summaryrefslogtreecommitdiff
path: root/fs/cbfs/cbfs.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/cbfs/cbfs.c')
-rw-r--r--fs/cbfs/cbfs.c339
1 files changed, 339 insertions, 0 deletions
diff --git a/fs/cbfs/cbfs.c b/fs/cbfs/cbfs.c
new file mode 100644
index 0000000..cae6d56
--- /dev/null
+++ b/fs/cbfs/cbfs.c
@@ -0,0 +1,339 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <cbfs.h>
+#include <malloc.h>
+#include <asm/byteorder.h>
+
+enum cbfs_result file_cbfs_result;
+
+const char *file_cbfs_error(void)
+{
+ switch (file_cbfs_result) {
+ case CBFS_SUCCESS:
+ return "Success";
+ case CBFS_NOT_INITIALIZED:
+ return "CBFS not initialized";
+ case CBFS_BAD_HEADER:
+ return "Bad CBFS header";
+ case CBFS_BAD_FILE:
+ return "Bad CBFS file";
+ case CBFS_FILE_NOT_FOUND:
+ return "File not found";
+ default:
+ return "Unknown";
+ }
+}
+
+
+static const u32 good_magic = 0x4f524243;
+static const u8 good_file_magic[] = "LARCHIVE";
+
+
+static int initialized;
+static struct cbfs_header cbfs_header;
+static struct cbfs_cachenode *file_cache;
+
+/* Do endian conversion on the CBFS header structure. */
+static void swap_header(struct cbfs_header *dest, struct cbfs_header *src)
+{
+ dest->magic = be32_to_cpu(src->magic);
+ dest->version = be32_to_cpu(src->version);
+ dest->rom_size = be32_to_cpu(src->rom_size);
+ dest->boot_block_size = be32_to_cpu(src->boot_block_size);
+ dest->align = be32_to_cpu(src->align);
+ dest->offset = be32_to_cpu(src->offset);
+}
+
+/* Do endian conversion on a CBFS file header. */
+static void swap_file_header(struct cbfs_fileheader *dest,
+ const struct cbfs_fileheader *src)
+{
+ memcpy(&dest->magic, &src->magic, sizeof(dest->magic));
+ dest->len = be32_to_cpu(src->len);
+ dest->type = be32_to_cpu(src->type);
+ dest->checksum = be32_to_cpu(src->checksum);
+ dest->offset = be32_to_cpu(src->offset);
+}
+
+/*
+ * Given a starting position in memory, scan forward, bounded by a size, and
+ * find the next valid CBFS file. No memory is allocated by this function. The
+ * caller is responsible for allocating space for the new file structure.
+ *
+ * @param start The location in memory to start from.
+ * @param size The size of the memory region to search.
+ * @param align The alignment boundaries to check on.
+ * @param newNode A pointer to the file structure to load.
+ * @param used A pointer to the count of of bytes scanned through,
+ * including the file if one is found.
+ *
+ * @return 1 if a file is found, 0 if one isn't.
+ */
+static int file_cbfs_next_file(u8 *start, u32 size, u32 align,
+ struct cbfs_cachenode *newNode, u32 *used)
+{
+ struct cbfs_fileheader header;
+
+ *used = 0;
+
+ while (size >= align) {
+ const struct cbfs_fileheader *fileHeader =
+ (const struct cbfs_fileheader *)start;
+ u32 name_len;
+ u32 step;
+
+ /* Check if there's a file here. */
+ if (memcmp(good_file_magic, &(fileHeader->magic),
+ sizeof(fileHeader->magic))) {
+ *used += align;
+ size -= align;
+ start += align;
+ continue;
+ }
+
+ swap_file_header(&header, fileHeader);
+ if (header.offset < sizeof(const struct cbfs_cachenode *) ||
+ header.offset > header.len) {
+ file_cbfs_result = CBFS_BAD_FILE;
+ return -1;
+ }
+ newNode->next = NULL;
+ newNode->type = header.type;
+ newNode->data = start + header.offset;
+ newNode->data_length = header.len;
+ name_len = header.offset - sizeof(struct cbfs_cachenode *);
+ newNode->name = (char *)fileHeader +
+ sizeof(struct cbfs_cachenode *);
+ newNode->name_length = name_len;
+ newNode->checksum = header.checksum;
+
+ step = header.len;
+ if (step % align)
+ step = step + align - step % align;
+
+ *used += step;
+ return 1;
+ }
+ return 0;
+}
+
+/* Look through a CBFS instance and copy file metadata into regular memory. */
+static void file_cbfs_fill_cache(u8 *start, u32 size, u32 align)
+{
+ struct cbfs_cachenode *cache_node;
+ struct cbfs_cachenode *newNode;
+ struct cbfs_cachenode **cache_tail = &file_cache;
+
+ /* Clear out old information. */
