Xvfb questions

[antst]

Hi!

I have few questions about Xvfb.

1) Does Xvfb support 1-bit depth? I tried, but in my case Xvfb starts
only with 8/15/16/23 bpp depth. And in all manual it is written that it
can support any depth.

Xvfb :3 -ac -screen 0 160x43x8 -shmem -dpi 43
starts normaly

Xvfb :3 -ac -screen 0 160x43x1 -shmem -dpi 43
complains
Fatal server error:
Couldn't add screen 0

2) What is the best way to control that framebuffer in shmem is
changed/repainted? I thougt "shmid_ds" returned by "shmctl" will
contains changed ctime, but it doesn't.

I'm trying to implement some kind of "driver" for new keyboards with LCD
screen in a style, where Xvfb draw framebuffer in shmem and driver copy
it into device. Not elegant probably, but very simple, 20 minutes and
prototype already is working :)

Anton.