mkimage -T mxsimage builds u-boot.sb. sb_get_timestamp() reads the wall
clock and sb_prefill_image_header() writes it to the boot image header.
The header digest covers that field, so the sdcard images of mxs differ on
every build.
Add a patch that uses imagetool_get_source_date(), which the other image
tools already use, and keep the wall clock as the fallback.
Tested with the mxsimage configuration of u-boot. Two images are identical
with the same SOURCE_DATE_EPOCH, differ with different values, and still
differ when the variable is not set.
Signed-off-by: John Crispin <john@phrozen.org>
John Crispin
3a33c694aa