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1 | /* |
2 | * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. | |
3 | * | |
1a459660 | 4 | * SPDX-License-Identifier: GPL-2.0+ |
84cd9327 GB |
5 | */ |
6 | ||
7 | #include <cbfs.h> | |
8 | #include <malloc.h> | |
9 | #include <asm/byteorder.h> | |
10 | ||
11 | enum cbfs_result file_cbfs_result; | |
12 | ||
13 | const char *file_cbfs_error(void) | |
14 | { | |
15 | switch (file_cbfs_result) { | |
16 | case CBFS_SUCCESS: | |
17 | return "Success"; | |
18 | case CBFS_NOT_INITIALIZED: | |
19 | return "CBFS not initialized"; | |
20 | case CBFS_BAD_HEADER: | |
21 | return "Bad CBFS header"; | |
22 | case CBFS_BAD_FILE: | |
23 | return "Bad CBFS file"; | |
24 | case CBFS_FILE_NOT_FOUND: | |
25 | return "File not found"; | |
26 | default: | |
27 | return "Unknown"; | |
28 | } | |
29 | } | |
30 | ||
31 | ||
32 | static const u32 good_magic = 0x4f524243; | |
33 | static const u8 good_file_magic[] = "LARCHIVE"; | |
34 | ||
35 | ||
36 | static int initialized; | |
37 | static struct cbfs_header cbfs_header; | |
38 | static struct cbfs_cachenode *file_cache; | |
39 | ||
40 | /* Do endian conversion on the CBFS header structure. */ | |
41 | static void swap_header(struct cbfs_header *dest, struct cbfs_header *src) | |
42 | { | |
43 | dest->magic = be32_to_cpu(src->magic); | |
44 | dest->version = be32_to_cpu(src->version); | |
45 | dest->rom_size = be32_to_cpu(src->rom_size); | |
46 | dest->boot_block_size = be32_to_cpu(src->boot_block_size); | |
47 | dest->align = be32_to_cpu(src->align); | |
48 | dest->offset = be32_to_cpu(src->offset); | |
49 | } | |
50 | ||
51 | /* Do endian conversion on a CBFS file header. */ | |
52 | static void swap_file_header(struct cbfs_fileheader *dest, | |
53 | const struct cbfs_fileheader *src) | |
54 | { | |
55 | memcpy(&dest->magic, &src->magic, sizeof(dest->magic)); | |
56 | dest->len = be32_to_cpu(src->len); | |
57 | dest->type = be32_to_cpu(src->type); | |
58 | dest->checksum = be32_to_cpu(src->checksum); | |
59 | dest->offset = be32_to_cpu(src->offset); | |
60 | } | |
61 | ||
62 | /* | |
63 | * Given a starting position in memory, scan forward, bounded by a size, and | |
64 | * find the next valid CBFS file. No memory is allocated by this function. The | |
65 | * caller is responsible for allocating space for the new file structure. | |
66 | * | |
67 | * @param start The location in memory to start from. | |
68 | * @param size The size of the memory region to search. | |
69 | * @param align The alignment boundaries to check on. | |
70 | * @param newNode A pointer to the file structure to load. | |
71 | * @param used A pointer to the count of of bytes scanned through, | |
72 | * including the file if one is found. | |
73 | * | |
74 | * @return 1 if a file is found, 0 if one isn't. | |
75 | */ | |
76 | static int file_cbfs_next_file(u8 *start, u32 size, u32 align, | |
77 | struct cbfs_cachenode *newNode, u32 *used) | |
78 | { | |
79 | struct cbfs_fileheader header; | |
80 | ||
81 | *used = 0; | |
82 | ||
83 | while (size >= align) { | |
84 | const struct cbfs_fileheader *fileHeader = | |
85 | (const struct cbfs_fileheader *)start; | |
86 | u32 name_len; | |
87 | u32 step; | |
88 | ||
89 | /* Check if there's a file here. */ | |
90 | if (memcmp(good_file_magic, &(fileHeader->magic), | |
91 | sizeof(fileHeader->magic))) { | |
92 | *used += align; | |
93 | size -= align; | |
