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 void cbfs_init(struct cbfs_priv *priv, uintptr_t end_of_rom)
194 priv->initialized = 0;
196 if (file_cbfs_load_header(end_of_rom, &priv->header))
199 start_of_rom = (u8 *)(end_of_rom + 1 - priv->header.rom_size);
201 file_cbfs_fill_cache(priv, start_of_rom, priv->header.rom_size,
203 if (priv->result == CBFS_SUCCESS)
204 priv->initialized = 1;
207 void file_cbfs_init(uintptr_t end_of_rom)
209 cbfs_init(&cbfs_s, end_of_rom);
212 const struct cbfs_header *file_cbfs_get_header(void)
214 struct cbfs_priv *priv = &cbfs_s;
216 if (priv->initialized) {
217 priv->result = CBFS_SUCCESS;
218 return &priv->header;
220 priv->result = CBFS_NOT_INITIALIZED;
225 const struct cbfs_cachenode *file_cbfs_get_first(void)
227 struct cbfs_priv *priv = &cbfs_s;
229 if (!priv->initialized) {
230 priv->result = CBFS_NOT_INITIALIZED;
233 priv->result = CBFS_SUCCESS;
234 return priv->file_cache;
238 void file_cbfs_get_next(const struct cbfs_cachenode **file)
240 struct cbfs_priv *priv = &cbfs_s;
242 if (!priv->initialized) {
243 priv->result = CBFS_NOT_INITIALIZED;
249 *file = (*file)->next;
250 priv->result = CBFS_SUCCESS;
253 const struct cbfs_cachenode *cbfs_find_file(struct cbfs_priv *priv,
256 struct cbfs_cachenode *cache_node = priv->file_cache;
258 if (!priv->initialized) {
259 priv->result = CBFS_NOT_INITIALIZED;
264 if (!strcmp(name, cache_node->name))
266 cache_node = cache_node->next;
269 priv->result = CBFS_FILE_NOT_FOUND;
271 priv->result = CBFS_SUCCESS;
276 const struct cbfs_cachenode *file_cbfs_find(const char *name)
278 return cbfs_find_file(&cbfs_s, name);
281 const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom,
284 struct cbfs_priv *priv = &cbfs_s;
288 static struct cbfs_cachenode node;
290 if (file_cbfs_load_header(end_of_rom, &priv->header))
293 start = (u8 *)(end_of_rom + 1 - priv->header.rom_size);
294 size = priv->header.rom_size;
295 align = priv->header.align;
297 while (size >= align) {
301 result = file_cbfs_next_file(priv, start, size, align, &node,
306 else if (result == 0)
309 if (!strcmp(name, node.name))
315 cbfs_s.result = CBFS_FILE_NOT_FOUND;
319 const char *file_cbfs_name(const struct cbfs_cachenode *file)
321 cbfs_s.result = CBFS_SUCCESS;
326 u32 file_cbfs_size(const struct cbfs_cachenode *file)
328 cbfs_s.result = CBFS_SUCCESS;
330 return file->data_length;
333 u32 file_cbfs_type(const struct cbfs_cachenode *file)
335 cbfs_s.result = CBFS_SUCCESS;
340 long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
341 unsigned long maxsize)
345 size = file->data_length;
346 if (maxsize && size > maxsize)
349 memcpy(buffer, file->data, size);
350 cbfs_s.result = CBFS_SUCCESS;