[PATCH 0/4] Add support for QEMU's ramfb display

Alexander Graf
2022-02-27T14:40:54Z

QEMU implements multiple ways to expose graphics output to the virt
machine, but most of them are incompatible with hardware virtualization.

The one that does work reliably is ramfb. It's a very simple mechanism
in which the guest reserves a memory region for the frame buffer and then
notifies the host about its location and properties. The host then just
displays the contents of the frame buffer on screen.

This patch set adds support to drive the ramfb device in our QEMU arm
targets. Theoretically, it should work as is with any of the other
architectures as well though.

With this driver, we have a very simple, KVM compatible way to expose
GOP via UEFI to payloads and thus enable development and testing of
graphical OS functionality with QEMU's -M virt.

Alexander Graf (4):
qfw: Add WRITE definition
ramfb: Add driver for ramfb display
qfw: Spawn ramfb device if its file is present
qemu-arm*: Enable ramfb by default

arch/arm/Kconfig | 4 ++
board/emulation/qemu-arm/qemu-arm.c | 14 ++++
drivers/misc/qfw.c | 23 ++++++
drivers/video/Kconfig | 8 +++
drivers/video/MAINTAINERS | 4 ++
drivers/video/Makefile | 1 +
drivers/video/ramfb.c | 104 ++++++++++++++++++++++++++++
include/configs/qemu-arm.h | 9 +++
include/qfw.h | 1 +
9 files changed, 168 insertions(+)
create mode 100644 drivers/video/MAINTAINERS
create mode 100644 drivers/video/ramfb.c

--
2.32.0