For the Netwinders (which uses the ARM SA110 RISC chip - a lovely British processor), there are two versions of the Cyber2000 framebuffer driver - one for 2.0.x kernels and one for 2.2.x kernels. It is quite straightforward to enable and use this driver on both kernels, however, the older version is hardcoded for depth and resolution (blech), but the good news is that the newer version in the 2.2.x kernels is much more flexible, but currently in a state of flux as it is still in development. To get this up and running, your best bet is to read the documentation that comes with the ARM port of the kernel sources.
The Netwinders uses a VGA compatible chipset, but unfortunately noone has ported vgafb to it yet. That might happen if someone has some time on their hands. [I would do it if someone would give me a NetWinder to play with]
Acorns have always had framebuffer support since the Linux 1.9.x days. However the Acornfb driver in 2.2.x is totally new since the generic framebuffer interface changed during the development of 2.1.x kernels (which, of course, became 2.2.x). As previously, it is a simple matter to activate the driver and set depths and resolutions.