Re: [announce 7/7] fbsplash - documentation

Jon Smirl
2005-03-08T06:14:43Z

On Tue, 8 Mar 2005 04:18:07 +0100, Arnd Bergmann <arnd@arndb.de> wrote:
> On Dinsdag 08 März 2005 03:17, Michal Januszewski wrote:
>
> > +It's possible to set path to the splash helper by writing it to
> > +/proc/sys/kernel/fbsplash.
>
> It should probably just use its own hotplug agent instead of calling
> the helper directly.

Framebuffer is already generating hotplug add/remove messages.

HOTPLUG_TIME='Mon Feb 28 02:15:25 EST 2005'
PHYSDEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0
SUBSYSTEM=graphics
HOTPLUG_ARGS=
DEVPATH=/class/graphics/fb0
HOTPLUG_TYPE=graphics
ACTION=add
PHYSDEVDRIVER=radeonfb
DEBUG=yes
PHYSDEVBUS=pci
SEQNUM=537

This event can be caught in early userspace. The helper app will need
to live on initramfs/initrd and be small. Statically link it to klibc.

You can use the modular fb patch that has been recently posted (just
about to go in -mm) to make hotplug fbdev debugging much simpler.

Alternatively you might want to look at how request_firmware works.
You could easily load the picture as if it were firmware. I'm looking
at modifying request_firmware to be more general right now.

A direct call to call_usermodehelper() requires you to build a path
and app name into the driver.

--
Jon Smirl
jonsmirl@gmail.com