ramips: add support for I-O DATA WN-DX1167R

I-O DATA WN-DX1167R is a 2.4/5 GHz band 11ac rotuer, based on MediaTek
MT7621A.

Specification:

- SoC		: MediaTek MT7621A
- RAM		: DDR3 128 MiB
- Flash		: NAND 128 MiB
- WLAN		: MediaTek MT7615D (2.4/5 GHz, 2T2R)
- Ethernet	: 5x 10/100/1000 Mbps
  - Switch	: MediaTek MT7621A (MT7530)
- LEDs/Input	: 2x/3x (2x buttons, 1x slide-switch)
- UART		: through-hole on PCB
  - J5: Vcc, TX, RX, NC, GND
  - 57600 bps

Flash instruction using initramfs image:

1. Boot WN-DX1167R normally
2. Access to "http://192.168.0.1/" and open firmware update page
("ファームウェア")
3. Select the OpenWrt initramfs image and click update ("更新")
button to perform firmware update
4. On the initramfs image, perform sysupgrade with squashfs-sysupgrade
image
5. Wait ~120 seconds to complete flashing

Notes:

- configuration in DeviceTree of DBDC (Dual-Band-Dual-Concurrent) mode
for MT7615D chip is not supported in mt76 driver
- last 0x80000 (512 KiB) in NAND flash is not used on stock firmware
- stock firmware requires "customized uImage header" by MSTC
(MitraStar Technology Corp.), but U-Boot doesn't
  - uImage magic (0x0 - 0x3) : 0x434F4D43 (COMC)
  - header crc32 (0x4 - 0x7) : with data length and data crc32
  - image name (0x20 - 0x37) : model ID and firmware versions
  - data length (0x38 - 0x3b): kernel + rootfs
  - data crc32 (0x3c - 0x3f) : kernel + rootfs

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Reviewed-by: Sungbo Eo <mans0n@gorani.run>

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

@@ -0,0 +1,55 @@
+#
+# Copyright (C) 2019 OpenWrt.org
+#
+
+. /lib/functions.sh
+
+iodata_mstc_prepare_fail() {
+	echo "failed to check and prepare the environment, rebooting..."
+	umount -a
+	reboot -f
+}
+
+# I-O DATA devices manufactured by MSTC (MitraStar Technology Corp.)
+# have two important flags:
+# - bootnum: switch between two os images
+#     use 1st image in OpenWrt
+# - debugflag: enable/disable debug
+#     users can interrupt Z-Loader for recovering the device if enabled
+iodata_mstc_upgrade_prepare() {
+	local persist_mtd="$(find_mtd_part persist)"
+	local factory_mtd="$(find_mtd_part factory)"
+
+	if [ -z "$persist_mtd" -o -z "$factory_mtd" ]; then
+		echo 'cannot find mtd partition(s), "factory" or "persist"'
+		iodata_mstc_prepare_fail
+	fi
+
+	local bootnum=$(hexdump -s 4 -n 1 -e '"%x"' ${persist_mtd})
+	local debugflag=$(hexdump -s 65141 -n 1 -e '"%x"' ${factory_mtd})
+
+	if [ "$bootnum" != "1" -a "$bootnum" != "2" ]; then
+		echo "failed to get bootnum, please check the value at 0x4 in ${persist_mtd}"
+		iodata_mstc_prepare_fail
+	fi
+	if [ "$debugflag" != "0" -a "$debugflag" != "1" ]; then
+		echo "failed to get debugflag, please check the value at 0xFE75 in ${factory_mtd}"
+		iodata_mstc_prepare_fail
+	fi
+	echo "current: bootnum => ${bootnum}, debugflag => ${debugflag}"
+
+	if [ "$bootnum" = "2" ]; then
+		if ! (echo -ne "\x01" | dd bs=1 count=1 seek=4 conv=notrunc of=${persist_mtd} 2>/dev/null); then
+			echo "failed to set bootnum"
+			iodata_mstc_prepare_fail
+		fi
+		echo "### switch to 1st os-image on next boot ###"
+	fi
+	if [ "$debugflag" = "0" ]; then
+		if ! (echo -ne "\x01" | dd bs=1 count=1 seek=65141 conv=notrunc of=${factory_mtd} 2>/dev/null); then
+			echo "failed to set debugflag"
+			iodata_mstc_prepare_fail
+		fi
+		echo "### enable debug ###"
+	fi
+}

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

@@ -53,6 +53,10 @@ platform_do_upgrade() {
 	xiaomi,mir3p)
 		nand_do_upgrade "$1"
 		;;
+	iodata,wn-dx1167r)
+		iodata_mstc_upgrade_prepare
+		nand_do_upgrade "$1"
+		;;
 	ubiquiti,edgerouterx|\
 	ubiquiti,edgerouterx-sfp)
 		platform_upgrade_ubnt_erx "$1"