ath79: move image check for devices with RedBoot

Don't comence the switch to RAMFS when the image format is wrong. This
led to rebooting the device, which could lead to false impression that
upgrade succeded.
Being here, factor out the code responsible for upgrading RedBoot
devices to separate file.

Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>

target/linux/ath79/generic/base-files/lib/upgrade/platform.sh

@@ -8,35 +8,19 @@ REQUIRE_IMAGE_METADATA=1
 RAMFS_COPY_BIN='fw_printenv fw_setenv'
 RAMFS_COPY_DATA='/etc/fw_env.config /var/lock/fw_printenv.lock'
 
-redboot_fis_do_upgrade() {
-	local append
-	local sysup_file="$1"
-	local kern_part="$2"
-	local magic=$(get_magic_word "$sysup_file")
-
-	if [ "$magic" = "7379" ]; then
-		local board_dir=$(tar tf $sysup_file | grep -m 1 '^sysupgrade-.*/$')
-
-		[ -f "$UPGRADE_BACKUP" ] && append="-j $UPGRADE_BACKUP"
-
-		if grep -q "mtd1.*loader" /proc/mtd; then
-			tar xf $sysup_file ${board_dir}kernel ${board_dir}root -O | \
-				mtd -r $append write - loader:firmware
-
-		else
-			local kern_length=$(tar xf $sysup_file ${board_dir}kernel -O | wc -c)
-
-			tar xf $sysup_file ${board_dir}kernel ${board_dir}root -O | \
-				mtd -r $append -F$kern_part:$kern_length:0x80060000,rootfs write - $kern_part:rootfs
-		fi
-	else
-		echo "Unknown image, aborting!"
-		return 1
-	fi
-}
-
 platform_check_image() {
-	return 0
+	local board=$(board_name)
+
+	case "$board" in
+	jjplus,ja76pf2|\
+	ubnt,routerstation|\
+	ubnt,routerstation-pro)
+		platform_check_image_redboot_fis "$1"
+		;;
+	*)
+		return 0
+		;;
+	esac
 }
 
 platform_do_upgrade() {
@@ -45,7 +29,7 @@ platform_do_upgrade() {
 	case "$board" in
 	adtran,bsap1800-v2|\
 	adtran,bsap1840)
-		redboot_fis_do_upgrade "$1" vmlinux_2
+		platform_do_upgrade_redboot_fis "$1" vmlinux_2
 		;;
 	allnet,all-wap02860ac|\
 	araknis,an-300-ap-i-n|\
@@ -66,7 +50,7 @@ platform_do_upgrade() {
 		platform_do_upgrade_failsafe_datachk "$1"
 		;;
 	jjplus,ja76pf2)
-		redboot_fis_do_upgrade "$1" linux
+		platform_do_upgrade_redboot_fis "$1" linux
 		;;
 	openmesh,a40|\
 	openmesh,a60|\
@@ -98,7 +82,7 @@ platform_do_upgrade() {
 		;;
 	ubnt,routerstation|\
 	ubnt,routerstation-pro)
-		redboot_fis_do_upgrade "$1" kernel
+		platform_do_upgrade_redboot_fis "$1" kernel
 		;;
 	*)
 		default_do_upgrade "$1"

target/linux/ath79/generic/base-files/lib/upgrade/redboot-fis.sh

@@ -0,0 +1,31 @@
+platform_check_image_redboot_fis() {
+	if [ "$(get_magic_word "$1")" != "7379" ]; then
+		v "Unknown image format, aborting!"
+		return 1
+	else
+		return 0
+	fi
+}
+
+platform_do_upgrade_redboot_fis() {
+	local append
+	local sysup_file="$1"
+	local kern_part="$2"
+
+	if [ "$(get_magic_word "$sysup_file")" = "7379" ]; then
+		local board_dir=$(tar tf $sysup_file | grep -m 1 '^sysupgrade-.*/$')
+
+		[ -f "$UPGRADE_BACKUP" ] && append="-j $UPGRADE_BACKUP"
+
+		if grep -q "mtd1.*loader" /proc/mtd; then
+			tar xf $sysup_file ${board_dir}kernel ${board_dir}root -O | \
+				mtd -r $append write - loader:firmware
+
+		else
+			local kern_length=$(tar xf $sysup_file ${board_dir}kernel -O | wc -c)
+
+			tar xf $sysup_file ${board_dir}kernel ${board_dir}root -O | \
+				mtd -r $append -F$kern_part:$kern_length:0x80060000,rootfs write - $kern_part:rootfs
+		fi
+	fi
+}