Intel GMA 500

The Intel Poulsbo Chipset, also known by its official names "GMA 500" and "Intel System Controller Hub US15W", is typically found on boards for the Atom Z processor series. It embeds a PowerVR SGX 535 graphics core developed by Imagination Technologies and then licensed by Intel. Its major advantages include the hardware decoding capability of up to 720p/1080i video content in various state-of-the-art codecs, e.g. H.264.

As the graphics hardware was not developed by Intel themselves, the standard Intel drivers do not work with this hardware. Furthermore, at least two different accelerated Linux drivers for this hardware exist, each of which have major problems. Alternatively, there is a generic framebuffer driver solution, but this is unaccelerated.

On this page you find comprehensive information about how to get the best out of your Poulsbo hardware using Arch Linux.

Drivers: Advantages and Disadvantages

Kernel's psb-gfx module

With kernel 2.6.39, a new psb_gfx module appeared in the kernel developed by Alan Cox to support Poulsbo hardware. Currently this is very rudimentary but the development is very active and this should get better and better with upcoming kernels.

Advantages

• Up to date kernel and Xorg
• 2D acceleration
• Nothing to do to make it work

Disadvantages

• Did not manage to get native resolution (e.g 1366x768)
• Buggy backlight control (Fixed in Linux 3.0.0)
• No 3D acceleration possible
• Poor performances (use mplayer with x11 or sdl so fullscreen video will be quite slow)

PSB/GMA500 Driver

Advantages

• Native resolution
• 2D acceleration
• Possible 3D acceleration with work and luck - Fedora, as well as Ubuntu, have this [1]
• Backlight control possible

Disadvantages

• Performance not on par with IEGD (Youtube videos play smoothly at 360p, perhaps 480p, but no higher)
• Not supported through official packages. Use of AUR required.
• Needs kernel <=2.6.37 and Xorg 1.9

PSB/GMA500 Driver with FBDEV

Advantages

• Up to date Xorg without hacking libdrm
• Native resolution
• 2D acceleration
• Backlight control possible

Disadvantages

• Needs kernel <=2.6.37
• Performance comparable to FBDEV solution
• Not supported through official packages. Use of AUR required.

IEGD Driver

Advantages

• X works
• Native resolution
• Basic OpenGl Capabilities
• 2D acceleration
• HD video playback without stuttering

Disadvantages As of August 12 2010:

• Artifacts in video playback
• Suspend states are broken
• Works only for kernel <= 2.6.31 & Xorg server <= 1.6
• Lengthy process to install
• Not supported through official packages.

FBDEV Driver

Advantages

• Combined with 915resolution-static and Uvesafb, allows native resolution
• Up to date kernel and Xorg
• No recompiling needed on kernel updates

Disadvantages

• Video playback may not be smooth
• Flash video playback, such as on YouTube, not smooth above 360p
• Full-screen Flash video playback useless
• No Xv video acceleration whatsoever

Installation and configuration procedure is is discussed later.

VESA Driver

Advantages

• Combined with 915resolution-static and Uvesafb, possibly allows native resolution (untested)
• Up to date kernel and Xorg
• No recompiling needed on kernel updates

Disadvantages

• Video playback may not be smooth
• Full-screen Flash video playback useless
• Slower than the FBDEV driver
• Not supported through official packages. Use of AUR required.

Do I Need To Downgrade?

As of November, 2011 you do not need to downgrade anything to use the psb-gfx, FBDEV, or VESA Xorg video drivers.

However, if you wish to experiment with the PSB or IEGD driver, you will need to downgrade your kernel and maybe xorg-server, along with several other packages.

Xorg-server 1.7 or higher (current Arch)

Kernel's psb-gfx module

If you have a kernel newer than 2.6.39, then it should work out of the box.

The module is psb_gfx:

$ modprobe -l | grep psb
kernel/drivers/staging/gma500/psb_gfx.ko.gz

And xorg should use fbdev by default. You can check it in /var/log/Xorg.0.log.

PSB/GMA500 Driver

You need kernel <=2.6.37 to use the PSB-Driver

Install from custom repository

Add the following repository to your /etc/pacman.conf

[poulsbo-old]
Server = http://kissmyarch.eu/gma500/poulsbo-old/

and install the psb driver with

# pacman -Syu xorg-x11-drv-psb

Build and Install from AUR (xorg 1.9)

Build and install the following packages in this exact order

1) psb-firmware
2) psb-kmod
3) libdrm-poulsbo
4) xpsb-glx
5) xorg-x11-drv-psb.

Configure xorg.conf

To tell Xorg to use this driver, change the Driver line in /etc/X11/xorg.conf to read as:

Driver "psb"

You can also try adding a couple options to try improving acceleration or stability:

with:

Option "ShadowFB" "true"

and possibly:

Option      "MigrationHeuristic" "greedy"

Cross fingers and restart X.

Hardware accelerated video playback

In order to have video acceleration, you must

• Install xorg-x11-drv-psb
• Install libva-freeworld from AUR or from above given repository
• Install mplayer-vaapi from [community]
• Run

mplayer -vo vaapi -va vaapi videofile

PSB/GMA500 Driver with FBDEV

The advantage of this solution is that you just add a kernel module but you do not need to bother about specific Xorg version or libdrm while keeping backlight control.

