Re: [Linux-fbdev-devel] Frame buffer drivers compiled as mo

[Petr V. <VAN...@vc...>]

On 21 May 01 at 23:09, Otto Wyss wrote:

> > Drivers do not read options from modules.conf, modprobe does. When built
> > into kernel, fbdev drivers support unified 'video=<fbdevname>:options'
> > kernel cmdline argument, but when they are built as modules, it differs
> > from driver to driver (f.e. matroxfb supports all these options,
> > instead of video=matrox:a:b you write 'insmod matroxfb_base a=b')
> > 
> And what if drivers gets loaded if the kernel module loader calls
> modprobe? 

modprobe reads modules.conf and creates correct insmod line.

> As far as I understand, in the atyfb, aty128fb the option processing are
> disabled through a compile time option (#ifndef MODULE).

someone have to change types for curblink, noaccel and default_vram to
int and then add

MODULE_PARM(curblink, "i"); MODULE_PARM(noaccel, "i") ... and so on.

If you compiled driver as module, then mode database is not available
(it is __init thing), so there is no way how to get non-default resolution.
But you can add

post-install atyfb fbset 1280x1024@100 -a

into modules.conf.

> > I do not understand. Of course that if you compiled these drivers as modules
> > then they are started after / is mounted r/w. What else do you expect
> > from modules? And if you are talking about fbdev drivers in kernel, then
> > 
> Why do they have to wait after / is mounted r/w? If a driver doesn't
> write to the drive there is no need. What's the difference between a
> linked and a modularized driver besides just store in different places.

/etc/modules is usually parsed after / remounted r/w. If you trigger
module load by accessing /dev/fb*, then it is different, of course.
Difference between built in and modularized driver is that builtin
driver can get options from kernel commandline and is initialized before
system comes up. Modularized drivers can be loaded only after / filesystem
was mounted (at least read-only), so couple of things have to happen
before. You should built-in all drivers for hardware your machine has into
kernel unless you are just developing that drivers. It saves you from
couple of troubles...
                                            Best regards,
                                                Petr Vandrovec
                                                van...@vc...