145 	int ret;
146 
147 	assert(header_ep);
148 	header = (optee_header_t *)header_ep->pc;
149 	assert(header);
150 
151 	/* Print the OPTEE header information */
152 	INFO("OPTEE ep=0x%x\n", (unsigned int)header_ep->pc);
153 	INFO("OPTEE header info:\n");
154 	INFO("      magic=0x%x\n", header->magic);
155 	INFO("      version=0x%x\n", header->version);
156 	INFO("      arch=0x%x\n", header->arch);
157 	INFO("      flags=0x%x\n", header->flags);
158 	INFO("      nb_images=0x%x\n", header->nb_images);
159 
160 	/*
161 	 * OPTEE image has 3 types:
162 	 *
163 	 * 1. Plain OPTEE bin without header.
164 	 *	Original bin without header, return directly,
165 	 *	BL32_EXTRA1_IMAGE_ID and BL32_EXTRA2_IMAGE_ID will be skipped.
166 	 *
167 	 * 2. OPTEE bin with header bin, but no paging.
168 	 *	Header available and nb_images = 1, remove skip attr for
169 	 *	BL32_EXTRA1_IMAGE_ID. BL32_EXTRA1_IMAGE_ID will be loaded,
170 	 *	and BL32_EXTRA2_IMAGE_ID be skipped.
171 	 *
172 	 * 3. OPTEE image with paging support.
173 	 *	Header available and nb_images = 2, there are 3 bins: header,
174 	 *	pager and pageable. Remove skip attr for BL32_EXTRA1_IMAGE_ID
175 	 *	and BL32_EXTRA2_IMAGE_ID to load pager and paged bin.
176 	 */
177 	if (!tee_validate_header(header)) {
178 		INFO("Invalid OPTEE header, set legacy mode.\n");
179 #ifdef __aarch64__
180 		header_ep->args.arg0 = MODE_RW_64;
181 #else
182 		header_ep->args.arg0 = MODE_RW_32;
183 #endif
184 		return 0;
185 	}
186 
187 	/* Parse OPTEE image */
188 	for (num = 0U; num < header->nb_images; num++) {
189 		if (header->optee_image_list[num].image_id ==
190 				OPTEE_PAGER_IMAGE_ID) {
191 			ret = parse_optee_image(pager_image_info,
192 				&header->optee_image_list[num]);
193 		} else if (header->optee_image_list[num].image_id ==
194 				OPTEE_PAGED_IMAGE_ID) {
195 			ret = parse_optee_image(paged_image_info,
196 				&header->optee_image_list[num]);
197 		} else {
198 			ERROR("Parse optee image failed.\n");
199 			return -1;
200 		}
201 
202 		if (ret != 0)
203 			return -1;
204 	}
205 
206 	/*
207 	 * Update "pc" value which should comes from pager image. After the
208 	 * header image is parsed, it will be unuseful, and the actual
209 	 * execution image after BL31 is pager image.
210 	 */
211 	header_ep->pc =	pager_image_info->image_base;
212 
213 	/*
214 	 * The paged load address and size are populated in
215 	 * header image arguments so that can be read by the
216 	 * BL32 SPD.
217 	 */
218 	header_ep->args.arg1 = paged_image_info->image_base;
219 	header_ep->args.arg2 = paged_image_info->image_size;
220 
221 	/* Set OPTEE runtime arch - aarch32/aarch64 */
222 	if (header->arch == 0) {
223 		header_ep->args.arg0 = MODE_RW_32;
224 	} else {
225 #ifdef __aarch64__
226 		header_ep->args.arg0 = MODE_RW_64;
227 #else
228 		ERROR("Cannot boot an AArch64 OP-TEE\n");
229 		return -1;
230 #endif
231 	}
232 
233 	return 0;
234 }
235