I'm trying to use my old N770 (running OS2006) as a screen for a carputer, and want it to turn on when power is applied to the charger port.

I've so far, by hacking linuxrc in initfs, got it to show the main home screen (i.e. with menus and stuff) before the big black Charging screen appears. I haven't managed to get networking going in this state, so I can't ssh in and look at what processes might be causing the Charging screen (which I'd like to replace with my own code).

Any ideas as to how I could bypass this?

Well, unless the battery's dead, you could just leave it on... that doesn't answer your question, though.

Hrm, hacked an insmod g_ether and ifconfig into initfs/linuxrc and now I can ssh in while it's charging ... and systemui seems to be producing the charging screen. So all I need to do is work out how to configure it...

And ... sticking an "exit 0" at the start of /etc/init.d/osso-systemui* seems to have done the trick!

gah, spoke too soon, that makes the charging screen go away but touchscreen input seems to be disabled (!)

You're going to need to get somewhere earlier in the boot process, and find where it first checks the reason for booting, I think. This is out of the initfs, I believe, but before that. (systemui, BTW, is also responsible for such wonders as the power-key menu; altering its startup might have undesirable consequences even if the rest of the system was brought up already.)

I can get the keypad working with

echo 1 > /sys/devices/platform/omap-keypad/enable

... now all I need is the touchscreen. Any ideas?

Not right off, but I think that's the wrong approach; if you just set it early in the boot to consider it a "normal" boot, instead of a "charge screen" boot, you won't have to fix the half-dozen (or however many) differences. Unless you're actually wanting some different behavior than normal, it'll really be easier to fix it once, in one place...

I sort of do want different behaviour, though -- I'm going to use the N770 as a carputer screen, running a vnc client talking to a larger PC hiding somewhere over usbnet. So the current charging behaviour (boot up on charge port power, shut down on loss of charge port power) is something I do want -- if I can just get the touchscreen working and automatically start up a VNC client, I'm pretty much there.

And, replying to myself again, just adding an "exit 0" to the start of the script in /etc/init.d that starts up mce seems to be enough to keep the touchscreen working :-)