I wanted to update the firmware on my router, but I ended up bricking it. After some panic and research I found these three solutions:
2. Use JTag
3. unicorn (lives in the legends) https://forum.openwrt.org/viewtopic.php?id=27665
I had chose the first, I have a USB-serial converter (UART, Cp2102), on Windows:
Preparation: You will need a usb-serial converter, some program that will support serial communication(I had picked Putty), a program that will help you upload a file via TFTP, and the right firmware.
1. Remove the case of the router.
2. Here you can see the serial port. I plugged the right cables to the right place. From up to down:
1 – GND
2 – NC
3 – RX
4 – TX
5 – 3.3V
I only used, the RX, TX and the GND, in my case it was enough ( the PC’s usb provided me the power)
3. When you connected everything, run the Putty, and set the serial parameters(choose the right com port, in my case it was com 4, use 115200 baud for the speed).
4. Turn on the router, then connect the Putty to the router, and cancel the uboot(with ctrl+c keyboard combination).
5. If you did right you will get this prompt:
6. Prepare the router for the upload, give this command:
upgrade code.bin #the code.bin will be the filename that it will wait for upload. You will get back something like this:
check link duplex:Full/speed:100
dup 1 speed 100
Tftpd start listening on port!
Load address: 0×80060000
7. Rename the firmware to code.bin. Set your PC IP on same network to some address in range 192.168.1.[2-254]. Now run the TFTP software. The host will be 192.168.1.1, browse the file, and start the upload (you will not need the password).
8. If you did everything right you can see the Putty’s window it will start the upload, and do the flashing. After about 10 mins, it is done. You will get back the console. Now you can reboot the device and use it as you want.