qemu/include/hw/display
Peter Maydell 01f18af98b hw/display/bcm2835_fb: Fix handling of virtual framebuffer
The raspi framebuffir in bcm2835_fb supports the definition
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.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180814144436.679-7-peter.maydell@linaro.org
2018-08-24 13:17:49 +01:00
..
bcm2835_fb.h hw/display/bcm2835_fb: Fix handling of virtual framebuffer 2018-08-24 13:17:49 +01:00
bochs-vbe.h vga: move bochs vbe defines to header file 2018-05-24 10:42:13 +02:00
dpcd.h Clean up decorations and whitespace around header guards 2016-07-12 16:20:46 +02:00
ramfb.h hw/display: add standalone ramfb device 2018-06-18 11:22:15 +02:00
vga.h hw/display/vga: extract public API from i386/pc to "hw/display/vga.h" 2017-12-18 17:07:02 +03:00
xlnx_dp.h hw/display: Use the IEC binary prefix definitions 2018-07-02 15:41:13 +02:00