ramips: add factory image for ipTIME AX2004M

Unlike the recovery image, this initramfs-factory image can be flashed
using the stock firmware web interface (from any active boot partition),
as well as the bootloader recovery web page. Drop the recovery image in
favor of the factory image.

Installation via stock/recovery web interface:
1.  Flash initramfs-**factory** image through the web page.
2.  Boot into OpenWrt and perform sysupgrade with sysupgrade image.

Signed-off-by: Sungbo Eo <[email protected]>

target/linux/ramips/image/mt7621.mk

@@ -1453,16 +1453,16 @@ define Device/iptime_ax2004m
   KERNEL_LOADADDR := 0x82000000
   KERNEL := kernel-bin | relocate-kernel $(loadaddr-y) | lzma | \
 	fit lzma $$(KDIR)/image-$$(firstword $$(DEVICE_DTS)).dtb
-  IMAGES += recovery.bin
-  IMAGE/recovery.bin := append-kernel | pad-to $$(KERNEL_SIZE) | append-ubi | \
+  ARTIFACTS := initramfs-factory.bin
+  ARTIFACT/initramfs-factory.bin := append-image-stage initramfs-kernel.bin | \
 	check-size | iptime-crc32 ax2004m
   DEVICE_VENDOR := ipTIME
   DEVICE_MODEL := AX2004M
   DEVICE_PACKAGES := kmod-mt7915-firmware kmod-usb3
   DEVICE_COMPAT_VERSION := 2.0
   DEVICE_COMPAT_MESSAGE := NMBM has been newly enabled, and its flash block \
 	mapping might be incompatible with existing installation. \
-	New installation via recovery mode is recommended. \
+	New installation with factory image via recovery mode is recommended. \
 	Use the force flag to proceed sysupgrade anyway.
 endef
 TARGET_DEVICES += iptime_ax2004m

target/linux/ramips/mt7621/base-files/lib/upgrade/platform.sh

@@ -33,6 +33,11 @@ platform_do_upgrade() {
 			fw_setenv --lock / bootImage 0 || exit 1
 		fi
 		;;
+	iptime,ax2004m)
+		if [ "$(fw_printenv -n boot_from 2>/dev/null)" != "firmware1" ]; then
+			fw_setenv boot_from firmware1 || exit 1
+		fi
+		;;
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