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1 | /* |
2 | * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. | |
3 | * | |
4 | * See file CREDITS for list of people who contributed to this | |
5 | * project. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License as | |
9 | * published by the Free Software Foundation; either version 2 of | |
10 | * the License, or (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
20 | * MA 02111-1307 USA | |
21 | */ | |
22 | ||
23 | #include <cbfs.h> | |
24 | #include <malloc.h> | |
25 | #include <asm/byteorder.h> | |
26 | ||
27 | enum cbfs_result file_cbfs_result; | |
28 | ||
29 | const char *file_cbfs_error(void) | |
30 | { | |
31 | switch (file_cbfs_result) { | |
32 | case CBFS_SUCCESS: | |
33 | return "Success"; | |
34 | case CBFS_NOT_INITIALIZED: | |
35 | return "CBFS not initialized"; | |
36 | case CBFS_BAD_HEADER: | |
37 | return "Bad CBFS header"; | |
38 | case CBFS_BAD_FILE: | |
39 | return "Bad CBFS file"; | |
40 | case CBFS_FILE_NOT_FOUND: | |
41 | return "File not found"; | |
42 | default: | |
43 | return "Unknown"; | |
44 | } | |
45 | } | |
46 | ||
47 | ||
48 | static const u32 good_magic = 0x4f524243; | |
49 | static const u8 good_file_magic[] = "LARCHIVE"; | |
50 | ||
51 | ||
52 | static int initialized; | |
53 | static struct cbfs_header cbfs_header; | |
54 | static struct cbfs_cachenode *file_cache; | |
55 | ||
56 | /* Do endian conversion on the CBFS header structure. */ | |
57 | static void swap_header(struct cbfs_header *dest, struct cbfs_header *src) | |
58 | { | |
59 | dest->magic = be32_to_cpu(src->magic); | |
60 | dest->version = be32_to_cpu(src->version); | |
61 | dest->rom_size = be32_to_cpu(src->rom_size); | |
62 | dest->boot_block_size = be32_to_cpu(src->boot_block_size); | |
63 | dest->align = be32_to_cpu(src->align); | |
64 | dest->offset = be32_to_cpu(src->offset); | |
65 | } | |
66 | ||
67 | /* Do endian conversion on a CBFS file header. */ | |
68 | static void swap_file_header(struct cbfs_fileheader *dest, | |
69 | const struct cbfs_fileheader *src) | |
70 | { | |
71 | memcpy(&dest->magic, &src->magic, sizeof(dest->magic)); | |
72 | dest->len = be32_to_cpu(src->len); | |
73 | dest->type = be32_to_cpu(src->type); | |
74 | dest->checksum = be32_to_cpu(src->checksum); | |
75 | dest->offset = be32_to_cpu(src->offset); | |
76 | } | |
77 | ||
78 | /* | |
79 | * Given a starting position in memory, scan forward, bounded by a size, and | |
80 | * find the next valid CBFS file. No memory is allocated by this function. The | |
81 | * caller is responsible for allocating space for the new file structure. | |
82 | * | |
83 | * @param start The location in memory to start from. | |
84 | * @param size The size of the memory region to search. | |
85 | * @param align The alignment boundaries to check on. | |
86 | * @param newNode A pointer to the file structure to load. | |
87 | * @param used A pointer to the count of of bytes scanned through, | |
88 | * including the file if one is found. | |
89 | * | |
90 | * @return 1 if a file is found, 0 if one isn't. | |
91 | */ | |
92 | static int file_cbfs_next_file(u8 *start, u32 size, u32 align, | |
93 | struct cbfs_cachenode *newNode, u32 *used) | |
94 | { | |
95 | struct cbfs_fileheader header; | |
96 | ||
97 | *used = 0; | |
98 | ||
99 | while (size >= align) { | |
100 | const struct cbfs_fileheader *fileHeader = | |
101 | (const struct cbfs_fileheader *)start; | |
102 | u32 name_len; | |
103 | u32 step; | |
104 | ||
