Re: [gentoo-dev] maintainer-wanted: x11-drivers/nvidia-drivers

[Alexandre Rostovtsev <tetromino@gentoo.org>]

On Mon, 2013-03-04 at 11:28 -0500, Walter Dnes wrote:
> On Sun, Mar 03, 2013 at 10:48:07PM -0500, Rick "Zero_Chaos" Farina wrote
> 
> > I am sorry that this package has been such a headache for you,
> > unfortunately binary drivers (especially) are often like that. Thanks
> > for all your hard work keeping this usable.
> 
>   I'm not a C programmer, let alone a developer, so this may be a stupid
> question, but here goes... has anyone ever tried doing a HAL (Hardware
> Abstraction Layer) to present a reasonably stable interface to binary
> video drivers?  Think of it as a shim translating a "pseudo-API" into
> "the real API" that the kernel exposes directly.  Surely, we can do
> better than VESA.  Give drivers 2 options...
> 1) direct kernel access like now
> 2) access via the HAL/shim

For video drivers, there are only a few things that can be abstracted
away, e.g. hardware access synchronization, DMA, power management, a
memory manager for GPUs without dedicated video memory. And the kernel
already does have an API for this, called DRM (direct rendering
manager); see https://www.kernel.org/doc/htmldocs/drm.html

However, nvidia-drivers does not use this API, probably because they
want to share code between their Linux and Windows drivers, and the
Linux kernel's DRM API is too different from what Windows does. In
addition, there might be licensing issues: I once read an argument that
if a proprietary kernel module is too closely integrated with features
that exists only in the Linux kernel and that cannot be applicable to
other operating systems, the module might legally become a derived work
of the Linux kernel, and so would need to be open-sourced under the GPL.