fitblk: move shell functions to common file

Move shell functions used for sysupgrade into /lib/upgrade/fit.sh.
Introduce improved fitblk boot device detection function which
works also in case ubiblock devices have not yet been created or
even UBI itself not yet being attached.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

package/utils/fitblk/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fitblk
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 PKG_LICENSE:=GPL-2.0-only
 PKG_MAINTAINER:=Daniel Golle <daniel@makrotopia.org>
 
@@ -36,6 +36,8 @@ endef
 define Package/fitblk/install
 	$(INSTALL_DIR) $(1)/usr/sbin
 	$(INSTALL_BIN) $(PKG_BUILD_DIR)/fitblk $(1)/usr/sbin/
+	$(INSTALL_DIR) $(1)/lib/upgrade
+	$(INSTALL_DATA) ./files/fit.sh $(1)/lib/upgrade
 endef
 
 $(eval $(call BuildPackage,fitblk))

package/utils/fitblk/files/fit.sh

@@ -0,0 +1,63 @@
+export_fitblk_bootdev() {
+	[ -e /sys/firmware/devicetree/base/chosen/rootdisk ] || return
+
+	local rootdisk="$(cat /sys/firmware/devicetree/base/chosen/rootdisk)"
+	local handle bootdev
+
+	for handle in /sys/class/mtd/mtd*/of_node/volumes/*/phandle; do
+		[ ! -e "$handle" ] && continue
+		if [ "$rootdisk" = "$(cat "$handle")" ]; then
+			if [ -e "${handle%/phandle}/volname" ]; then
+				export CI_KERNPART="$(cat "${handle%/phandle}/volname")"
+			elif [ -e "${handle%/phandle}/volid" ]; then
+				export CI_KERNVOLID="$(cat "${handle%/phandle}/volid")"
+			else
+				return
+			fi
+			export CI_UBIPART="$(cat "${handle%%/of_node*}/name")"
+			export CI_METHOD="ubi"
+			return
+		fi
+	done
+
+	for handle in /sys/class/mtd/mtd*/of_node/phandle; do
+		[ ! -e "$handle" ] && continue
+		if [ "$rootdisk" = "$(cat $handle)" ]; then
+			bootdev="${handle%/of_node/phandle}"
+			bootdev="${bootdev#/sys/class/mtd/}"
+			export PART_NAME="/dev/$bootdev"
+			export CI_METHOD="default"
+			return
+		fi
+	done
+
+	for handle in /sys/class/block/*/of_node/phandle; do
+		[ ! -e "$handle" ] && continue
+		if [ "$rootdisk" = "$(cat $handle)" ]; then
+			bootdev="${handle%/of_node/phandle}"
+			bootdev="${bootdev#/sys/class/block/}"
+			export EMMC_KERN_DEV="/dev/$bootdev"
+			export CI_METHOD="emmc"
+			return
+		fi
+	done
+}
+
+fit_do_upgrade() {
+	export_fitblk_bootdev
+	[ -n "$CI_METHOD" ] || return 1
+	[ -e /dev/fit0 ] && fitblk /dev/fit0
+	[ -e /dev/fitrw ] && fitblk /dev/fitrw
+
+	case "$CI_METHOD" in
+	emmc)
+		emmc_do_upgrade "$1"
+		;;
+	default)
+		default_do_upgrade "$1"
+		;;
+	ubi)
+		nand_do_upgrade "$1"
+		;;
+	esac
+}