105 | /* Check if there's a file here. */ | |
106 | if (memcmp(good_file_magic, &(fileHeader->magic), | |
107 | sizeof(fileHeader->magic))) { | |
108 | *used += align; | |
109 | size -= align; | |
110 | start += align; | |
111 | continue; | |
112 | } | |
113 | ||
114 | swap_file_header(&header, fileHeader); | |
115 | if (header.offset < sizeof(const struct cbfs_cachenode *) || | |
116 | header.offset > header.len) { | |
117 | file_cbfs_result = CBFS_BAD_FILE; | |
118 | return -1; | |
119 | } | |
120 | newNode->next = NULL; | |
121 | newNode->type = header.type; | |
122 | newNode->data = start + header.offset; | |
123 | newNode->data_length = header.len; | |
124 | name_len = header.offset - sizeof(struct cbfs_cachenode *); | |
125 | newNode->name = (char *)fileHeader + | |
126 | sizeof(struct cbfs_cachenode *); | |
127 | newNode->name_length = name_len; | |
128 | newNode->checksum = header.checksum; | |
129 | ||
130 | step = header.len; | |
131 | if (step % align) | |
132 | step = step + align - step % align; | |
133 | ||
134 | *used += step; | |
135 | return 1; | |
136 | } | |
137 | return 0; | |
138 | } | |
139 | ||
140 | /* Look through a CBFS instance and copy file metadata into regular memory. */ | |
141 | static void file_cbfs_fill_cache(u8 *start, u32 size, u32 align) | |
142 | { | |
143 | struct cbfs_cachenode *cache_node; | |
144 | struct cbfs_cachenode *newNode; | |
145 | struct cbfs_cachenode **cache_tail = &file_cache; | |
146 | ||
147 | /* Clear out old information. */ | |
148 | cache_node = file_cache; | |
149 | while (cache_node) { | |
150 | struct cbfs_cachenode *oldNode = cache_node; | |
151 | cache_node = cache_node->next; | |
152 | free(oldNode); | |
153 | } | |
154 | file_cache = NULL; | |
155 | ||
156 | while (size >= align) { | |
157 | int result; | |
158 | u32 used; | |
159 | ||
160 | newNode = (struct cbfs_cachenode *) | |
161 | malloc(sizeof(struct cbfs_cachenode)); | |
162 | result = file_cbfs_next_file(start, size, align, | |
163 | newNode, &used); | |
164 | ||
165 | if (result < 0) { | |
166 | free(newNode); | |
167 | return; | |
168 | } else if (result == 0) { | |
169 | free(newNode); | |
170 | break; | |
171 | } | |
172 | *cache_tail = newNode; | |
173 | cache_tail = &newNode->next; | |
174 | ||
175 | size -= used; | |
176 | start += used; | |
177 | } | |
178 | file_cbfs_result = CBFS_SUCCESS; | |
179 | } | |
180 | ||
181 | /* Get the CBFS header out of the ROM and do endian conversion. */ | |
182 | static int file_cbfs_load_header(uintptr_t end_of_rom, | |
183 | struct cbfs_header *header) | |
184 | { | |
185 | struct cbfs_header *header_in_rom; | |
186 | ||
187 | header_in_rom = (struct cbfs_header *)(uintptr_t) | |
188 | *(u32 *)(end_of_rom - 3); | |
189 | swap_header(header, header_in_rom); | |
190 | ||
191 | if (header->magic != good_magic || header->offset > | |
192 | header->rom_size - header->boot_block_size) { | |
193 | file_cbfs_result = CBFS_BAD_HEADER; | |
194 | return 1; | |
195 | } | |
196 | return 0; | |
197 | } | |
198 | ||
199 | void file_cbfs_init(uintptr_t end_of_rom) | |
200 | { | |
201 | u8 *start_of_rom; | |
202 | initialized = 0; | |
203 | ||
204 | if (file_cbfs_load_header(end_of_rom, &cbfs_header)) | |
205 | return; | |
206 | ||
207 | start_of_rom = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size); | |
208 | ||
209 | file_cbfs_fill_cache(start_of_rom + cbfs_header.offset, | |
210 | cbfs_header.rom_size, cbfs_header.align); | |
211 | if (file_cbfs_result == CBFS_SUCCESS) | |
212 | initialized = 1; | |
