Re: [Linux-fbdev-devel] The future of framebuffer

[Nick K. <nic...@ma...>]

Hello, Sven!
On Thu, 4 Oct 2001 18:07:51 +0200, you wrote:

> On Thu, Oct 04, 2001 at 07:58:51PM +0400, Nick Kurshev wrote:
> > Hello, Sven!
> > > Sure, but you aren't listening, you just plainly ignore all the non-i386
> > > hardware out there, as well as all the older vide ocards. And there are a lot
> > > of graphic cards that are supported but are not VESA 2.Ю or later compatible.
> > > 
> > > Also you plainly forget all those where VESA support is somewhat broken.
> > > 
> > > and if you use vesafb, you already have most of the fbdve infrastructure in
> > > anyway, so why not use decent drivers ?
> > > 
> > I'm sorry - I didn't know about non-x86 architectures.
> 
> Remember, fbdev was first developped by Geert on amiga hardware for
> linux/m68k, if i am not mistaken. These hardware don't have text consoles, and
> thus fbdev is a must have on those.
> 
> vesafb is simply a nice way to have X running on cards which are not supported
> by XFree86, as well as providing a penguin logo, and a place for some other
> kind of experimentation.
> 
Main plus of fbdev which I've found it's the fact that fbdev is running at CPL 0
(on x86 cpus) i.e. have kernel level of priviledges agains X11 which is running on
CPL - user level. Therefore it's best way to have top fast video drivers but not only
graphics console.
> > > You problem here is only with the fonts, why not use modular fonts that can be
> > > loaded, or even fonts provided by a userland app ?
> > > 
> > Unfortunately - linux documentations lacks (or hides) such information.
> > Could you send me URL, please?
> 
> There is the fbdev web site, i think, as well as the linux source code
> naturally, for something else, you would have to search ...
> 
From linux-kernel mailing list:
 On Sat, 25 Jul 1998, J. Patrick Avery Junior wrote:
 > does anyone know where I can find the program 'cpi2fnt' referenced in
 > linux/drivers/video/font_8x16.c?
 
 `cpi2fnt' is a very old AmigaOS program.
 
 Greetings,
 
 Geert

So it seems that it's still big problem ;)

> > > > > Finally, removing many dirvers from the kernel and having them as external
> > > > > projects is only asking for problems, incompatibilities and bugs. It is not a
> > > > > nice thing to do. 
> > > > > 
> > > > There may be incompatibility but only if linux internal interface is changed
> > > > but independed projects will not depend on it. Except case when major version of
> > > 
> > > Sure, but this has not been the case in the past, so ...
> > > 
> > > > linux will changed but this situation is similar to having different drivers
> > > > for Win95 and Win2000.
> > > 
> > > And is the main reason for all those crashes you get in windows : badly
> > > written or plain incompatible drivers.
> > > 
> > Windows (NT series) have only badly written kernel which crashes too frequently ;)
> 
> I heard that many of those crashes came from drivers from non reliable third
> parties.
> 
But I have a big practice in using of Windows OSes and know that blue screen of dead
can be caused by simplest DOS program and such crashes rather occur inside of kernel
than in drivers. At least after upgrading nvidia drivers from inet - all video problems
were disapeared but kernel's problem are still living.
> > > > In addition it will give possibility to update such drivers without updating
> > > > the kernel and vice versa.
> > > 
> > > I can already do that, Or do you think i need to rebuild the kernel each time
> > > i change a line in some fbdev driver code ?
> > > 
> > When I'd write a little Makefile for my tiny driver then I'd got such possibility too.
> > If you are developer therefore you have no such problems but many users use
> > only stable Linus kernels and they will never install even -pre.X kernel on their computers.
> > AFAIK - main problems of fbdev will be fixed only in 2.5 kernels (I hope not in 2.7;)
> > (I mean - at least correct unloading fbdev by 'rmmod fbdev' althrough it's meaningless on non-x86)
> > Thus mainstream of x86-users will wait until Linux-2.6 will be introduced.
> 
> Well, i hear it is well possible, the real problem is that you need another
> fbdev to put the console on in the meantime. if you have 2 fbdve, it can be
> done.
> 
> I think it really is a bug of the vgacon layer or whatever, ...
> 
Anyway - it would be better to move drivers like fbdev, audio and other out from kernel.
But kernel should have mechanism to handle the 3rd party drivers.
As for me - I already tired to reinstall alsa and lm_sensor drivers after each kernel updating.

> Friendly,
> 
> Sven Luther
> 


Best regards! Nick