misc/57915: [RB] sandpoint/powerpc Use $MKREPRO_TIMESTAMP for repro builds in uBoot images

[jbglaw%lug-owl.de@localhost]

>Number:         57915
>Category:       misc
>Synopsis:       [RB] sandpoint/powerpc Use $MKREPRO_TIMESTAMP for repro builds in uBoot images
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    misc-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 09 07:10:00 +0000 2024
>Originator:     Jan-Benedict Glaw
>Release:        current
>Organization:
>Environment:
>Description:
Building for sandpoint/powerpc, we get embedded build-time timestamps even for reproducible builds. Use $MKREPRO_TIMESTAMP instead.
>How-To-Repeat:
Build twice for sandpoint/powerpc and compare build artifacts.
>Fix:
diff --git a/sys/arch/sandpoint/stand/altboot/Makefile b/sys/arch/sandpoint/stand/altboot/Makefile
index b65c88b9a82b..e0a9ff3d7a3d 100644
--- a/sys/arch/sandpoint/stand/altboot/Makefile
+++ b/sys/arch/sandpoint/stand/altboot/Makefile
@@ -56,13 +56,17 @@ cleandir distclean: .WAIT cleanlibdir
 cleanlibdir:
        -rm -rf lib
 
+.if ${MKREPRO_TIMESTAMP:Uno} != "no"
+MKUBOOTIMAGE_TIMESTAMP=-t "${MKREPRO_TIMESTAMP}"
+.endif
+
 ${PROG}: ${OBJS} ${LIBSA} ${LIBZ} ${LIBKERN}
        ${_MKTARGET_LINK}
        ${LD} -N -Ttext ${RELOC} -Bstatic -e ${ENTRY} -o ${PROG} \
            ${OBJS} ${LIBSA} ${LIBZ} ${LIBKERN}
        ${OBJCOPY} -S -O binary ${PROG} ${PROG}.bin
        ${TOOL_MKUBOOTIMAGE} -A powerpc -T kernel -C none -O linux \
-           -a 0x${RELOC} -n ${PROG} ${PROG}.bin ${PROG}.img
+           -a 0x${RELOC} ${MKUBOOTIMAGE_TIMESTAMP} -n ${PROG} ${PROG}.bin ${PROG}.img
 
 VERSIONFLAGS+=-k
 .include "${S}/conf/newvers_stand.mk"