User:GNUtoo/X60 GPU init

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Revision as of 22:38, 17 January 2015 by GNUtoo (talk | contribs)
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Native GPU init

With the native (intel) GPU initialisation, coreboot itself initialises the GPU.

Initialisation method Free software, based on Advantages Drawbacks
non-free VGA option rom No, extracted from the BIOS.
  • compatible with everything
  • works with the official coreboot.
  • non-free
  • even yabel cannot contain it
Linux kernel i915 driver Yes, in the linux kernel
  • works with the official coreboot.
  • The screen content is only visible after the i915, so you cannot see grub.
  • It worked with trisquel6 kernel, and had issues with some recent kernels.
    • TODO: investigate the memory_corruption_check kernel parameter.
Native GPU initialisation (by coreboot) Yes, based on a replay of the kernel initialisation
  • compatible payloads can use the screen.
  • not in the official coreboot yet.
  • only compatible payload will be able to use the screen, like:
    • libpayload based payloads
    • recent grub versions

Related historic git trees

I often contained work on the following topics:

  • Native GPU init for i945
  • The fallback mecanism
  • The removal of the microcode

So I often have cherry-picked patches from gerrit and have some updated copies of some of them. The microcode removal is probably not in gerrit because it won't be accepted as-is, instead the microcodes have to be moved/removed in a cleaner way for master