mediatek: Add support for Xiaomi Redmi Router AX6S

Also known as the "Xiaomi Router AX3200" in western markets,
but only the AX6S is widely installation-capable at this time.

SoC: MediaTek MT7622B
RAM: DDR3 256 MiB (ESMT M15T2G16128A)
Flash: SPI-NAND 128 MiB (ESMT F50L1G41LB or Gigadevice GD5F1GQ5xExxG)
WLAN: 2.4/5 GHz 4T4R
2.4 GHz: MediaTek MT7622B
5 GHz: MediaTek MT7915E
Ethernet: 4x 10/100/1000 Mbps
Switch: MediaTek MT7531B
LEDs/Keys: 2/2 (Internet + System LED, Mesh button + Reset pin)
UART: Marked J1 on board VCC RX GND TX, beginning from "1". 3.3v, 115200n8
Power: 12 VDC, 1.5 A

Notes:
U-Boot passes through the ethaddr from uboot-env partition,
but also has been known to reset it to a generic mac address
hardcoded in the bootloader.

However, bdata is also populated with the ethernet mac addresses,
but is also typically never written to. Thus this is used instead.

Installation:
1. Flash stock Xiaomi "closed beta" image labelled
'miwifi_rb03_firmware_stable_1.2.7_closedbeta.bin'.
(MD5: 5eedf1632ac97bb5a6bb072c08603ed7)

2. Calculate telnet password from serial number and login

3. Execute commands to prepare device
nvram set ssh_en=1
nvram set uart_en=1
nvram set boot_wait=on
nvram set flag_boot_success=1
nvram set flag_try_sys1_failed=0
nvram set flag_try_sys2_failed=0
nvram commit

4. Download and flash image
On computer:
python -m http.server
On router:
cd /tmp
wget http://<IP>:8000/factory.bin
mtd -r write factory.bin firmware

Device should reboot at this point.

Reverting to stock:
Stock Xiaomi recovery tftp that accepts their signed images,
with default ips of 192.168.31.1 + 192.168.31.100.
Stock image should be renamed to tftp server ip in hex (Eg. C0A81F64.img)
Triggered by holding reset pin on powerup.

A simple implementation of this would be via dnsmasq's
dhcp-boot option or using the vendor's (Windows only)
recovery tool available on their website.

Signed-off-by: Richard Huynh <voxlympha@gmail.com>

3 files changed, 18 insertions, 2 deletions

diff --git a/target/linux/mediatek/mt7622/base-files/etc/board.d/01_leds b/target/linux/mediatek/mt7622/base-files/etc/board.d/01_leds
index 65a81df8da..5c32918d35 100644
--- a/target/linux/mediatek/mt7622/base-files/etc/board.d/01_leds
+++ b/target/linux/mediatek/mt7622/base-files/etc/board.d/01_leds
@@ -10,6 +10,9 @@ linksys,e8450|\
 linksys,e8450-ubi)
 	ucidef_set_led_netdev "wan" "WAN" "inet:blue" "wan"
 	;;
+xiaomi,redmi-router-ax6s)
+	ucidef_set_led_netdev "wan" "WAN" "blue:net" "wan"
+	;;
 esac
 
 board_config_flush
diff --git a/target/linux/mediatek/mt7622/base-files/etc/board.d/02_network b/target/linux/mediatek/mt7622/base-files/etc/board.d/02_network
index 4649d0dc57..c55fcbee2e 100644
--- a/target/linux/mediatek/mt7622/base-files/etc/board.d/02_network
+++ b/target/linux/mediatek/mt7622/base-files/etc/board.d/02_network
@@ -24,6 +24,9 @@ mediatek_setup_interfaces()
 	ubnt,unifi-6-lr-ubootmod)
 		ucidef_set_interface_lan "eth0"
 		;;
+	xiaomi,redmi-router-ax6s)
+		ucidef_set_interfaces_lan_wan "lan1 lan2 lan3" wan
+		;;
 	*)
 		ucidef_add_switch "switch0" \
 				  "0:lan" "1:lan" "2:lan" "3:lan" "4:wan" "6u@eth0" "5u@eth1"
@@ -35,14 +38,22 @@ mediatek_setup_macs()
 {
 	local board="$1"
 	local lan_mac=""
+	local wan_mac=""
+	local label_mac=""
 
 	case $board in
 	ruijie,rg-ew3200gx-pro)
 		lan_mac=$(macaddr_add $(get_mac_label) 1)
 		;;
+	xiaomi,redmi-router-ax6s)
+		wan_mac=$(mtd_get_mac_ascii bdata ethaddr_wan)
+		label_mac=$wan_mac
+		;;
 	esac
 
 	[ -n "$lan_mac" ] && ucidef_set_interface_macaddr "lan" $lan_mac
+	[ -n "$wan_mac" ] && ucidef_set_interface_macaddr "wan" $wan_mac
+	[ -n "$label_mac" ] && ucidef_set_label_macaddr $label_mac
 }
 
 board_config_update
diff --git a/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh b/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
index fbca6ef0f7..f54665dfa1 100755
--- a/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
+++ b/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
@@ -45,7 +45,8 @@ platform_do_upgrade() {
 		default_do_upgrade "$1"
 		;;
 	mediatek,mt7622-rfb1-ubi|\
-	totolink,a8000ru)
+	totolink,a8000ru|\
+	xiaomi,redmi-router-ax6s)
 		nand_do_upgrade "$1"
 		;;
 	*)
@@ -67,7 +68,8 @@ platform_check_image() {
 		buffalo_check_image "$board" "$magic" "$1" || return 1
 		;;
 	mediatek,mt7622-rfb1-ubi|\
-	totolink,a8000ru)
+	totolink,a8000ru|\
+	xiaomi,redmi-router-ax6s)
 		nand_do_platform_check "$board" "$1"
 		;;
 	*)