MediaTek MT7621 U-Boot with Failsafe Mode

Online Build

Flash Type
NOR Flash / NAND Flash / NAND Flash with NMBM support

MTD Partition Table
example: 192k(u-boot),64k(u-boot-env),64k(factory),-(firmware)
notice: u-boot and firmware partitions are essential

Kernel Load Address
equal to the sum of all partition size before firmware in hexadecimal

Reset Button GPIO
GPIO pin number of the reset button
notice: if not set, you can't press reset button to enter failsafe mode

System LED GPIO
GPIO pin number of the status LED
notice: if not set, status LED won't blink when you press reset button

CPU Frequency
default value is 880 (MHz).
notice: Overclock may cause the system to fail to boot or overheat.

DRAM Frequency
default 800 (MT/s) for DDR2 and 1200 (MT/s) for DDR3.
notice: if your board is unstable, try lowering it.

Prefered DDR Init Parameters
DRAM specific model or type and size
notice: DDR3-128MiB-KGD is for MT7621DAT (internal integrated 128MiB RAM)

Use Old DDR Timing Parameters
DDR Timing Parameters used in ralink U-Boot 1.1.3
notice: do not select it if your board is working properly

Baud Rate
TTL serial port baud rate, 57600 or 115200

Flash u-boot-mt7621.bin into board.
Set computer IP address to 192.168.1.2 and Netmask to 255.255.255.0.
Gateway 192.168.1.1 is optional.
Remove the power supply, press and hold the reset button, plug in the
power supply. And then you can choose:

a) Release the button after the status LED blinks at least 1 second
(blink 5 times), then you will enter into WebUI recovery mode. You can
open http://192.168.1.1 in the browser to upload firmware.

b) Hold the button until the status LED no longer blinks (blink 6 seconds
in total), then you will enter into TFTP download mode. You can upload
initramfs kernel image recovery.bin via TFTP server such as tftpd64.