[PATCH v1 0/3] framebuffer rotation

[kbader94]

This patch series implements a framebuffer rotation configuration option which 
allows the user to specify a rotation translation to be applied to the video 
output from grub, such that user can programatically rotate the display. This 
enables grub to be used in nonstandard display mounting schemes such as 
portrait mode.

    Patch 1: dirty-2d - track and update 2d regions in the framebuffer. This 
simplifies the implementation of the framebuffer rotation.
    Patch 2: frambuffer rotation - numerous changes in the video_fb subsystem 
to enable specifying render_target rotation.
    Patch 3: enables setting the framebuffer rotation by setting 
GRUB_FB_ROTATION in /etc/default/grub. NOTE. rotation is passed on to linux 
unless GRUB_GFXPAYLOAD_LINUX = text

Status: Works as intended, however some optimizations(particularly in the 
blitting functions) have been left for future implementation.