*** Update: Firmware build and flashed successfully, read the comments on howto ***
Hmm. The WRT54 tomato firmware sources v1.25 doesn't build out-of-the-box for me. Goes into an endless lookup with ever increasing path depths, I killed it off when it seemed to be reconfiguring the kernel the umpteenth time and was at something like make[200]. Something is wrong.
The only reason I'm doing this is that there doesn't seem to be a Tomato 1.25 .trx binary. I only want to try the tomato firmware out on a spare wrt54gl, I don't want to fix their build process thanks.