1. How can I remove OpenWrt ?

These steps can also be used to reflash OpenWrt (f. e. when you like to upgrade).

1.1. Using the mtd utility

If you are unhappy with our distribution you can go back to the original firmware you have used before. For that please use the following commands:

cd /tmp
wget http://www.example.org/original.trx
mtd -e linux -r write original.trx linux

Replace the file original.trx with the filename of the firmware you like to install. This will erase the flash (-e linux) and write the new image. The -r will reboot the router after successfully writing the file.

If you get a error message on the above mtd command like "no valid command given" you are using an old version of mtd which doesn't support the -r or -e parameters. Download a newer statically compiled version (mtd.static):

cd /tmp
wget http://downloads.openwrt.org/people/wbx/mtd.static
chmod a+x mtd.static
wget http://www.example.org/original.trx
./mtd.static -e linux -r write original.trx linux

TIP: PLEASE READ - Common mistakes thread section 2 also. It describes when you should use the openwrt-brcm-2.4-squashfs.trx image.

If you only have a Linksys .bin firmware file, this is not a problem, simply cut off the header before using the commands above:

dd bs=32 skip=1 if=original.bin of=original.trx

TIP: If your replacement firmware has a web interface, remember to flush your browser cache, sessions etc. This will avoid misleading 404 errors.

1.2. Using the webif

Since White Russian RC4 you can use the webif to go back to the original firmware. The webif automatically recognizes a firmware image uploaded in BIN or TRX format and converts it accordingly.

Load the webif in your web browser and goto the System / Firmware upgrade page
make sure Erase the JFFS2 partition is checked
choose the BIN or TRX firmware file (downloaded before from the manufactures website onto your PC)
click on the button upload

1.3. Using TFTP

The other way you can use is the TFTP method. The TFTP page explains how to install OpenWrt via TFTP, but this method should also work for other firmware.

$/!\$ Note: On many versions, the TFTP server is only able to accept smaller firmwares at bootup. Firmwares that are over approximately 3 MB will fail with a no space error. If this happens you'll need to either use a different firmware or reflash using the mtd commands above instead.