[Linux-fbdev-devel] mmap()ing of FB memory area

[Romain D. <do...@ir...>]

Hello,
 
What happens exactly when an app mmap() a /dev/fb* ?

If the framebuffer is one bunch of linear memory,
you obviously get access to that, starting from
the first byte.

But what if a framebuffer use 2 discontinuous memory area,
say one for the main framebuffer, one for offscreen stuff
like overlay buffer, Z-buffer, texture... how can an app
access that ?

Also, when returning the pointer to an offscreen memory
buffer, is it better to give the physical address,
or an offset from the base address of the FB ?

TIA

-- 
DOLBEAU Romain               | l'histoire est entierement vraie, puisque
ENS Cachan / Ker Lann        |     je l'ai imaginee d'un bout a l'autre
do...@ir...             |           -- Boris Vian