To replace the Cromwell bios with another more feature rich bios, you have to flash bank0 on the Chameleon using a CD-RW/DVD-RW with the bios. Rename the new bios to LINUXBIO.BIN and burn as ISO9660/Mode1/No Joilet/Disc-at-Once/Finalized CD using a CD-RW or DVD-/+RW. The Cromwell and Xbox is real picky about reading the bios file and require special treatment: Fully erease the RW disc, put a 64 MB+ dummy file (put it before the bios, call it aaa or something) on the disc and try different brands.
Now set your Chameleon to Mode 1 (default) and insert the disc.
|Boot up and wait for the "Please insert CD" message and insert the disc.||If the bios recognized the LINUXBIO.BIN it will start flashing. Do not turn off your Xbox, it should shut down after 30 seconds.||Close up picture when flashing bank0.|
This method only works with the Cromwell bios, you can not flash the bios using this method if you don't have the Cromwell bios in any of the other banks.
Now switch back to Mode 4 if you want have the ability to switch off the mod-chip. You probably thinking it's impossible to change the dip-switches after you have soldered it down, fear not, you can still change the dip-switches without even removing the hard drive or DVD-ROM. Just flip off the top shelf and you can see the dip-switches through the metal-grid on the left side of the Xbox. Use a small screwdriver to align them to the desired posistion. Mode 4 is OFF OFF ON ON (left to right).
|Use a screwdriver to align the dip-switches to the desired position|
Now you should be booting the new bios you flashed to bank0.