util/cbfstool: Add "expand" command to make CBFS span an fmap region

vboot images come with multiple regions carrying CBFS file systems. To
expedite hashing (from slow flash memory), the FW_MAIN_* regions are
truncated since they typically have pretty large unused space at the
end that is of no interest.
For test purposes it can be useful to re-engage that space, so add a
command that creates a new empty file entry covering that area (except
for the last 4 bytes for the master header pointer, as usual).

BUG=b:65853903
BRANCH=none
TEST=`cbfstool test.bin expand -r FW_MAIN_A` creates a new empty file of
the expected size on a Chrome OS firmware image.

Change-Id: I160c8529ce4bfcc28685166b6d9035ade4f6f1d1
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/21598
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Patrick Georgi
2017-09-19 14:39:58 +02:00
parent bea2d75f31
commit 5d982d72be
3 changed files with 59 additions and 0 deletions

View File

@@ -442,6 +442,44 @@ int cbfs_copy_instance(struct cbfs_image *image, struct buffer *dst)
return 0;
}
int cbfs_expand_to_region(struct buffer *region)
{
if (buffer_get(region) == NULL)
return 1;
struct cbfs_image image;
memset(&image, 0, sizeof(image));
if (cbfs_image_from_buffer(&image, region, 0)) {
ERROR("reading CBFS failed!\n");
return 1;
}
uint32_t region_sz = buffer_size(region);
struct cbfs_file *entry;
for (entry = buffer_get(region);
cbfs_is_valid_entry(&image, entry);
entry = cbfs_find_next_entry(&image, entry)) {
/* just iterate through */
}
/* entry now points to the first aligned address after the last valid
* file header. That's either outside the image or exactly the place
* where we need to create a new file.
*/
int last_entry_size = region_sz - ((void *)entry - buffer_get(region))
- cbfs_calculate_file_header_size("") - sizeof(int32_t);
if (last_entry_size > 0) {
cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL,
last_entry_size, "");
/* If the last entry was an empty file, merge them. */
cbfs_walk(&image, cbfs_merge_empty_entry, NULL);
}
return 0;
}
static size_t cbfs_file_entry_metadata_size(const struct cbfs_file *f)
{
return ntohl(f->offset);