Experimenting with embedded devices is fun but things not always work as expected. Sometimes you just flash the wrong firmware. So did I. After having done so I furthermore realized that the bootloader in my TL-WA801ND v2.1 was the current one and therefore contains a bug (or maybe it was deliberately crippled?). The impact of this bug was that you’re not able to load something via TFTP from the bootloader. How to unbrick this device? Is it possible at all? To anticipate the answer: It is. But at intermediate level…
I think it might be of interest what I’ve answered in response to one of my commenters. So I decided to put in here as well:
Going back to stock firmware is not that complicated although it can’t be done from the web interface.
First you need to get a stock firmware from TP-Link. I suggest you don’t grab the latest one as it comes along with a new bootloader. The new bootloader is either having a bug or by design crippled but you will no more be able to use TFTP with that one. It’s broken. Take an older one, e.g. TL-WA801ND_V2_120524. Unzip and copy the firmware to the device:
scp -l root wa801nv2_en_3_13_20_up\(120524\).bin IP ADDRESS:/tmp/tplink.bin
Then you need to logon to it via ssh and flash the firmware:
cd /tmp mtd -r write tplink.bin firmware
It will reboot and come back again running the stock firmware.