Group: Hardware/research/gpu/radeon

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Introduction

The Radeon GPUs have many freedom issues that are referenced on the table below.

Nonfree software Effects without the nonfree software or workarounds Workaround Workaround consequences Fix Existing projects that could be leveraged to fix the problem
Radeon firmwares/microcodes

The Radeon driver doesn't load and Linux falls back on another driver like VESA or efifb:

  • Native resolutions might be missing
  • No multi-display
Patch the radeon driver in linux-libre to enable it to load and work without the nonfree firwares

The radeon driver loads:

  • Native resolutions become available
  • Multi display is available
  • 3D acceleration is still missing
Write free replacement for the firmwares
  • The nouveau project generates free firwmare in the Linux driver. While it's not meant to support non-nvidia GPUs, it could be a good idea to use a similar software architecture.
AtomBIOS bytecode: This bytecode is part of the Video BIOS and is parsed and executed by the Linux driver
  • The radeon driver doesn't load
  • The boot software (BIOS, UEFI) may not be able to initialize the display. Untested.
? Replace the nonfree bytecode by a free one.
  • The RadeonHD driver did that, however it wasn't chosen as the main Radeon driver because it didn't match ATI's Interest.
  • Other? TODO: Look if the video BIOS replacements also deal with the AtomBIOS bytecode.
The Video BIOS Use Libreboot or Coreboot with SeaBIOS, put the Video BIOS in memory but don't execute it The display is initialized very late, when the Radeon driver loads, if the AtomBIOS tables are in the right memory area. Implement a free Video BIOS replacement either as standalone replacement or in Coreboot and Libreboot.
  • There is a free Video BIOS replacement in Coreboot for many Intel GPUs. While its meant to support Intel GPUs, it may be a good idea to leverage some of the code and architecture. It may also be a good idea to instead implement it as a standalone Video BIOS replacement, as standalone Radeon GPUs do exist, whereas standalone Intel GPU don't at the time of writing.
  • TODO: List Vide BIOS Replacement projects and their freedom issues (check if the compiler is free)

Hardware documentation

Firmware name Hardware name Function Replacement strategies
? CP: Command processor Probably fetch and decode the GPU commands like a CPU does for the commands.

How to help

Documenting all the freedom issues in depth and adding support for all the GPUs in linux-libre is a lot of work for one person.

Hopefully it can be broken in many small tasks, so it's easy to help by making a tiny part of the work.

Here are some relatively small tasks that could help:

  • Help completing the table in the linux-libre status section by helping to add information on the files/GPUs below:
    • ni_dpm.c
    • si_dpm.c
    • cik.c
    • radeon_uvd.c
    • radeon_vce.c
    • btc_dpm.c
    • ci_dpm.c
    • cik.c
    • cik_sdma.c
  • Help completing the table in the introduction section
  • Add support for a GPU you can test on. Reading the tutorials might give you an idea of how long it would take for you to do it, and how easy it is for you to do that.
    • There is a tutorial for Trisquel. It needs updating so you it would also be nice if you could add an updated version to this wiki page as well while you do that.
    • There is a tutorial for Parabola that will be added below shortly.
  • Migrate the information in ReverseEngineering#Desktops_and_laptops_GPUs here and make theses section point to this article for Radeon GPUs

Status in linux-libre

The radeon driver has code like that for many GPU families:

if (!rdev->me_fw) {
        r = r100_cp_init_microcode(rdev);
        if (r) {
                DRM_ERROR("Failed to load firmware!\n");
                return r;
        }
}

The result of that is that without the nonfree firmware, the radeon driver doesn't load.

Being able to use that driver, even if the 3D acceleration doesn't work without the nonfree firmware is very interesting:

  • it can enable native resolution
  • It supports multi-displays

If you have a radeon, ATI or AMD GPU from a family that isn't listed below and that works, please make sure that we get to know about it either by:

  • Adding it below
  • Sending a mail to the linux-libre mailing list and mentioning it
  • Contacting people on IRC that would do any of the above

It's also important to do the same for if you also have a GPU from a family that isn't listed below that doesn't work.

So far we didn't have access yet to GPUs from all families, so we weren't able to make them all work.

