1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
9 #include <asm/byteorder.h>
11 static const u32 good_magic = 0x4f524243;
12 static const u8 good_file_magic[] = "LARCHIVE";
16 struct cbfs_header header;
17 struct cbfs_cachenode *file_cache;
18 enum cbfs_result result;
21 static struct cbfs_priv cbfs_s;
23 const char *file_cbfs_error(void)
25 switch (cbfs_s.result) {
28 case CBFS_NOT_INITIALIZED:
29 return "CBFS not initialized";
31 return "Bad CBFS header";
33 return "Bad CBFS file";
34 case CBFS_FILE_NOT_FOUND:
35 return "File not found";
41 enum cbfs_result cbfs_get_result(void)
46 /* Do endian conversion on the CBFS header structure. */
47 static void swap_header(struct cbfs_header *dest, struct cbfs_header *src)
49 dest->magic = be32_to_cpu(src->magic);
50 dest->version = be32_to_cpu(src->version);
51 dest->rom_size = be32_to_cpu(src->rom_size);
52 dest->boot_block_size = be32_to_cpu(src->boot_block_size);
53 dest->align = be32_to_cpu(src->align);
54 dest->offset = be32_to_cpu(src->offset);
57 /* Do endian conversion on a CBFS file header. */
58 static void swap_file_header(struct cbfs_fileheader *dest,
59 const struct cbfs_fileheader *src)
61 memcpy(&dest->magic, &src->magic, sizeof(dest->magic));
62 dest->len = be32_to_cpu(src->len);
63 dest->type = be32_to_cpu(src->type);
64 dest->attributes_offset = be32_to_cpu(src->attributes_offset);
65 dest->offset = be32_to_cpu(src->offset);
69 * Given a starting position in memory, scan forward, bounded by a size, and
70 * find the next valid CBFS file. No memory is allocated by this function. The
71 * caller is responsible for allocating space for the new file structure.
73 * @param start The location in memory to start from.
74 * @param size The size of the memory region to search.
75 * @param align The alignment boundaries to check on.
76 * @param newNode A pointer to the file structure to load.
77 * @param used A pointer to the count of of bytes scanned through,
78 * including the file if one is found.
80 * @return 1 if a file is found, 0 if one isn't.
82 static int file_cbfs_next_file(struct cbfs_priv *priv, u8 *start, u32 size,
83 u32 align, struct cbfs_cachenode *newNode,
86 struct cbfs_fileheader header;
90 while (size >= align) {
91 const struct cbfs_fileheader *fileHeader =
92 (const struct cbfs_fileheader *)start;
96 /* Check if there's a file here. */
97 if (memcmp(good_file_magic, &(fileHeader->magic),
98 sizeof(fileHeader->magic))) {
105 swap_file_header(&header, fileHeader);
106 if (header.offset < sizeof(struct cbfs_fileheader)) {
107 priv->result = CBFS_BAD_FILE;
110 newNode->next = NULL;
111 newNode->type = header.type;
112 newNode->data = start + header.offset;
113 newNode->data_length = header.len;
114 name_len = header.offset - sizeof(struct cbfs_fileheader);
115 newNode->name = (char *)fileHeader +
116 sizeof(struct cbfs_fileheader);
117 newNode->name_length = name_len;
118 newNode->attributes_offset = header.attributes_offset;
122 step = step + align - step % align;
130 /* Look through a CBFS instance and copy file metadata into regular memory. */
131 static void file_cbfs_fill_cache(struct cbfs_priv *priv, u8 *start, u32 size,
134 struct cbfs_cachenode *cache_node;
135 struct cbfs_cachenode *newNode;
136 struct cbfs_cachenode **cache_tail = &priv->file_cache;
138 /* Clear out old information. */
139 cache_node = priv->file_cache;
141 struct cbfs_cachenode *oldNode = cache_node;
142 cache_node = cache_node->next;
145 priv->file_cache = NULL;
147 while (size >= align) {
151 newNode = (struct cbfs_cachenode *)
152 malloc(sizeof(struct cbfs_cachenode));
153 result = file_cbfs_next_file(priv, start, size, align, newNode,
159 } else if (result == 0) {
163 *cache_tail = newNode;
164 cache_tail = &newNode->next;
169 priv->result = CBFS_SUCCESS;
172 /* Get the CBFS header out of the ROM and do endian conversion. */
173 static int file_cbfs_load_header(uintptr_t end_of_rom,
