Resurrecting uvesafb and turning it into a kms driver ?

David Herrmann dh.herrmann at
Tue Jan 21 03:57:43 PST 2014


On Tue, Jan 21, 2014 at 9:36 AM, Hans de Goede <hdegoede at> wrote:
> Hi,
> I've started a discussion on fedora-devel about what to do with old-style
> userspace mode setting
> drivers when the suid root bit is removed from the X server binary:
> I started this discussion there because to me the decision to actually
> remove the suid root bit,
> and the implications of this wrt supported devices, etc. is mostly a distro
> decision. I assume
> we as upstream will keep supporting the suid root + ums way of working for a
> long time yet.
> One interesting remark made in the discussion thread I linked to is to
> simply drop support for
> ums all together (in Fedora) and ship uvesafb ported to be a kms driver for
> cards which don't
> have kms support yet.
> I think this is an interesting approach, so this leads me to the question
> how crazy would it
> be / how crazy a person would it take to do this. Specifically the
> resurrecting uvesafb and
> turning it into a kms driver part ?
> And related to this, assuming it is considered doable by a sufficiently
> motivated person,
> would it be worthwhile ?

I wrote that like 1 year ago and have been resurrecting it the last
week. Unfortunately, I'm quite busy so will not get it ready before
FOSDEM, I think. Note that the branch is highly out of date, I changed
a lot in my local tree.

SimpleDRM is not exactly uvesafb, but it's a driver which would allow
an arbitrary backing framebuffer. It can already replace efifb, vesafb
and simplefb. Any other fbdev driver would just need a new backend
(like 200 lines of code).

Does that sound good? Or do you really need the uvesafb functionality.
I really dislike the user-space connection.. but if you want it, I
also have a bunch of patches here that allow user-space controlled
devices which I use for debugging. I can try to prep them for FOSDEM.


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