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

jebba, what are you doing this for? You really want to fry your device?

Oh, I don't want to fry it at all!

I can learn a lot about a device by poking around with the kernel. Also, I would like to see if things like the front facing camera are getting fixed in more recent kernels (as one simple example).

Oh and it's interesting to see how much Nokia has pushed upstream and mainlined the n900...

But mostly for the hell of it.

-Jeff

It won't fry the device, and it'll be possible to recover (although it's best to experiment with own kernels in a boot-from-SD scenario).

These are Linux devices. We build kernels for them. As for the Nokia Internet tablets this has been done back since the 770.

Dude you are heroic.

Many companies develop open source devices.

But when you try and do it yourself usually:
(a) No documentation or woefully out-of-date or plain make no sense
(b) The sources and files needed seem to incomplete

This means you cannot reproduce the steps to make your custom device.

I went to your "progress" link and you have done some fantastic work.

Many people will find what you have done interesting and useful.

Hopefully you will get a lot of interest and people to help you.

Good Luck and please don't damage your N900 !

Ya, I wasn't expecting to fry it, I just assumed it would boot or just get a black screen or whatever. But I'm 100% sure it smelled of burnt electronics (and still does a bit), and that (somewhat) surprised me.

It would be nice to put a proper boot manager on here and boot from SD like you say.

Thx,

-Jeff

Hm, it's possible that your kernel is unable to use any of the power saving features in the standard kernel, e.g. powering off parts of the OMAP SoC not in use, reducing voltage, reducing frequency etc. I'm guessing a bit (from knowledge about other OMAP3 SoC sets) that it could well be using 500 mA or more with "everything on". That would be a couple of watts at least, which could be a bit hot inside the little phone.

Feeding in a voltage higher than the chips maximum ratings is entirely possible with the PMIC. Oh the joys of feeding in 5V to a 3.3V part.

Check out arch/arm/mach-omap2/board-rx51* .

The PM related stuff is twl4030. The omap3 can have different signals for a given ball (pin) and there is some macro to change that pin muxing. The pin assignments should be checked as well.

drivers/input/touchscreen/tsc2005.c was dropped after 2.6.29 from the linux-omap tree:

So post 2.6.29, no touchscreen.

It looks like they are trying to get it back in again though:

http://patchwork.kernel.org/patch/57577/

http://patchwork.kernel.org/patch/57574/

Does anyone know of a Aaro Koskinen (Aaro.Koskinen@nokia.com) kernel tree? That one would be great to use. Or even any other tree besides linux-omap, which is definitely lagging behind what @nokians are using.

Hi there.

Has there been any progress on getting a vanilla (read: Linus's tree) with the patches for the N900 forward-ported? I would be willing to lend a hand here, in smaller steps than the jump from the 2.6.28.x to 2.6.32.x, so that everything could be kept under control...

I am not experienced with the kernel, but I am willing to learn. A git tree would be superb to have (actually, that's my main interest).

Of course, if there is already something like this that I am looking for, I would be very happy to know.

Thanks for any comments.