[PATCH openbmc v2 18/34] update: Skip calling flashcp for empty files

[OpenBMC Patches]

From: "Milton D. Miller II" <miltonm at us.ibm.com>

Note explicitly when an empty image is provided that will not
alter a flash partition.

While using flashcp on an empty file succeeds and does not alter
the flash, it may be confusing to see 0/0 messages for the erase,
write, and verify phases.

These empty files are used to trigger the save and restore phases
and may also be used by developers to cause the update to fail
and break into a shell at shutdown for maintence.

Signed-off-by: Milton Miller <miltonm at us.ibm.com>
---
 .../recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh      | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
index edaf195..aa8fd89 100755
--- a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
+++ b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
@@ -136,6 +136,12 @@ done
 
 for f in $image*
 do
+	if test ! -s $f
+	then
+		echo "Skipping empty update of ${f#$image}."
+		rm $f
+		continue
+	fi
 	m=$(findmtd ${f#$image})
 	echo "Updating ${f#$image}..."
 	flashcp -v $f /dev/$m && rm $f
-- 
2.7.1