cbfstool: Use cbfs_image API for "remove" command.

To delete a component (file) from existing CBFS ROM image.

To test:
	cbfstool coreboot.rom remove -n fallback/romstage
	# and compare with old cbfstool output result.

Change-Id: If39ef9be0b34d8e3df77afb6c9f944e02f08bc4e
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2208
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/util/cbfstool/cbfs_image.c b/util/cbfstool/cbfs_image.c
index 7d08b43..cc4460c 100644
--- a/util/cbfstool/cbfs_image.c
+++ b/util/cbfstool/cbfs_image.c
@@ -98,6 +98,13 @@
 	return lookup_type_by_name(types_cbfs_compression, name, unknown);
 }
 
+/* CBFS image */
+
+static int cbfs_calculate_file_header_size(const char *name) {
+	return (sizeof(struct cbfs_file) +
+		align_up(strlen(name) + 1, CBFS_FILENAME_ALIGN));
+}
+
 int cbfs_image_from_file(struct cbfs_image *image, const char *filename) {
 	if (buffer_from_file(&image->buffer, filename) != 0)
 		return -1;
@@ -166,6 +173,29 @@
 	return 0;
 }
 
+int cbfs_remove_entry(struct cbfs_image *image, const char *name) {
+	struct cbfs_file *entry, *next;
+	size_t len;
+	entry = cbfs_get_entry(image, name);
+	if (!entry) {
+		ERROR("CBFS file %s not found.\n", name);
+		return -1;
+	}
+	next = cbfs_find_next_entry(image, entry);
+	assert(next);
+	DEBUG("cbfs_remove_entry: Removed %s @ 0x%x\n",
+	      CBFS_NAME(entry), cbfs_get_entry_addr(image, entry));
+	entry->type = htonl(CBFS_COMPONENT_DELETED);
+	len = (cbfs_get_entry_addr(image, next) -
+	       cbfs_get_entry_addr(image, entry));
+	entry->offset = htonl(cbfs_calculate_file_header_size(""));
+	entry->len = htonl(len - ntohl(entry->offset));
+	memset(CBFS_NAME(entry), 0, ntohl(entry->offset) - sizeof(*entry));
+	memset(CBFS_SUBHEADER(entry), CBFS_CONTENT_DEFAULT_VALUE,
+	       ntohl(entry->len));
+	return 0;
+}
+
 int cbfs_print_header_info(struct cbfs_image *image) {
 	char *name = strdup(image->buffer.name);
 	assert(image && image->header);