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

Heinrich Schuchardt
2022-02-27T15:35:29Z

On 2/27/22 15:40, Alexander Graf wrote:
> 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

Please, enable the device on RISC-V too.

Best regards

Heinrich

>
> 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
>