Trying to multiboot with FreeBSD

karu.pruun karu.pruun at
Fri Jun 30 02:33:03 PDT 2017

On Thu, Jun 29, 2017 at 11:09 PM, Bryan C. Everly
<bryan at> wrote:
>> Hmm, this does not look good---I'm not a specialist but I don't
>> understand how you can see anything at all, the framebuffer address
>> and size are nonexistent. This is where it seems to break down.
>> When you give 'gop list', do you see any other modes? Can you change
>> to any other mode (sth like 'mode X' with X the mode number might
>> work?) and try boot?
>> Do you see the same numbers in FreeBSD and OpenBSD? If yes then we'd
>> need to investigate how Free/OpenBSD fix this.
>> If you can connect your machine to a wired network you can ssh into
>> the machine. You'd need to configure you NIC in /etc/rc.conf (same as
>> in FreeBSD) and note that by default DragonFly ssh configuration does
>> not allow passwds; you need either keys or then change the
>> configuration to allow passwds.
>> Peeter
>> --
> Peeter,
> When I do a "gop list", I get:
> mode 0: 1024x768x32, stride=1024
> mode 1: 640x480x32, stride=640
> mode 2: 800x600x32, stride=800
> mode 3: 1366x768x32, stride=1376
> So first off, that's weird that whatever "stride" is lines up 100% to
> the horizontal resolution in modes 0,1 and 2 but not mode 3 (which
> appears to be the default).
> Is there a way to change the default mode by putting something in
> loader.conf do you know?

Please try this: check that you are in the video group. If not, add
yourself in the video group in /etc/group, and then ensure that


is in /etc/rc.conf. Then boot again.

When this fails, back to modes at loader prompt. First we'd need to
figure out if there's a mode that works. At the loader prompt, try set
a mode that is not 3, I believe giving just 'mode 0' for instance to
get 1024x768. Can you then check with 'gop get' what are the values
address and size, if there's a mode where they are not zero. If yes,
then give 'boot'.

Also: when i915 loads, it should probe your screen and allocate a new
framebuffer with a suitable resolution; or 1024x768 if it fails to
find a resolution. If this is correct, then I'm not sure why putting
'i915_load="YES"' in /etc/rc.conf still resulted in corrupt screen. If
you can ssh into the machine you can see the debug msgs from i915
doing this:

% sudo kldload drm
% sudo sysctl hw.dri.debug=0x777
% sudo kldload i915

You'll get a lot of debug output in /var/log/messages, but grep for
the lines containing 'intelfb_create'; it should look like this:

[drm:pid1334:intelfb_create] no BIOS fb, allocating a new one
[drm:pid1334:intelfb_create] allocated 1680x1050 fb: 0x00047000, bo
kernel: kms console: xpixels 1680 ypixels 1050



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