94 | start += align; | |
95 | continue; | |
96 | } | |
97 | ||
98 | swap_file_header(&header, fileHeader); | |
99 | if (header.offset < sizeof(const struct cbfs_cachenode *) || | |
100 | header.offset > header.len) { | |
101 | file_cbfs_result = CBFS_BAD_FILE; | |
102 | return -1; | |
103 | } | |
104 | newNode->next = NULL; | |
105 | newNode->type = header.type; | |
106 | newNode->data = start + header.offset; | |
107 | newNode->data_length = header.len; | |
108 | name_len = header.offset - sizeof(struct cbfs_cachenode *); | |
109 | newNode->name = (char *)fileHeader + | |
110 | sizeof(struct cbfs_cachenode *); | |
111 | newNode->name_length = name_len; | |
112 | newNode->checksum = header.checksum; | |
113 | ||
114 | step = header.len; | |
115 | if (step % align) | |
116 | step = step + align - step % align; | |
117 | ||
118 | *used += step; | |
119 | return 1; | |
120 | } | |
121 | return 0; | |
122 | } | |
123 | ||
124 | /* Look through a CBFS instance and copy file metadata into regular memory. */ | |
125 | static void file_cbfs_fill_cache(u8 *start, u32 size, u32 align) | |
126 | { | |
127 | struct cbfs_cachenode *cache_node; | |
128 | struct cbfs_cachenode *newNode; | |
129 | struct cbfs_cachenode **cache_tail = &file_cache; | |
130 | ||
131 | /* Clear out old information. */ | |
132 | cache_node = file_cache; | |
133 | while (cache_node) { | |
134 | struct cbfs_cachenode *oldNode = cache_node; | |
135 | cache_node = cache_node->next; | |
136 | free(oldNode); | |
137 | } | |
138 | file_cache = NULL; | |
139 | ||
140 | while (size >= align) { | |
141 | int result; | |
142 | u32 used; | |
143 | ||
144 | newNode = (struct cbfs_cachenode *) | |
145 | malloc(sizeof(struct cbfs_cachenode)); | |
146 | result = file_cbfs_next_file(start, size, align, | |
147 | newNode, &used); | |
148 | ||
149 | if (result < 0) { | |
150 | free(newNode); | |
151 | return; | |
152 | } else if (result == 0) { | |
153 | free(newNode); | |
154 | break; | |
155 | } | |
156 | *cache_tail = newNode; | |
157 | cache_tail = &newNode->next; | |
158 | ||
159 | size -= used; | |
160 | start += used; | |
161 | } | |
162 | file_cbfs_result = CBFS_SUCCESS; | |
163 | } | |
164 | ||
165 | /* Get the CBFS header out of the ROM and do endian conversion. */ | |
166 | static int file_cbfs_load_header(uintptr_t end_of_rom, | |
167 | struct cbfs_header *header) | |
168 | { | |
169 | struct cbfs_header *header_in_rom; | |
170 | ||
171 | header_in_rom = (struct cbfs_header *)(uintptr_t) | |
172 | *(u32 *)(end_of_rom - 3); | |
173 | swap_header(header, header_in_rom); | |
174 | ||
175 | if (header->magic != good_magic || header->offset > | |
176 | header->rom_size - header->boot_block_size) { | |
177 | file_cbfs_result = CBFS_BAD_HEADER; | |
178 | return 1; | |
179 | } | |
180 | return 0; | |
181 | } | |
182 | ||
183 | void file_cbfs_init(uintptr_t end_of_rom) | |
184 | { | |
185 | u8 *start_of_rom; | |
186 | initialized = 0; | |
187 | ||
188 | if (file_cbfs_load_header(end_of_rom, &cbfs_header)) | |
189 | return; | |
190 | ||
191 | start_of_rom = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size); | |
192 | ||
193 | file_cbfs_fill_cache(start_of_rom + cbfs_header.offset, | |
194 | cbfs_header.rom_size, cbfs_header.align); | |
195 | if (file_cbfs_result == CBFS_SUCCESS) | |
196 | initialized = 1; | |
197 | } | |
198 | ||
199 | const struct cbfs_header *file_cbfs_get_header(void) | |
200 | { | |