174 struct cbfs_header *header)
176 struct cbfs_header *header_in_rom;
177 int32_t offset = *(u32 *)(end_of_rom - 3);
179 header_in_rom = (struct cbfs_header *)(end_of_rom + offset + 1);
180 swap_header(header, header_in_rom);
182 if (header->magic != good_magic || header->offset >
183 header->rom_size - header->boot_block_size) {
184 cbfs_s.result = CBFS_BAD_HEADER;
190 static int cbfs_load_header_ptr(struct cbfs_priv *priv, ulong base,
191 struct cbfs_header *header)
193 struct cbfs_header *header_in_rom;
195 header_in_rom = (struct cbfs_header *)base;
196 swap_header(header, header_in_rom);
198 if (header->magic != good_magic || header->offset >
199 header->rom_size - header->boot_block_size) {
200 priv->result = CBFS_BAD_HEADER;
207 static void cbfs_init(struct cbfs_priv *priv, uintptr_t end_of_rom)
211 priv->initialized = 0;
213 if (file_cbfs_load_header(end_of_rom, &priv->header))
216 start_of_rom = (u8 *)(end_of_rom + 1 - priv->header.rom_size);
218 file_cbfs_fill_cache(priv, start_of_rom, priv->header.rom_size,
220 if (priv->result == CBFS_SUCCESS)
221 priv->initialized = 1;
224 void file_cbfs_init(uintptr_t end_of_rom)
226 cbfs_init(&cbfs_s, end_of_rom);
229 int cbfs_init_mem(ulong base, ulong size, struct cbfs_priv **privp)
231 struct cbfs_priv priv_s, *priv = &priv_s;
235 * Use a local variable to start with until we know that the CBFS is
236 * valid. Assume that a master header appears at the start, at offset
239 ret = cbfs_load_header_ptr(priv, base + 0x38, &priv->header);
243 file_cbfs_fill_cache(priv, (u8 *)base, priv->header.rom_size,
245 if (priv->result != CBFS_SUCCESS)
248 priv->initialized = 1;
249 priv = malloc(sizeof(priv_s));
252 memcpy(priv, &priv_s, sizeof(priv_s));
258 const struct cbfs_header *file_cbfs_get_header(void)
260 struct cbfs_priv *priv = &cbfs_s;
262 if (priv->initialized) {
263 priv->result = CBFS_SUCCESS;
264 return &priv->header;
266 priv->result = CBFS_NOT_INITIALIZED;
271 const struct cbfs_cachenode *file_cbfs_get_first(void)
273 struct cbfs_priv *priv = &cbfs_s;
275 if (!priv->initialized) {
276 priv->result = CBFS_NOT_INITIALIZED;
279 priv->result = CBFS_SUCCESS;
280 return priv->file_cache;
284 void file_cbfs_get_next(const struct cbfs_cachenode **file)
286 struct cbfs_priv *priv = &cbfs_s;
288 if (!priv->initialized) {
289 priv->result = CBFS_NOT_INITIALIZED;
295 *file = (*file)->next;
296 priv->result = CBFS_SUCCESS;
299 const struct cbfs_cachenode *cbfs_find_file(struct cbfs_priv *priv,
302 struct cbfs_cachenode *cache_node = priv->file_cache;
304 if (!priv->initialized) {
305 priv->result = CBFS_NOT_INITIALIZED;
310 if (!strcmp(name, cache_node->name))
312 cache_node = cache_node->next;
315 priv->result = CBFS_FILE_NOT_FOUND;
317 priv->result = CBFS_SUCCESS;
322 const struct cbfs_cachenode *file_cbfs_find(const char *name)
324 return cbfs_find_file(&cbfs_s, name);
327 const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom,
330 struct cbfs_priv *priv = &cbfs_s;
334 static struct cbfs_cachenode node;
336 if (file_cbfs_load_header(end_of_rom, &priv->header))
339 start = (u8 *)(end_of_rom + 1 - priv->header.rom_size);
340 size = priv->header.rom_size;
341 align = priv->header.align;
343 while (size >= align) {
347 result = file_cbfs_next_file(priv, start, size, align, &node,
352 else if (result == 0)
355 if (!strcmp(name, node.name))
361 cbfs_s.result = CBFS_FILE_NOT_FOUND;
365 const char *file_cbfs_name(const struct cbfs_cachenode *file)
367 cbfs_s.result = CBFS_SUCCESS;
372 u32 file_cbfs_size(const struct cbfs_cachenode *file)
374 cbfs_s.result = CBFS_SUCCESS;
376 return file->data_length;
379 u32 file_cbfs_type(const struct cbfs_cachenode *file)
381 cbfs_s.result = CBFS_SUCCESS;
386 long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
387 unsigned long maxsize)
391 size = file->data_length;
392 if (maxsize && size > maxsize)
395 memcpy(buffer, file->data, size);
396 cbfs_s.result = CBFS_SUCCESS;