Re: Display goes offline at install boot

Greg Troxel <[email protected]> Wed, 25 Oct 2023 11:55:41 -0400
Newsgroups gmane.os.netbsd.ports.i386
Message-ID <[email protected]>
Bradley Pearce <[email protected]> writes:

> I'm trying to install NetBSD on a 32-bit Intel based Mac Mini.  It
> starts booting into the OS and right after it outputs "kern info:
> [drm] applying backlight present quirk", the monitor looses connection
> to the computer.  The OS clearly continues booting as I can hear the
> CD drive working.  Once the screen is off, I can't get it to come back
> up.
>
> At the boot prompt, I've selected option 3 and tried all of the
> following without success.
> boot> userconf disable i915drmkms*
> boot> boot
> -and-
> boot> userconf disable radeon
> boot> boot
> -and-
> boot> userconf disable igmafb
> boot> boot
>
> It was all just a shot in the dark, but didn't effect anything.  Any ideas?
> According to the internet, specs of the system are 1.5Ghz Core Solo
> (T1200), graphics = Intel GMA 950 DVI output.

I would:

  video record the boot so you can see what was there in total just
  before boot

  disable all of those things, not just one at a time

  read the code around 'backlight present quirk' and see if that leads
  to any suggestions