mtrr setup memory type range registers for the vesafb framebuffer.
+vram:n remap 'n' MiB of video RAM. If 0 or not specified, remap memory
+ according to video mode. (2.5.66 patch/idea by Antonino Daplas
+ reversed to give override possibility (allocate more fb memory
+ than the kernel would) to 2.4 by tmb@iki.fi)
Have fun!