fs: Add a Coreboot Filesystem (CBFS) driver and commands

This change adds CBFS support and some commands to use it to u-boot. These
commands are:

cbfsinit - Initialize CBFS support and pull all metadata into RAM. The end of
the ROM is an optional parameter which defaults to the standard 0xffffffff and
can be used to support multiple CBFSes in a system. The last one set up with
cbfsinit is the one that will be used.

cbfsinfo - Print information from the CBFS header.

cbfsls - Print out the size, type, and name of all the files in the current
CBFS. Recognized types are translated into symbolic names.

cbfsload - Load a file from CBFS into memory. Like the similar command for fat
filesystems, you can optionally provide a maximum size.

Support for CBFS is compiled in when the CONFIG_CMD_CBFS option is specified.

The CBFS driver can also be used programmatically from within u-boot.

If u-boot needs something out of CBFS very early before the heap is
configured, it won't be able to use the normal CBFS support which caches some
information in memory it allocates from the heap. The
cbfs_file_find_uncached function searches a CBFS instance without touching
the heap.

Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

2 files changed, 382 insertions, 0 deletions

diff --git a/fs/cbfs/Makefile b/fs/cbfs/Makefile
new file mode 100644
index 0000000..2be8a68
--- /dev/null
+++ b/fs/cbfs/Makefile
@@ -0,0 +1,43 @@
+#
+# 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 $(TOPDIR)/config.mk
+
+LIB	= $(obj)libcbfs.o
+
+COBJS-$(CONFIG_CMD_CBFS)	:= cbfs.o
+
+SRCS	:= $(COBJS-y:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS-y))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
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;
+}