tl;dr: built/installed kernel .debs based on linux-omap git tree--it smells burnt, but after flashing 2.6.28 it seems all ok again.

I built kernel packages using the upstream kernel_2.6.28-20094102.3+0m5 sources, bumped the version, installed the debs (which reflash), rebooted, and had a working system. All ok, but no changes.

I then decided to go for it and grabbed the latest linux-omap git tree (based on 2.6.32) and built packages of that. After one patchlet I was able to build packages, ala kernel_2.6.32-0.6833f1a8_armel.deb.

I flashed this successfully, but on reboot it appeared to load but then the screen went bad and it seemed to smell. :O I yanked the battery.

I then reflashed the previous zImage with maemo_flasher-3.5 (I had previously made a copy of /lib/modules/2.6.28-omap1 so the modules were still there) and it all came back A-OK.

I'm going to enable the framebuffer console to see if it tells me anything. I'm also going to go thru the various patches in 2.6.28 to actually see WTF is going on there.

It does look like linux-omap is Nokia's "upstream" AFAICT, but I'm not sure where else they are drawing from. I don't know of any "N900 git" tree of any sort, but that would be just fantastic.

Any kernel folks that can give a pointer or two? (well, other than "don't do that" heh)

I will be continually updating this with more info:
http://wiki.maemo.org/User:Jebba#Kernel

On that page I'll also do a larger write up on working with the 2.6.28 kernel, since that one actually does work.

There is a wee bit of info (or at least a play by play...) in the #maemo-devel IRC logs:
http://mg.pov.lt/maemo-devel-irclog/...12-09.log.html

Have fun,

-Jeff