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;
+}