Vesafb & two Linux framebuffers

Ken Loyd <[email protected]> Sun, 3 May 2009 16:38:26 -0700
Newsgroups gmane.linux.fbdev.user
Message-ID <[email protected]>
I hope this is the right place to ask, and any information available  
would be much appreciated!

My question is whether vesafb will detect and automatically create / 
dev/fb's for _both_ video out options if two are available?

My setup (for development purposes only) is a Dell Mini 10 which has  
the Poulsbo chipset (GMA500) which is currently in native driver  
purgatory. However, for my application I won't be running X or need  
any 3D acceleration or anything like that. I just need framebuffer  
consoles, and so the vesafb driver works just fine for my needs.

But, the GMA500/Poulsbo has two video connections. On the Mini 10, one  
is the built in display which presumably uses the LVDS of the GMA500  
and the other is an HDMI port which would be the SDVO.

On boot, vesafb creates the first framebuffer dev/fb0 no problem on  
the internal screen. Its obviously not that fast, but all I need to do  
is 'cat' some bitmaps to the screen so speed is a non-issue in my case.

But no matter what I do I can't seem to create a (functioning) /dev/ 
fb1 for the external video. I don't need spanning or mirroring or  
anything, just two independent (graphic) framebuffers to which I can  
'cat' bitmaps.

The Dell Mini 10 is just a temporary development platform for me. I am  
building an industrial machine which will have the Atom Z5xx-series &  
Poulsbo chipset as its base. (I'll be using the 'Robin' computer-on- 
module from Toradex.) The Dell Mini 10 has the same hardware chipset,  
so for its price, it makes a pretty decent starting point for  
development.

Thanks for any information you can provide!

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