On 08/14/2018 07:44 AM, Peter Maydell wrote: > The raspi framebuffir in bcm2835_fb supports the definition
framebuffer. > of a virtual "viewport", which is smaller than the full > physical framebuffer size and at an adjustable offset within > it. Only the viewport area is sent to the screen. This allows > the guest to do things like double buffering, or scrolling > by adjusting the viewport origin. Currently QEMU doesn't > implement this at all. > > Add support for this feature: > * the property mailbox code needs to distinguish the > virtual width/height from the physical width/height > * the framebuffer code needs to do something with the > virtual width/height/origin information > > Note that the wiki documentation on the semantics of the > virtual and physical height and width has it the wrong way > around -- the virtual size is the size of the allocated > buffer, and the physical size is the size of the display, > so the virtual size is always the same as or larger than > the physical. > > If the viewport size is set smaller than the physical > screen size, we ignore the viewport settings completely > and just display the physical screen area. > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > --- > include/hw/display/bcm2835_fb.h | 6 ++++-- > hw/display/bcm2835_fb.c | 28 ++++++++++++++++++++++------ > hw/misc/bcm2835_property.c | 21 +++++++++++++++------ > 3 files changed, 41 insertions(+), 14 deletions(-) Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
