AC100
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)
Contents
Installer
Prerequisites
Required for installation
- Mini-usb cable
- Host computer with linux (virtual or physical)
- Usb-stick or sd-card (min. 1GB)
- About 1-2h of your life (depending on the download-time)
Files to download
For the installation, you will need to download these things:
Oneiric Installer
There are two AC100 related files in the oneiric release directory:
Get them both and make sure that the md5sum corresponds after the download.
nvflash
The bootimage needs to be flashed via a mini-USB and using the nvflash tool.
This image when booted will set up the internal storage using a tarball provided on a USB stick or SD card.
The link contains instructions on how to easily install nvflash to your current debian-based linux-distro.
Installation
The installation is done in two phases:
Flashing the bootimage
- Make sure the battery is full on the AC100, or that the charger is connected.
- Shut down the AC100.
- Connect the mini-usb from the AC100 to your host computer.
- Put netbook in recovery mode by booting with ctrl and esc buttons held down. The screen stays off while the power led lights up.
- On your host computer, open a terminal and run:
nvflash --bl /usr/lib/nvflash/fastboot.bin --download 6 /path/to/ubuntu-11.10-beta2-preinstalled-desktop-armel+ac100.bootimg
NOTE: the path and name of fastboot.bin might vary, the guide uses version from http://share.grandou.net - Once nvflash is finished and prints out a message stating success, turn off the AC100 by pressing on the power button for several seconds.
Installing the preinstalled rootfs
Copy ubuntu-11.10-beta2-preinstalled-desktop-armel+ac100.tar.gz to a USB stick as a regular file on the first partition.
NOTE: DO NOT UNPACK OR DD THE TARBALL, JUST COPY! Make sure the md5sum is alright after copying to the media.- Reboot with the USB stick inserted and follow the simple instructions. Overall it does one reboot and in total can take about 20-30 minutes.
- Updating after installing is always a good idea, so after the install, start update-manager (or use apt).
Notes on installation
- Oneiric is still in beta, and random errors might (read: probably will) occur.
- If the touchpad comes unresponsive during latter part of the install, plug in a usb-mouse (this is a known bug in the kernel that is already fixed in the latest update).
A Note About Fragmentation
The effort the bring hardware support has always been fragmented. We are thankful for phh who did the initial bringup of a working linux kernel on the ac100 and made Linux4Tegra work on the older root filesystems ogra who built all Ubuntu root filesystems and the official oneiric images, marvin24 who has put effort in porting the Chrome OS kernel to the AC100, and the many others who were involved.
The downside of this fragmentation is that documentation is fragmented too. The goal of this wiki is to provide good quality information for the latest and most promising effort.
Wiki maintainers: don't reference the old "wetpaint" wiki. It is virtually unmaintained and will cause confusion. Information about the inner workings of the device and drivers must go here: http://ac100.grandou.net/
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 (SoC). 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, audio through headphones, suspend/resume, HDMI out (with the proprietary nvidia drivers)
Incomplete support: video acceleration, audio through speakers.
For details and a list of models, see http://ac100.grandou.net/models
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 (note that all packages from the PPA are integrated in the oneiric images linked above, in oneiric the PPA will only be used for post-release updates of single packages).
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 September 2011 a 2.6.38-chromeos kernel fork is used in Ubuntu and included in the Oneiric archives. It supports suspend/resume and sound from the headphones is working, speakers do not yet.
Work is done to upstream AC100 support patches in 3.x kernels so we can use mainline eventually.
The kernel tree the Ubuntu package is based on is at https://gitorious.org/~marvin24/ac100/marvin24s-kernel
zram compressed swap
This is included in the installation by default, only use the hack below if you did not use the Ubuntu installer
Since the AC100 only have 512Mb of RAM some applications will complain when the RAM gets full. ZRAM are a compressed ramdisk that can be enabled when using the latest Linux kernels. The ZRAM ramdisk can be used as a compressed swap device thus makes it possible to fit more applications into the AC100 RAM! ZRAM are quicker to use than to enable a swap device on flash.
The file zramswap.conf can be placed in /etc/init/ and will make Upstart configure and enable zram swap on bootup.
Adobe Flash
Dropping this library into ~/.mozilla/plugins allows flash playback. It warns though that it is out of date. http://kotelett.no/ac100/phh/Android2.2/libflashplayer.so
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. This is bug acknowledged by NVidia.
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 and eglut_x11.c from the mesa-utils-extra package
- visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals); + visInfo = XGetVisualInfo(x_dpy, VisualNoMask, &visTemplate, &num_visuals);
Some vertex and fragment shaders may show compile errors with the L4T driver. Mercifully, the error messages are usually informative enough to help fix the problem.
Example of change needed in es2gears.c from the mesa-utils-extra package
static const char fragment_shader[] =
+ "#ifdef GL_ES\n"
+ "precision mediump float\n;"
+ "#endif\n"
"varying vec4 Color;\n"
It is vital that none of the Mesa library equivalents of libGLESv2.so, libGLESv1_CM.so or libEGL.so are loaded by your target application at runtime. Doing this will make the application fail around the context creation step.
A good way to check is to run:
ldd ./name_of_gles_app | grep GL
All entries on the list should point to files in /usr/lib/nvidia-tegra.
Screen depth
By default, the L4T driver provides a 32-bit screen depth, which should be fully compatible with GLES.
It may be possible to improve performance by setting a depth of 16-bit in /etc/X11/xorg.conf
Section "Screen"
Identifier "<myscreen>"
Device "Tegra"
DefaultDepth 16
EndSection
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. In particular, try to avoid the wetpaint wiki.
Detailed info, useful for developers and power users: http://ac100.grandou.net/
IRC-logs for #ac100 @ irc.freenode.net can be found here: http://ac100.tunk.org/logs/