From 27a187ed12901f3873755a6d50dcb60c94b30bad Mon Sep 17 00:00:00 2001
From: Martin Kepplinger <martink@posteo.de>
Date: Sun, 15 Apr 2018 09:04:35 +0200
Subject: [PATCH] flashrom_rpi_write: add size check before flashing

flashrom might do it anyways, but we have the read image and can
make sure the user didn't by accident provide the other image, for
example.
---
 flashrom_rpi_write.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/flashrom_rpi_write.sh b/flashrom_rpi_write.sh
index 8563030..360be5c 100755
--- a/flashrom_rpi_write.sh
+++ b/flashrom_rpi_write.sh
@@ -70,6 +70,7 @@ if [ ! "$have_chipname" -gt 0 ] ; then
 fi
 
 INPUT_IMAGE_NAME=$(basename ${INPUT_IMAGE_PATH})
+INPUT_IMAGE_SIZE=$(wc -c <"$INPUT_IMAGE_PATH")
 
 echo "verifying SPI connection by reading"
 TEMP_DIR=`mktemp -d`
@@ -84,6 +85,11 @@ if [ "$have_backupname" -gt 0 ] ; then
 	mv ${TEMP_DIR}/test1.rom ${BACKUPNAME}
 	echo "current image saved as ${BACKUPIMAGE}"
 fi
+TEMP_SIZE=$(wc -c <"$TEMP_DIR/test1.rom")
+if [ ! "$INPUT_IMAGE_SIZE" -eq "$TEMP_SIZE" ] ; then
+	echo "Error: read image (${TEMP_SIZE}) has different size that new image $INPUT_IMAGE_NAME (${INPUT_IMAGE_SIZE})"
+	exit 1
+fi
 rm -rf ${TEMP_DIR}
 
 echo -e "connection ok. flashing ${GREEN}${INPUT_IMAGE_NAME}${NC}"