Status of the Ubuntu port to the AC100/Dynabook Tegra based netbook

This page collects information necessary to get a working Ubuntu port on the AC100 using only open source components and everything in the official archives (or temporarily in PPAs)

Hardware

The AC100 is an nVidia Tegra2 based device which has Android 2.1 as factory default. It has dual ARM Cortex-A9 cores at 1 GHz and nVidia GPU technology on its System On Chip. Some models come with 3G modems and the eMMC flash storage comes in various sizes.

Strengths

• Very slim and light
• Long battery life
• HDMI out

Weaknesses

• Slow eMMC storage (not an SSD)
• No VGA out (must use a displaylink device for most projectors)

Features known to work on Ubuntu: webcam, touchpad, 3G modem, WiFi, OpenGL ES (proprietary), indicator LEDs, card reader

Incomplete support: video acceleration, HDMI out, audio

TODO: more info? link?

Boot loader

The current first stage bootloader is Android Fastboot which uses the kernel and initramfs images found on partition 6 of the device. The partition can be written via the mini-USB port from another computer using the closed source nvflash utility from nvidia or opensource putusb, or updated from an already running system. The boot partition can be handled using the abootimg tool.

The ac100 PPA has a kernel that reads the (nvidia-proprietary format) main partition table, so kernel upgrades are possible. The flash-kernel package in the PPA takes care of this.

U-Boot

The default boot loader is inflexible, and there is interest in adding U-Boot as a second stage boot loader. There are Tegra based U-Boot using devices but there's no working AC100 image yet that can handle the eMMC or the screen to be actually useful for a wider audience.

Kernel

As of early August 2011 a 2.3.38-chromeos kernel fork is used in Ubuntu. It does not support suspend/resume and sound yet. Work is done to upstream AC100 support patches in 3.1 and 3.2 kernels so we can use mainline eventually.

Built kernels are in the ppa: https://launchpad.net/~ac100/+archive/ppa

Kernel tree is at https://gitorious.org/~marvin24/ac100/marvin24s-kernel

Graphics

Latest Linux4Tegra SDK from Nvidia is 12alpha1 for kernel 2.6.38.

WebGL

Chromium browser v 13 from the Oneiric Ocelot archive works with some WebGL demos if passed --use-gl=egl --ignore-gpu-blacklist at the command line.

http://www.khronos.org/webgl/wiki/Demo_Repository

GLES demos

The native visual ID for all EGL fbconfigs seems to be returned as 0

eglGetConfigAttrib(ed, &config, EGL_NATIVE_VISUAL_ID, &id); //id = 0

so most GLES apps will not work as there appears to be no visual with that ID.

Example of change needed in es2tri.c from the mesa-utils-extra package

- visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals); + visInfo = XGetVisualInfo(x_dpy, VisualNoMask, &visTemplate, &num_visuals);

Screen depth

In the Xorg config file, a depth should be set as 16 or else not even the limited support for GLES as seen above is available.

Section "Screen"

• Identifier "myscreen" Device "Tegra"

  DefaultDepth 16

EndSection

Installer

There is an installer using the 2.6.37 kernel which is known not to work on the 10Z model and others that use a SanDisk internal eMMC for storage.

http://people.canonical.com/~ogra/tegra/2.6.37/

A new installer based on the 2.6.38 kernel is in the works.

Contact

IRC: #ac100 on freenode

Mailing list archives: https://lists.launchpad.net/ac100/

Launchpad team: https://launchpad.net/~ac100

Misc links

ONLY PUT HERE LINKS THAT ARE STILL RELEVANT FOR PRESENT AND FUTURE DEVELOPMENT AND DO NOT LEAD TO UNNECESSARY WORK AND CONFUSION.