This is a quick overview of the very easy process of installing the OpenWRT open source firmware into a LinkSys WRT54GL. Several much more detailed sources of documentation exist on this  , but we include the bare essentials here for simplicity's sake and also because the bulk of OpenWRT does not interest us--it only provides us with a working open-source implementation of an embedded operating system on the router.
Download OpenWRT Binary
Get the latest OpenWRT binary from http://downloads.openwrt.org/whiterussian/newest/bin/. The correct file is openwrt-wrt54g-squashfs.bin
Steps to Install OpenWRT
- Connect to the LinkSys web interface by visiting its address (default 192.168.1.1) in a web browser.
- Upload the OpenWRT file as a "firmware update".
- Watch as your router magically transforms into an OpenWRT-running box.
What to do next?
First it is a good idea to play around with the OpenWRT installation and get a feel for its web interface. You can also login via ssh to the router and poke around its directory structure.
The next big step towards a custom operating system on the router is covered in the next HOWTO in which we will modify the LinkSys hardware