Don't understand handbook on drm-kmod video driver

zeugme

New Member


Messages: 13

Hi,

I don't understand this handbook doc chapter
I'm new to FreeBSD, it might be obvious but the doc explain to only change/write a file pointing to the driver under xorg.conf.d.
  1. driver is supposed to be detected, right ? So why is there nothing in this folder ? Where is the auto-detection result stored ?
  2. I don't see any pkg install step in the doc, so I'm puzzled, the driver must come from somewhere, isn't it ?
This an old Macbook pro. There is a Radeon X1600 in it. It is supported according to this hardware doc
I was not able to launch 64 bits version of FreeBSD but the i386 worked. The proc is a true 64 bits one. Puzzled again :)
I found a thread with that and as a conclusion, the guy was using i386. UEFI is apparently 32 bits explaining why 64 bits DVD cannot boot.
Anyway, i386 worked and it is fine, I don't need 64 bits on this machine.

Then, it goes all right until I added Gnome 3 and follow documented steps. When it boot, it loop on bizarre scrambled graphical screen.
I can see the text login, it should load graphical login screen and failed with that scrambled screen and loop again.
No way to switch to a text console tty with ctrl-alt Fx

I had to boot the install CD again and prevent gdm to be enable in rc.conf.
By the way, is there a way to boot with a console on the boot menu ? It was quite long to go via the install DVD to get a console.
From there, I was able to boot back to HDD without Gnome and I didn't see error message in dmesg or in the log but I guess I had look to the latest one which was fine.

So I thought the driver might be the problem because of the scrambled graphics, the loop and because none look configured in that xorg.conf.d folder.

Nothing special mentioned here for this model and all models are far more recent than mine (2007)

Any idea ?

Footnote: why fighting ? Why not just install a Manjaro ? Yeah ... I know I'm crazy, but I'm trying to have only one distrib to run them all and I decided to learn FreeBSD :)
 

Wozzeck.Live

Member

Reaction score: 131
Messages: 79

In full drm kmod (graphics/drm-kmod), there is no xorg driver. The Video card is fully driven by the Kernel Module

In fact, be aware that since very last developments of Xorg, in most of case, xorg.conf is now D E P R E C A T E D.
Xorg can run WITHOUT any xorg.conf.

Xorg.conf is still required if you want to customize other devices, other sections. In such case, if you use full drm kmod, and you still have xorg.conf, YOU MUST DEACTIVATE ALL VIDEO SECTION IN XORG.CONF and so you should also deinstall any Xorg x11-drivers/xf86-video-xxx driver.

Please read and re-read the handbook. Full DRM-KMOD is only recommended for recent hardwares.
If you run very old hardware, you must still run DRM LEGACY KMOD, because you will encounter unstability issues. 3D acceleration will not work

Full DRM-KMOD is in fact a family of driver imported recently from Linux for Intel and AMD cards.
For nvidia, regarding FreeBSD (I can't certify for Linux), it is not handled by this common DRM-KMOD module.
For nvidia you must compile the proprietary driver which will generate its own kernel module, along with a Xorg driver.

In Legacy Kmod (graphics/legacy-kmod) the Kernel Module has a limited effect. This is a pure FreeBSD mode, not Linux.
In fact it just handles the new VT console to take benefit of high resolution... still for Intel and AMD/ATI cards only.

So Xorg needs a XF86 video family driver found in :

x11-drivers/xf86-video-xxx

In such case, YES xorg.conf will have a video section referring to the xf86 Xorg driver (intel, nvidia, ati, amd...)
drm-kmod IS NOT a xf86 video driver, this is an alternate driver this is the reason why there is no reason for xorg to refer to.
KMOD stands for 'kernel' module, so it supersedes transparently, intercepts and processes any access to the video card... so xorg doesn't need any driver...

Still today, even with recent hardware, so not only speaking of very old video cards, user still has the option to use or not the DRM-KMOD if he is not satisfied.
So he can revert to the legacy kmod (wich drives the VT console only), and can choose to handle real graphics operations with the specific xorg xf86 video driver
 
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zeugme

New Member


Messages: 13

Thanks a lot, I got the point.
No kmod drivers for this machine: too old!
I'll have to activate a radeon amd driver drm legacy kmod.

It will not prevent me for going forward, but is there a easy way to reach a console without having to use install DVD?
 

grahamperrin

Son of Beastie

Reaction score: 1,043
Messages: 3,502

… I haven't understood properly about how the graphics stack …

For a moment, imagine FreeBSD with graphics during the years before it became possible to use the port of the Direct Rendering Manager (DRM) subsystem of Linux.

It remains possible to have graphics without DRM. Some things will not work, but it's possible.

<https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=259410#c3> might help. Highlights:

1636862180976.png


X Window System

<https://en.wikipedia.org/wiki/X_Window_System> gives context to X11, X, X.Org and XFree86.

Tags: x11 | x.org | xorg | xf86 et cetera.

Closed: What is the future of X / X11? | The FreeBSD Forums

Last week's announcement of xorg-server 21.1.0 has an x.org tag.

Wayland (alternative to X.Org) and related technologies

Last week:

The "X.Org" forum has been renamed to "Display Servers"; the tagline has been updated to "X.Org and Wayland on FreeBSD; installation & configuration.

There's insufficient use of tags, so unfortunately: at a glance, it's a mash.

Tags: sway, wayland, xwayland et cetera.

<https://en.wikipedia.org/wiki/Wayland_(display_server_protocol)>

… XWayland is an X Server running as a Wayland client …
 
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