sifiveu: use the legacy-sdcard upgrade helper

Share the partition layout check and disk write with the other
whole-disk image targets, which keeps user partitions from being erased.

Signed-off-by: John Audia <therealgraysky@proton.me>

target/linux/sifiveu/Makefile

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=riscv64
 BOARD:=sifiveu
 BOARDNAME:=SiFive U-based RISC-V boards
-FEATURES:=ext4
+FEATURES:=ext4 legacy-sdcard
 KERNELNAME:=Image dtbs
 SUBTARGETS:=generic
 

target/linux/sifiveu/base-files/lib/upgrade/platform.sh

@@ -1,28 +1,5 @@
 platform_check_image() {
-	local diskdev partdev diff
-
-	export_bootdevice && export_partdevice diskdev 0 || {
-		echo "Unable to determine upgrade device"
-		return 1
-	}
-
-	get_partitions "/dev/$diskdev" bootdisk
-
-	#extract the boot sector from the image
-	get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b 2>/dev/null
-
-	get_partitions /tmp/image.bs image
-
-	#compare tables
-	diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
-
-	rm -f /tmp/image.bs /tmp/partmap.bootdisk /tmp/partmap.image
-
-	if [ -n "$diff" ]; then
-		echo "Partition layout has changed. Full image will be written."
-		ask_bool 0 "Abort" && exit 1
-		return 0
-	fi
+	legacy_sdcard_check_image "$1"
 }
 
 platform_copy_config() {
@@ -36,51 +13,5 @@ platform_copy_config() {
 }
 
 platform_do_upgrade() {
-	local diskdev partdev diff
-
-	export_bootdevice && export_partdevice diskdev 0 || {
-		echo "Unable to determine upgrade device"
-		return 1
-	}
-
-	sync
-
-	if [ "$UPGRADE_OPT_SAVE_PARTITIONS" = "1" ]; then
-		get_partitions "/dev/$diskdev" bootdisk
-
-		#extract the boot sector from the image
-		get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
-
-		get_partitions /tmp/image.bs image
-
-		#compare tables
-		diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
-	else
-		diff=1
-	fi
-
-	if [ -n "$diff" ]; then
-		get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
-
-		# Separate removal and addtion is necessary; otherwise, partition 1
-		# will be missing if it overlaps with the old partition 2
-		partx -d - "/dev/$diskdev"
-		partx -a - "/dev/$diskdev"
-
-		return 0
-	fi
-
-	#iterate over each partition from the image and write it to the boot disk
-	while read part start size; do
-		if export_partdevice partdev $part; then
-			echo "Writing image to /dev/$partdev..."
-			get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
-		else
-			echo "Unable to find partition $part device, skipped."
-		fi
-	done < /tmp/partmap.image
-
-	#copy partition uuid
-	echo "Writing new UUID to /dev/$diskdev..."
-	get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
+	legacy_sdcard_do_upgrade "$1"
 }