It makes it simpler to manage than the PSB/GMA500 Driver and FBDEV Driver solutions.

Build and Install from AUR (xorg 1.9)

Build and install the following packages in this exact order

1) psb-firmware
2) psb-kmod

You can either download these packages from the repository given above.

Install the fbdev Xorg driver

# pacman -S xf86-video-fbdev

Configure your system

Load the module at startup by adding "psb" to you MODULES in /etc/rc.conf. To avoid an unnecessary reboot, as root perform to get your module loaded:

# modprobe psb

To tell Xorg to use the framebuffer driver, change the Driver line in /etc/X11/xorg.conf to read as:

Driver "fbdev"

Restart X and you are done !

FBDEV Driver (xf86-video-fbdev)

Download v86d and xf86-video-fbdev:

pacman -S v86d xf86-video-fbdev

You will also need to install 915resolution-static from the AUR or the repository given above.

Create the file /etc/modprobe.d/uvesafb.conf, if it does not exist, and change it so the only non-comment line is this:

options uvesafb mode_option=1280x800-32 scroll=ywrap

Make sure you use the right resolution for your setup -- if you have a 1366x768 screen, for example, change the "mode_option=" number to "1366x768-32".

Edit /lib/initcpio/hooks/915resolution and make sure it has the right resolution for your setup -- the same resolution as specified in /etc/modprobe.d/uvesafb.conf.

Next, edit /etc/mkinitcpio.conf and add 915resolution and v86d to the "HOOKS", like this:

HOOKS="base udev 915resolution v86d ..."

Make sure you run mkinitcpio:

mkinitcpio -p linux

Edit /etc/X11/xorg.conf and change driver to fbdev:

Driver "fbdev"

See the Uvesafb article for more information.

VESA Driver

Download xf86-video-vesa and install.

# pacman -S xf86-video-vesa

Then edit /etc/X11/xorg.conf to use it.

Driver "vesa"

Xorg-server 1.6

Please note that Kernel 2.6.31 and Xorg server 1.6 are no longer supported by the Arch Linux team.

Installing Xorg-server 1.6

Add to your /etc/pacman.conf the following custom repository and make sure it is higher than the others.

[xorg16]
Server = http://catalyst.apocalypsus.net/repo/xorg16/i686/

Then uninstall old packages if any, and install xorg

# pacman -R xorg-server xf86-input-evdev xf86-input-mouse xf86-input-synaptics xf86-input-keyboard 
            xf86-video-vesa xf86-video-fbdev
# pacman -S xf86-evdev xorg-server xf86-input-keyboard xf86-input-mouse xf86-input-synaptics 
            xf86-video-vesa openssl-compatibility

An older version of libssl is required. This can be fulfilled using the openssl-compatibility package from the AUR.

mkdir openssl-compatibility
cd openssl-compatibility
wget http://aur.archlinux.org/packages/openssl-compatibility/PKGBUILD
makepkg -s
# pacman -U openssl-compatibility*.pkg.tar.xz

Once this is done, you may reboot the computer. Alternatively, kill all instances of Xorg and restart.

The Xorg 1.6 server should start without issue.

FBDEV Driver using xorg-server-1.6.3.901

The xf86-video-fbdev driver is not currently in the Chakra Project's repositories. Download and install from here

$ wget http://dl.dropbox.com/u/6228981/poulsbo/i686/fbdev/xf86-video-fbdev-0.4.1-1-i686.pkg.tar.gz
# pacman -U xf86-video-fbdev-0.4.1-1-i686.pkg.tar.gz

Installing IEGD-enabled kernel

This process is still under development. Some info may be found here.

Installing IEGD binary drivers

tbd

Troubleshooting Xorg 1.6

Driver cannot be found

If X complains that the driver cannot be found, you may have the FBDEV driver specified in xorg.conf file, but the FBDEV driver is not installed as described in above. Revert back to "vesa" by finding the line with the video driver - fbdev - and alter it,

Driver "fbdev"

to

Driver "vesa"

Then make sure to follow the steps in the aforementioned section on installing FBDEV.

Taking Advantage of non-FBDEV/VESA Driver

Set backlight brightness

This has only been tested with the PSB driver

This is pertinent to machines with built-in LCD screens, not to devices such as the Fit-PC

With a driver installed and loaded (via modprobe or at boot), all that is needed to set the brightness is sending a number (0-100) to

/sys/class/backlight/psblvds/brightness

This obviously requires sysfs to be enabled in the kernel, as it is in the Arch Linux kernel.

An example: to set display to minimal brightness, issue this command as root:

echo 0 > /sys/class/backlight/psblvds/brightness

Or, for full luminosity:

echo 100 > /sys/class/backlight/psblvds/brightness

A very short script is available to do this with less typing written by mulenmar.

#! /bin/sh
sudo sh -c "echo $1 > /sys/class/backlight/psblvds/brightness"

Simply save it as brightness.sh, and give it executable permissions. Then you can use it like so:

Set brightness to minimum:

   ./brightness.sh 0

Set brightness to half:

   ./brightness.sh 50

Sudo may obviously ask for your password, so you have to be in the sudoers file.

See also

• An experience about configuring Poulsbo (spanish)