GTA04 Kernel¶

This page documents the various tried to get a working kernel for the GTA04 with ICS userspace.

Notes:

• The GTA04 is an AM37x OMAP board like the BeagleBoard XM. The other BeagleBoard models use another OMAP3 SoC.
• AM37x category on TI wiki

Resources:

• Neil Brown's gta04 kernel tree includes 3.2, 3.3, 3.4 and 3.5 kernels
• AOSP's common kernel tree includes 3.0 3.3 and 3.4 kernels

Rowboat kernel¶

The TI porting guide for AM37x devices advices to use the rowboat tree with the rowboat-ics.xml manifest.
The kernel in that tree is branch rowboat-ics-kernel-2.6.37 from the rowboat kernel.

Porting the GTA04 board and drivers to this kernel seems possible, however this is a very old kernel revision.
The gta04 kernel based on rowboat kernel is at: http://git.paulk.fr/gitweb/?p=replicant/kernel-gta04.git;a=shortlog;h=refs/heads/rowboat-gta04

Status matrix:

Component	Status
Board file	OK (boots normally)
RS232	OK
Modem	Missing
Power off/reboot	Reboot works, poweroff leaves led on, power button won't start it after poweroff
GPS	Missing
WiFi/Bluetooth	Missing
LCD	OK
Graphics (fb)	OK, fast
Touch screen	OK
Backlight	Missing
Sensors	Missing
Audio	Missing
Headset	Missing
USB	OK, automatic OTG host/device, issue at suspend
microSD	OK
Buttons	Missing
LEDs	Missing
Battery	Missing

Omapzoom kernel¶

Omapzoom (where TI pushes code for Android) has an omap3 kernel that should match ICS userspace.
However, when running on the GTA04, serious power management issues caused characters to be dropped on serial after not touching the phone for a couple of seconds as well as IRQ interrupts being dropped, which caused the touchscreen to not work properly. Suspend/resume and earlysuspend works perfectly though. Maybe this kernel wasn't designed for AM37x OMAP3 devices but another kind of OMAP3 SoCs: there is no support for Android Beagleboard.

AOSP's 3.4 common kernel merged with Neil Brown's 3.4 gta04 kernel¶

Merging AOSP's 3.4 common kernel on top of Neil Brown's 3.4 gta04 kernel and adding the Android options to the defconfig resulted in a non-working kernel where input events didn't seem to be reported correctly to userspace (even with an USB mouse, click events seemed dropped).

Kernels on Gitorious/Replicant:¶

The repository is here,

• the replicant-4.0+3.7+WIP branch contains the kernel 3.7 for the gta04(which comes from neil brown's git (git://neil.brown.name/gta04.git) probably at the 3.7-gta04 branch with adb forward-ported to it on top. The others android features comes from the mainline 3.7 kernel.
• the replicant-4.0+3.8+WIP branch contains the experimental/android-3.8 branch of the AOSP common kernel with on top, the result of the rebase of the mainline branch of neil brown's git on top of 3.7 (which was also pushed in neil-rebase-3.7 branch for historic purposes), which is forward ported to 3.8

Status matrix:¶

Component	Status
Board file	OK (boots normally)
RS232	OK
Modem	Untested, should work
Power off/reboot	Reboot works, poweroff crashes with adb
GPS	Untested, should work
WiFi/Bluetooth	Untested, should work
LCD	OK, looks strange after suspend
Graphics (fb)	OK, fast
Touch screen	OK
Backlight	Working
Sensors	Untested, should work
Audio	Untested, should work
Headset	Untested, probably needs to be adapted to android
USB	OK, adb works but doesn't shut down properly
microSD	OK
Buttons	works
LEDs	Untested, should work
Battery	Untested, should work
frequency scaling	not working in neil's kernel, waiting for a fix

h3. Issues

Both branches seem to make trebuchet freeze, on the system log there is:
I/WindowManager( 191): Input event dispatching timed out sending to Keyguard