213 | } | |
214 | ||
215 | const struct cbfs_header *file_cbfs_get_header(void) | |
216 | { | |
217 | if (initialized) { | |
218 | file_cbfs_result = CBFS_SUCCESS; | |
219 | return &cbfs_header; | |
220 | } else { | |
221 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
222 | return NULL; | |
223 | } | |
224 | } | |
225 | ||
226 | const struct cbfs_cachenode *file_cbfs_get_first(void) | |
227 | { | |
228 | if (!initialized) { | |
229 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
230 | return NULL; | |
231 | } else { | |
232 | file_cbfs_result = CBFS_SUCCESS; | |
233 | return file_cache; | |
234 | } | |
235 | } | |
236 | ||
237 | void file_cbfs_get_next(const struct cbfs_cachenode **file) | |
238 | { | |
239 | if (!initialized) { | |
240 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
241 | file = NULL; | |
242 | return; | |
243 | } | |
244 | ||
245 | if (*file) | |
246 | *file = (*file)->next; | |
247 | file_cbfs_result = CBFS_SUCCESS; | |
248 | } | |
249 | ||
250 | const struct cbfs_cachenode *file_cbfs_find(const char *name) | |
251 | { | |
252 | struct cbfs_cachenode *cache_node = file_cache; | |
253 | ||
254 | if (!initialized) { | |
255 | file_cbfs_result = CBFS_NOT_INITIALIZED; | |
256 | return NULL; | |
257 | } | |
258 | ||
259 | while (cache_node) { | |
260 | if (!strcmp(name, cache_node->name)) | |
261 | break; | |
262 | cache_node = cache_node->next; | |
263 | } | |
264 | if (!cache_node) | |
265 | file_cbfs_result = CBFS_FILE_NOT_FOUND; | |
266 | else | |
267 | file_cbfs_result = CBFS_SUCCESS; | |
268 | ||
269 | return cache_node; | |
270 | } | |
271 | ||
272 | const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom, | |
273 | const char *name) | |
274 | { | |
275 | u8 *start; | |
276 | u32 size; | |
277 | u32 align; | |
278 | static struct cbfs_cachenode node; | |
279 | ||
280 | if (file_cbfs_load_header(end_of_rom, &cbfs_header)) | |
281 | return NULL; | |
282 | ||
283 | start = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size); | |
284 | size = cbfs_header.rom_size; | |
285 | align = cbfs_header.align; | |
286 | ||
287 | while (size >= align) { | |
288 | int result; | |
289 | u32 used; | |
290 | ||
291 | result = file_cbfs_next_file(start, size, align, &node, &used); | |
292 | ||
293 | if (result < 0) | |
294 | return NULL; | |
295 | else if (result == 0) | |
296 | break; | |
297 | ||
298 | if (!strcmp(name, node.name)) | |
299 | return &node; | |
300 | ||
301 | size -= used; | |
302 | start += used; | |
303 | } | |
304 | file_cbfs_result = CBFS_FILE_NOT_FOUND; | |
305 | return NULL; | |
306 | } | |
307 | ||
308 | const char *file_cbfs_name(const struct cbfs_cachenode *file) | |
309 | { | |
310 | file_cbfs_result = CBFS_SUCCESS; | |
311 | return file->name; | |
312 | } | |
313 | ||
314 | u32 file_cbfs_size(const struct cbfs_cachenode *file) | |
315 | { | |
316 | file_cbfs_result = CBFS_SUCCESS; | |
317 | return file->data_length; | |
318 | } | |
319 | ||
320 | u32 file_cbfs_type(const struct cbfs_cachenode *file) | |
321 | { | |
322 | file_cbfs_result = CBFS_SUCCESS; | |
323 | return file->type; | |
324 | } | |
325 | ||
326 | long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer, | |
327 | unsigned long maxsize) | |
328 | { | |
329 | u32 size; | |
330 | ||
331 | size = file->data_length; | |
332 | if (maxsize && size > maxsize) | |
333 | size = maxsize; | |
334 | ||
335 | memcpy(buffer, file->data, size); | |
336 | ||
337 | file_cbfs_result = CBFS_SUCCESS; | |
338 | return size; | |
339 | } |