On Wed, 15 Jan 1997, Matthew N. Dodd wrote:

> I've got a SPARCstation 2 with a CG6 and a CG3 in it that I'm trying to
> get working in a multiheaded fashion.
> 
> I don't know of any reason why this shouldn't work, but so far I've not
> had much luck.  The OS finds both framebuffers but I'm only able to run X
> on the CG6.  (I'm using the right -dev or XDEVICES settings too.)
> 
> Does anyone have any ideas?


I have an IPC with the built-in BW2 and a CG3.  I've run X with monitors
plugged into both under NetBSD/sparc 1.1.  I had to hack on the bwtwo.c
device driver to get this to work.

Specifically, I had to modify bwtwoattach() for the case when the BW2 isn't
the console.  Apparently the boot PROM sets some hardware registers that
the bwtwo.c driver does not.  I made the bwtwoattach() set the 
sc->sc_reg->bw_xxx1[] and sc->sc_reg->bw_xxx0[] arrays to "magic" values.
I got the magic values through a laborious process of modifying the driver
to print out the sc->sc_reg->bw_xxx* arrays when it attached the device
at boot.  Then, I booted without the CG3, noting the output values.
Modified the driver code to set these magic values, put the CG3 board
back in, and booted with it.  This process took several tries.

I can email you the bwtwo.c source, but that won't help with a CG6.