1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
9 #include <asm/byteorder.h>
11 enum cbfs_result file_cbfs_result;
13 const char *file_cbfs_error(void)
15 switch (file_cbfs_result) {
18 case CBFS_NOT_INITIALIZED:
19 return "CBFS not initialized";
21 return "Bad CBFS header";
23 return "Bad CBFS file";
24 case CBFS_FILE_NOT_FOUND:
25 return "File not found";
32 static const u32 good_magic = 0x4f524243;
33 static const u8 good_file_magic[] = "LARCHIVE";
36 static int initialized;
37 static struct cbfs_header cbfs_header;
38 static struct cbfs_cachenode *file_cache;
40 /* Do endian conversion on the CBFS header structure. */
41 static void swap_header(struct cbfs_header *dest, struct cbfs_header *src)
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);
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)
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);
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.
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.
74 * @return 1 if a file is found, 0 if one isn't.
76 static int file_cbfs_next_file(u8 *start, u32 size, u32 align,
77 struct cbfs_cachenode *newNode, u32 *used)
79 struct cbfs_fileheader header;
83 while (size >= align) {
84 const struct cbfs_fileheader *fileHeader =
85 (const struct cbfs_fileheader *)start;
89 /* Check if there's a file here. */
90 if (memcmp(good_file_magic, &(fileHeader->magic),
91 sizeof(fileHeader->magic))) {
98 swap_file_header(&header, fileHeader);
99 if (header.offset < sizeof(struct cbfs_fileheader)) {
100 file_cbfs_result = CBFS_BAD_FILE;
103 newNode->next = NULL;
104 newNode->type = header.type;
105 newNode->data = start + header.offset;
106 newNode->data_length = header.len;
107 name_len = header.offset - sizeof(struct cbfs_fileheader);
108 newNode->name = (char *)fileHeader +
109 sizeof(struct cbfs_fileheader);
110 newNode->name_length = name_len;
111 newNode->checksum = header.checksum;
115 step = step + align - step % align;
123 /* Look through a CBFS instance and copy file metadata into regular memory. */
124 static void file_cbfs_fill_cache(u8 *start, u32 size, u32 align)
126 struct cbfs_cachenode *cache_node;
127 struct cbfs_cachenode *newNode;
128 struct cbfs_cachenode **cache_tail = &file_cache;
130 /* Clear out old information. */
131 cache_node = file_cache;
133 struct cbfs_cachenode *oldNode = cache_node;
134 cache_node = cache_node->next;
139 while (size >= align) {
143 newNode = (struct cbfs_cachenode *)
144 malloc(sizeof(struct cbfs_cachenode));
145 result = file_cbfs_next_file(start, size, align,
151 } else if (result == 0) {
155 *cache_tail = newNode;
156 cache_tail = &newNode->next;
161 file_cbfs_result = CBFS_SUCCESS;
164 /* Get the CBFS header out of the ROM and do endian conversion. */
165 static int file_cbfs_load_header(uintptr_t end_of_rom,
166 struct cbfs_header *header)
168 struct cbfs_header *header_in_rom;
169 int32_t offset = *(u32 *)(end_of_rom - 3);
171 header_in_rom = (struct cbfs_header *)(end_of_rom + offset + 1);
172 swap_header(header, header_in_rom);
174 if (header->magic != good_magic || header->offset >
175 header->rom_size - header->boot_block_size) {
176 file_cbfs_result = CBFS_BAD_HEADER;
182 void file_cbfs_init(uintptr_t end_of_rom)
187 if (file_cbfs_load_header(end_of_rom, &cbfs_header))
190 start_of_rom = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
192 file_cbfs_fill_cache(start_of_rom + cbfs_header.offset,
193 cbfs_header.rom_size, cbfs_header.align);
194 if (file_cbfs_result == CBFS_SUCCESS)
198 const struct cbfs_header *file_cbfs_get_header(void)
201 file_cbfs_result = CBFS_SUCCESS;
204 file_cbfs_result = CBFS_NOT_INITIALIZED;
209 const struct cbfs_cachenode *file_cbfs_get_first(void)
212 file_cbfs_result = CBFS_NOT_INITIALIZED;
215 file_cbfs_result = CBFS_SUCCESS;
220 void file_cbfs_get_next(const struct cbfs_cachenode **file)
223 file_cbfs_result = CBFS_NOT_INITIALIZED;
229 *file = (*file)->next;
230 file_cbfs_result = CBFS_SUCCESS;
233 const struct cbfs_cachenode *file_cbfs_find(const char *name)
235 struct cbfs_cachenode *cache_node = file_cache;
238 file_cbfs_result = CBFS_NOT_INITIALIZED;
243 if (!strcmp(name, cache_node->name))
245 cache_node = cache_node->next;
248 file_cbfs_result = CBFS_FILE_NOT_FOUND;
250 file_cbfs_result = CBFS_SUCCESS;
255 const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom,
261 static struct cbfs_cachenode node;
263 if (file_cbfs_load_header(end_of_rom, &cbfs_header))
266 start = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
267 size = cbfs_header.rom_size;
268 align = cbfs_header.align;
270 while (size >= align) {
274 result = file_cbfs_next_file(start, size, align, &node, &used);
278 else if (result == 0)
281 if (!strcmp(name, node.name))
287 file_cbfs_result = CBFS_FILE_NOT_FOUND;
291 const char *file_cbfs_name(const struct cbfs_cachenode *file)
293 file_cbfs_result = CBFS_SUCCESS;
297 u32 file_cbfs_size(const struct cbfs_cachenode *file)
299 file_cbfs_result = CBFS_SUCCESS;
300 return file->data_length;
303 u32 file_cbfs_type(const struct cbfs_cachenode *file)
305 file_cbfs_result = CBFS_SUCCESS;
309 long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
310 unsigned long maxsize)
314 size = file->data_length;
315 if (maxsize && size > maxsize)
318 memcpy(buffer, file->data, size);
320 file_cbfs_result = CBFS_SUCCESS;