https://wiki.archlinux.org/index.php/An ... the_sdcardYou could try it yourself with this. it's essentially 3 steps : make a chroot environment in separate partition of sdcard, then add some tweak, and finally tell kernel via cmdline to use the chroot environment instead of default android environment.
following is my personal experience, just FYI
Using LG Optimus One(not worldwide version P500, it is Korean version LU3700), I followed xda thread. but instead of debootstraping, I just unzipped Raspberry pi ArchARM image into SD card.
All things were going well until making chroot environment, but eventually, my O1 failed to boot linux.
The problem was fastboot behaving weird; When I tried to manipulate cmdline slightly(e.g. adding "quiet" or something like that), /proc/cmdline seemed to be totally ignoring me. When I tried to give bigger changes, like "init=blah blah" it just didn't try to boot. Normally the screen goes black before rebooting but it simply froze with fastboot screen.
I also tried to give cmdline via
repacking kernel, but it refused to boot unless I packed the kernel WITHOUT a cmdline, although stock kernel DOES have cmdline. When I tried to boot the phone with a kernel repacked with cmdline, the screen would go black for ~10 secs, then rebooted, again ignoring my cmdline. the last chance was to force cmdline or use kexec with a fresh kernel, but it also failed. I'm not sure whether it was the faulty cmdline or my lack of cross-compiling ability