Comment # 12 on bug 1219180 from Joey Lee

Hi Thomas,

(In reply to Thomas Zimmermann from comment #6)
> Here are the results of my investigation so far. The kernel tries to acquire
> the UEFI boot framebuffer via find_gop() [1]. It fails for all available
> results at the pixel_format test at [2]. The firmware only supports the
> BitBlt() EFI call to read/write framebuffer data. It's a boot service, so
> it's gone after the kernel initialized. We cannot use it.
> 
> I've tested with kernel's going back to v6.4. It's always reproducible.
> 
> To fix this problem, we have modify qemu's OVMF firmware to provide a pixel
> format and a framebuffer to which we can memcpy(). AFAICT a pixel format of
> PIXEL_BIT_MASK [3] would do this.
> 
> [1]
> https://elixir.bootlin.com/linux/v6.8/source/drivers/firmware/efi/libstub/
> gop.c#L521
> [2]
> https://elixir.bootlin.com/linux/v6.8/source/drivers/firmware/efi/libstub/
> gop.c#L489
> [3]
> https://elixir.bootlin.com/linux/v6.8/source/drivers/firmware/efi/libstub/
> efistub.h#L519

Could you please teach me how to create a qemu of aarch64 with graphics window?
I used the following qemu command for launching a aarch64 guest. But it always
only shows message on terminal console. Not graphic window:

qemu-system-aarch64 \
-m 4096 -cpu cortex-a57 -smp 4 -M virt \
-drive
if=pflash,format=raw,readonly,file=/usr/share/qemu/aavmf-aarch64-code.bin \
-drive
if=pflash,format=raw,file=/home/joeyli/qemu-vm/openSUSE-MicroOS-aarch64-vars-store.bin
\
-serial mon:stdio \
-net nic,model=virtio -net nic,model=virtio -net
bridge,br=br0,helper=/usr/libexec/qemu-bridge-helper \
-drive
if=none,file=/home/joeyli/iso/openSUSE-MicroOS-DVD-aarch64-Current.iso,id=hd0
-device virtio-blk-device,drive=hd0  \
-drive
if=none,file=/home/joeyli/qemu-vm/openSUSE-MicroOS-aarch64-efi.qcow2,id=hd1 
-device virtio-blk-device,drive=hd1 -vnc :93

Thanks!