On 2020-08-11 10:18, karu.pruun wrote:
Hello
Is it possible right now to end up in a pre-DRM situation by default ?
IIRC kern.kms_console now defaults to 1 (don't know since when it does).
The terminology here is a little confusing. I used pre-drm to mean
"until a drm driver (i915 or radeon) is loaded". Let me try to clarify
booting.
The first screen with the boot menu is displayed by the loader. The
kernel modules to load by the loader are given in
/boot/loader.conf
However, the official advice is that the loader load the absolute
required minimum of kernel modules. For instance, my loader.conf has
no modules. This is because memory is tight at that early stage. If
you include, e.g. a drm driver, i915 or radeon, then the kernel will
most likely crash at boot.
The official advice is to load modules later by placing them in
/etc/rc.conf, for instance,
i915_load="YES"
I have all the required wlan, drm etc there. And you can also load the
drm modules manually on console using 'kldload i915'.
This means that, for instance, if I choose to load the drm driver
manually then I'm in the pre-drm stage until I will have kldloaded it,
say, on console, manually. The copyright note (the "Regents" screen
you mention), this is the kernel starting to load. This is pre-drm,
there is no drm driver anywhere. This is either VGA or the UEFI
display. The terminology "kms_columns" is misleading; that variable is
read by the system to try to figure out column x row configuration,
but there is no drm driver anywhere. That same "kms_columns" is also
read later by the drm driver to set the column x row configuration.
So long story short: it is all pre-drm until the drm driver is
literally kldloaded.
The screen change you see when going from loader to kernel loading
(the copyright, "Regents" note), there is no resolution change. The
resolution is the same as on the loader screen, it has been set by
UEFI. What you notice though is the change of font size. Between these
two screens, the system has done the calculation described in the
previous email, set the new column x row configuration, which is
larger than what you have in the UEFI screen; but there is no change
in resolution. Or perhaps there is slight change since it tries to
allocate a buffer that covers most of the screen.
I may have missed details, maybe someone can clarify more.
Cheers
Peeter
Things like this ought to be be added somewhere in the dragonfly wiki.
