futility: flashrom_drv: support partial write for multiple regions

When we have multiple regions to update, invoking flashrom_write_image
multiple times will take much longer because for each write it has to
read the whole flash, write and then verify whole flash (also timer
calibration and programmer init/shutdown every time).

As a result, we want to support writing multiple regions - just like
that flashrom can take arbitrary numbers of "-i REGION".

This change only extended flashrom_write_image, and the firmware updater
is calling flashrom_drv multiple times. That will be addressed in the
follow up changes.

BUG=b:221137867
TEST=build; and run test
BRANCH=None

Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Change-Id: Id335cc9f816f1384f1886422efa97fe2c7b81aec
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3490388
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/futility/updater_utils.h b/futility/updater_utils.h
index 4ab61c93..3eb1d33c 100644
--- a/futility/updater_utils.h
+++ b/futility/updater_utils.h
@@ -93,13 +93,14 @@ const char *get_firmware_image_temp_file(const struct firmware_image *image,
 					 struct tempfile *tempfiles);
 
 /*
- * Writes a section from given firmware image to system firmware.
- * If section_name is NULL, write whole image.
+ * Writes sections from a given firmware image to the system firmware.
+ * Regions should be NULL for writing the whole image, or a list of
+ * FMAP section names (and ended with a NULL).
  * Returns 0 if success, non-zero if error.
  */
 int write_system_firmware(const struct firmware_image *image,
 			  const struct firmware_image *diff_image,
-			  const char *section_name,
+			  const char * const sections[],
 			  struct tempfile *tempfiles,
 			  int do_verify, int retries, int verbosity);