201 | if (initialized) { | |
202 | file_cbfs_result = CBFS_SUCCESS; | |
203 | return &cbfs_header; | |
204 | } else { | |
205 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
206 | return NULL; | |
207 | } | |
208 | } | |
209 | ||
210 | const struct cbfs_cachenode *file_cbfs_get_first(void) | |
211 | { | |
212 | if (!initialized) { | |
213 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
214 | return NULL; | |
215 | } else { | |
216 | file_cbfs_result = CBFS_SUCCESS; | |
217 | return file_cache; | |
218 | } | |
219 | } | |
220 | ||
221 | void file_cbfs_get_next(const struct cbfs_cachenode **file) | |
222 | { | |
223 | if (!initialized) { | |
224 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
225 | file = NULL; | |
226 | return; | |
227 | } | |
228 | ||
229 | if (*file) | |
230 | *file = (*file)->next; | |
231 | file_cbfs_result = CBFS_SUCCESS; | |
232 | } | |
233 | ||
234 | const struct cbfs_cachenode *file_cbfs_find(const char *name) | |
235 | { | |
236 | struct cbfs_cachenode *cache_node = file_cache; | |
237 | ||
238 | if (!initialized) { | |
239 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
240 | return NULL; | |
241 | } | |
242 | ||
243 | while (cache_node) { | |
244 | if (!strcmp(name, cache_node->name)) | |
245 | break; | |
246 | cache_node = cache_node->next; | |
247 | } | |
248 | if (!cache_node) | |
249 | file_cbfs_result = CBFS_FILE_NOT_FOUND; | |
250 | else | |
251 | file_cbfs_result = CBFS_SUCCESS; | |
252 | ||
253 | return cache_node; | |
254 | } | |
255 | ||
256 | const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom, | |
257 | const char *name) | |
258 | { | |
259 | u8 *start; | |
260 | u32 size; | |
261 | u32 align; | |
262 | static struct cbfs_cachenode node; | |
263 | ||
264 | if (file_cbfs_load_header(end_of_rom, &cbfs_header)) | |
265 | return NULL; | |
266 | ||
267 | start = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size); | |
268 | size = cbfs_header.rom_size; | |
269 | align = cbfs_header.align; | |
270 | ||
271 | while (size >= align) { | |
272 | int result; | |
273 | u32 used; | |
274 | ||
275 | result = file_cbfs_next_file(start, size, align, &node, &used); | |
276 | ||
277 | if (result < 0) | |
278 | return NULL; | |
279 | else if (result == 0) | |
280 | break; | |
281 | ||
282 | if (!strcmp(name, node.name)) | |
283 | return &node; | |
284 | ||
285 | size -= used; | |
286 | start += used; | |
287 | } | |
288 | file_cbfs_result = CBFS_FILE_NOT_FOUND; | |
289 | return NULL; | |
290 | } | |
291 | ||
292 | const char *file_cbfs_name(const struct cbfs_cachenode *file) | |
293 | { | |
294 | file_cbfs_result = CBFS_SUCCESS; | |
295 | return file->name; | |
296 | } | |
297 | ||
298 | u32 file_cbfs_size(const struct cbfs_cachenode *file) | |
299 | { | |
300 | file_cbfs_result = CBFS_SUCCESS; | |
301 | return file->data_length; | |
302 | } | |
303 | ||
304 | u32 file_cbfs_type(const struct cbfs_cachenode *file) | |
305 | { | |
306 | file_cbfs_result = CBFS_SUCCESS; | |
307 | return file->type; | |
308 | } | |
309 | ||
310 | long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer, | |
311 | unsigned long maxsize) | |
312 | { | |
313 | u32 size; | |
314 | ||
315 | size = file->data_length; | |
316 | if (maxsize && size > maxsize) | |
317 | size = maxsize; | |
318 | ||
319 | memcpy(buffer, file->data, size); | |
320 | ||
321 | file_cbfs_result = CBFS_SUCCESS; | |
322 | return size; | |
323 | } |