If you can manage to send a patch to linux-libre yourself it's even better as:

  • It enables you to learn many things along the way, including how to contribute to some free software projects if you don't already know how to do it.
  • We can spend time on other free software projects as well
family file commit introducing the driver .remove() code linux-libre status
r100 r100.c
70967ab9c0c9 radeon: Use request_firmware()
if (!rdev->me_fw) {
        r = r100_cp_init_microcode(rdev);
        if (r) {
                DRM_ERROR("Failed to load firmware!\n");
                return r;
        }
}
Patch not enabled
r600 (KMS) r600.c Always there:
3ce0a23d2d25 drm/radeon/kms: add r600 KMS support
if (!rdev->me_fw || !rdev->pfp_fw || !rdev->rlc_fw) {
        r = r600_init_microcode(rdev);
        if (r) {
                DRM_ERROR("Failed to load firmware!\n");
                return r;
        }
}
Working:
clean_sed '
/r = r600_init_microcode(rdev);/,/}/ s,return r;,/*(DEBLOBBED)*/,
' drivers/gpu/drm/radeon/r600.c 'enable blobless activation'
r600 (UMS) r600_cp.c
70967ab9c0c9 radeon: Use request_firmware()
UMS support has been removed in:
8333f607a631 drm/radeon: remove UMS support
Evergreen evergreen.c Working:
clean_sed '
/r = r600_init_microcode(rdev);/,/}/ s,return r;,/*(DEBLOBBED)*/,
' drivers/gpu/drm/radeon/evergreen.c 'enable blobless activation'
rv770 rv770.c Working:
clean_sed '
/r = r600_init_microcode(rdev);/,/}/ s,return r;,/*(DEBLOBBED)*/,
' drivers/gpu/drm/radeon/rv770.c 'enable blobless activation'
Northern Islands ni.c Maybe this commit or before (not clear):
0af62b016804 drm/radeon/kms: add ucode loader for NI
if (rdev->flags & RADEON_IS_IGP) {
        if (!rdev->me_fw || !rdev->pfp_fw || !rdev->rlc_fw) {
                r = ni_init_microcode(rdev);
                if (r) {
                        DRM_ERROR("Failed to load firmware!\n");
                        return r;
                }
        }
} else {
        if (!rdev->me_fw || !rdev->pfp_fw || !rdev->rlc_fw || !rdev->mc_fw) {
                r = ni_init_microcode(rdev);
                if (r) {
                        DRM_ERROR("Failed to load firmware!\n");
                        return r;
                }
        }
}
Working:
clean_sed '
/r = ni_init_microcode(rdev);/,/}/ s,return r;,/*(DEBLOBBED)*/,
' drivers/gpu/drm/radeon/ni.c 'enable blobless activation'
Southern Islands si.c
9b136d514e35 drm/radeon/kms: fill in startup/shutdown callbacks for SI
if (!rdev->me_fw || !rdev->pfp_fw || !rdev->ce_fw ||
    !rdev->rlc_fw || !rdev->mc_fw) {
        r = si_init_microcode(rdev);
        if (r) {
                DRM_ERROR("Failed to load firmware!\n");
                return r;
        }
}

And:

/* Don't start up if the MC ucode is missing.
 * The default clocks and voltages before the MC ucode
 * is loaded are not suffient for advanced operations.
 */
if (!rdev->mc_fw) {
        DRM_ERROR("radeon: MC ucode required for NI+.\n");
        return -EINVAL;
}
Working:

The patch has been merged in linux-libre:

How to patch and test linux-libre in Parabola

See the tutorial in the radeon/How to patch and test linux-libre in Parabola page.

How to patch and test linux-libre in Trisquel

There is a tutorial for Trisquel however It needs updating. So if you use it, it would also be nice if you could add an updated version here while you try the tutorial.

As it might be required to give permission to do so, Here is the permission:

As I (Denis 'GNUtoo' Carikli) wrote this tutorial, I agree to assign copyright for your contribution to the Free Software Foundation (Copyrights). I am also promising us that I wrote this myself.

Status in the Xorg radeon driver

family distribution and version information configuration files status comments
  • Northern Islands
  • Southern Islands
  • Parabola
  • extra/xorg-server 1.20.5-2
  • extra/xf86-video-ati 1:19.1.0-1
Stock Xorg configuration files:

/usr/share/X11/xorg.conf.d/10-radeon.conf:

Section "OutputClass"
	Identifier "Radeon"
	MatchDriver "radeon"
	Driver "radeon"
/usr/lib/Xorg: symbol lookup error: /usr/lib/xorg/modules/drivers/radeon_drv.so: undefined symbol: exaGetPixmapDriverPrivate
This is probably specific to that GPU family: The hardware may lack a 2D acceleration engine and EXA might fail because of that.
Modified Xorg configuration files:

/usr/share/X11/xorg.conf.d/10-radeon.conf:

Section "OutputClass"
	Identifier "Radeon"
	MatchDriver "radeon"
	Driver "modesetting"
	Option "AccelMethod" "none"
EndSection
Xorg works The modeseting driver is probably as good as the xf86-video-ati driver when 3D acceleration is not available

External links