85 lines
3.5 KiB
Plaintext
85 lines
3.5 KiB
Plaintext
|
Short summary about selecting a glx implementation
|
||
|
|
==================================================
|
||
|
|
|
||
|
|
To switch between the current and legacy NVIDIA drivers, use
|
||
|
|
|
||
|
|
update-glx --config nvidia
|
||
|
|
|
||
|
|
To switch between the GLX implementation from MESA/glvnd and NVIDIA
|
||
|
|
use the command
|
||
|
|
|
||
|
|
update-glx --config glx
|
||
|
|
|
||
|
|
This will also trigger an update of the initrd with a possibly changed
|
||
|
|
kernel module blacklist.
|
||
|
|
|
||
|
|
|
||
|
|
Detailed description of the diversions/alternatives for libGL.so.1 etc.
|
||
|
|
=======================================================================
|
||
|
|
|
||
|
|
NVIDIA provides accelerated OpenGL libraries libGL.so.* which are shipped
|
||
|
|
in the libgl1-nvidia-glx (or a corresponding libgl1-nvidia-legacy*-glx)
|
||
|
|
package. Furthermore NVIDIA maintains several legacy driver releases that
|
||
|
|
support older GPUs and ship files with the same names (but of course they
|
||
|
|
may not be mixed between different versions).
|
||
|
|
As these libraries and modules "replace" system libraries (libGL.so* from
|
||
|
|
MESA) and Xorg modules, care has to be taken to allow clean upgrades of
|
||
|
|
both the drivers and the system libraries.
|
||
|
|
|
||
|
|
Several additional requests have risen over time, e.g. from live systems:
|
||
|
|
* allow parallel installation of several drivers (even from different
|
||
|
|
vendors)
|
||
|
|
* allow driver selection at runtime
|
||
|
|
* allow switching back to the free Xorg/MESA implementation without having
|
||
|
|
to uninstall the accelerated driver and libraries
|
||
|
|
|
||
|
|
The vendor replacement libraries are only meant to be used as a complete
|
||
|
|
set as partial usage usually lead to hard to detect errors. So we only
|
||
|
|
support switching to a vendor implementation completely or using it not at
|
||
|
|
all.
|
||
|
|
|
||
|
|
Therefore we have chosen the following approach using diversions and
|
||
|
|
alternatives.
|
||
|
|
|
||
|
|
The system libraries are being diverted (to /usr/lib/mesa-diverted), so they
|
||
|
|
are moved out of the way of possible replacements and further updates to
|
||
|
|
them will happen at the diversion location. This is implemented in the
|
||
|
|
package glx-diversions which is a general solution to be used by all vendor
|
||
|
|
implementations.
|
||
|
|
All vendor implementations install their files in a private library directory
|
||
|
|
so there are no file conflicts happening. Then they register an alternative
|
||
|
|
'glx' which allows one to select the implementation. In case it is enabled,
|
||
|
|
all libraries (and other files) belonging to the implementation will be enabled
|
||
|
|
via slave alternatives, i.e. appropriate symlinks will be put into the system
|
||
|
|
locations. Triggers are being used to detect the installation or removal of
|
||
|
|
any file belonging to the slave set of an alternative and to update the
|
||
|
|
alternative accordingly.
|
||
|
|
|
||
|
|
User configuration can be done with the command
|
||
|
|
|
||
|
|
update-glx --config glx
|
||
|
|
|
||
|
|
which allows one to select a glx provider from mesa, nvidia.
|
||
|
|
(Available choices depend on the installed drivers.)
|
||
|
|
|
||
|
|
For NVIDIA, there is a second alternative that allows one to switch between
|
||
|
|
the current driver version and eventually installed legacy ones:
|
||
|
|
|
||
|
|
update-glx --config nvidia
|
||
|
|
|
||
|
|
|
||
|
|
libGL.so
|
||
|
|
========
|
||
|
|
|
||
|
|
The libGL.so link is managed by a dpkg trigger as an alternative, too.
|
||
|
|
But there are no alternative solutions available besides the diverted link
|
||
|
|
from the libgl1-mesa-dev package (if this package is installed), so this
|
||
|
|
cannot be reconfigured. The intention behind this is to always link an
|
||
|
|
application at compile time to the MESA implementation of libGL.so.1 in
|
||
|
|
order to produce portable binaries, but to use the accelerated libGL.so.1
|
||
|
|
when the application is being executed.
|
||
|
|
|
||
|
|
|
||
|
|
-- Andreas Beckmann <debian@abeckmann.de> Wed, 22 Jun 2011 12:44:11 +0200
|
||
|
|
|