Gabe Black | 84cd932 | 2012-10-12 14:26:11 +0000 | [diff] [blame] | 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 | } |