+ cache_node = file_cache;
+ while (cache_node) {
+ struct cbfs_cachenode *oldNode = cache_node;
+ cache_node = cache_node->next;
+ free(oldNode);
+ }
+ file_cache = NULL;
+
+ while (size >= align) {
+ int result;
+ u32 used;
+
+ newNode = (struct cbfs_cachenode *)
+ malloc(sizeof(struct cbfs_cachenode));
+ result = file_cbfs_next_file(start, size, align,
+ newNode, &used);
+
+ if (result < 0) {
+ free(newNode);
+ return;
+ } else if (result == 0) {
+ free(newNode);
+ break;
+ }
+ *cache_tail = newNode;
+ cache_tail = &newNode->next;
+
+ size -= used;
+ start += used;
+ }
+ file_cbfs_result = CBFS_SUCCESS;
+}
+
+/* Get the CBFS header out of the ROM and do endian conversion. */
+static int file_cbfs_load_header(uintptr_t end_of_rom,
+ struct cbfs_header *header)
+{
+ struct cbfs_header *header_in_rom;
+
+ header_in_rom = (struct cbfs_header *)(uintptr_t)
+ *(u32 *)(end_of_rom - 3);
+ swap_header(header, header_in_rom);
+
+ if (header->magic != good_magic || header->offset >
+ header->rom_size - header->boot_block_size) {
+ file_cbfs_result = CBFS_BAD_HEADER;
+ return 1;
+ }
+ return 0;
+}
+
+void file_cbfs_init(uintptr_t end_of_rom)
+{
+ u8 *start_of_rom;
+ initialized = 0;
+
+ if (file_cbfs_load_header(end_of_rom, &cbfs_header))
+ return;
+
+ start_of_rom = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
+
+ file_cbfs_fill_cache(start_of_rom + cbfs_header.offset,
+ cbfs_header.rom_size, cbfs_header.align);
+ if (file_cbfs_result == CBFS_SUCCESS)
+ initialized = 1;
+}
+
+const struct cbfs_header *file_cbfs_get_header(void)
+{
+ if (initialized) {
+ file_cbfs_result = CBFS_SUCCESS;
+ return &cbfs_header;
+ } else {
+ file_cbfs_result = CBFS_NOT_INITIALIZED;
+ return NULL;
+ }
+}
+
+const struct cbfs_cachenode *file_cbfs_get_first(void)
+{
+ if (!initialized) {
+ file_cbfs_result = CBFS_NOT_INITIALIZED;
+ return NULL;
+ } else {
+ file_cbfs_result = CBFS_SUCCESS;
+ return file_cache;
+ }
+}
+
+void file_cbfs_get_next(const struct cbfs_cachenode **file)
+{
+ if (!initialized) {
+ file_cbfs_result = CBFS_NOT_INITIALIZED;
+ file = NULL;
+ return;
+ }
+
+ if (*file)
+ *file = (*file)->next;
+ file_cbfs_result = CBFS_SUCCESS;
+}
+
+const struct cbfs_cachenode *file_cbfs_find(const char *name)
+{
+ struct cbfs_cachenode *cache_node = file_cache;
+
+ if (!initialized) {
+ file_cbfs_result = CBFS_NOT_INITIALIZED;
+ return NULL;
+ }
+
+ while (cache_node) {
+ if (!strcmp(name, cache_node->name))
+ break;
+ cache_node = cache_node->next;
+ }
+ if (!cache_node)
+ file_cbfs_result = CBFS_FILE_NOT_FOUND;
+ else
+ file_cbfs_result = CBFS_SUCCESS;
+
+ return cache_node;
+}
+
+const struct cbfs_cachenode *file_cbfs_find_uncached(uintptr_t end_of_rom,
+ const char *name)
+{
+ u8 *start;
+ u32 size;
+ u32 align;
+ static struct cbfs_cachenode node;
+
+ if (file_cbfs_load_header(end_of_rom, &cbfs_header))
+ return NULL;
+
+ start = (u8 *)(end_of_rom + 1 - cbfs_header.rom_size);
+ size = cbfs_header.rom_size;
+ align = cbfs_header.align;
+
+ while (size >= align) {
+ int result;
+ u32 used;
+
+ result = file_cbfs_next_file(start, size, align, &node, &used);
+
+ if (result < 0)
+ return NULL;
+ else if (result == 0)
+ break;
+
+ if (!strcmp(name, node.name))
+ return &node;
+
+ size -= used;
+ start += used;
+ }
+ file_cbfs_result = CBFS_FILE_NOT_FOUND;
+ return NULL;
+}
+
+const char *file_cbfs_name(const struct cbfs_cachenode *file)
+{
+ file_cbfs_result = CBFS_SUCCESS;
+ return file->name;
+}
+
+u32 file_cbfs_size(const struct cbfs_cachenode *file)
+{
+ file_cbfs_result = CBFS_SUCCESS;
+ return file->data_length;
+}
+
+u32 file_cbfs_type(const struct cbfs_cachenode *file)
+{
+ file_cbfs_result = CBFS_SUCCESS;
+ return file->type;
+}
+
+long file_cbfs_read(const struct cbfs_cachenode *file, void *buffer,
+ unsigned long maxsize)
+{
+ u32 size;
+
+ size = file->data_length;
+ if (maxsize && size > maxsize)
+ size = maxsize;
+
+ memcpy(buffer, file->data, size);
+
+ file_cbfs_result = CBFS_SUCCESS;
+ return size;
+}