cbfstool/add-payload: initialize segment headers to 0

Some types of payload segment headers do not use all fields.
If these unused fields are not initialized to 0, they can
cause problems in other software which consumes payloads.

For example, PAYLOAD_SEGMENT_ENTRY does not use the compression
field.  If it happens to be a non-existent compression type,
the 'cbfstool extract' command fails.

BUG=https://ticket.coreboot.org/issues/170
TEST=cbfstool tianocore.cbfs create -s 2097152 -m x86
     cbfstool tianocore.cbfs add-payload -f UEFIPAYLOAD.fd -n payload -c lzma -v
     xxd tianocore.cbfs | head  # visually inspect compression field for 0

Change-Id: I359ed117ab4154438bac7172aebf608f7a022552
Signed-off-by: kitching@google.com
Reviewed-on: https://review.coreboot.org/27540
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
1 file changed