[build] Use SOURCE_DATE_EPOCH for FAT serial number if it exists

Reported-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/util/genfsimg b/src/util/genfsimg
index 0c0692793a085b3426ae27c39a847917769ce743..a981a62d8e92413b18bd32cfb5bb239996e1e25d 100755 (executable)
--- a/src/util/genfsimg
+++ b/src/util/genfsimg
@@ -269,6 +269,10 @@ if [ -n "${FATIMG}" ] ; then
        FATSIZE=$(( FATCYLS * 504 ))
        FATARGS="-s 63 -h 16 -t ${FATCYLS}"
     fi
+    if [ -n "${SOURCE_DATE_EPOCH:-}" ] ; then
+       FATSERIAL=$(( SOURCE_DATE_EPOCH % 100000000 ))
+       FATARGS="${FATARGS} -N ${FATSERIAL}"
+    fi
     truncate -s "${FATSIZE}K" "${FATIMG}"
     mformat -v iPXE -i "${FATIMG}" ${FATARGS} ::
     mcopy -i "${FATIMG}" -s "${FATDIR}"/* ::