在2024年5月17日五月 上午2:44，Heinrich Schuchardt写道：
[...]
Hi Heinrich,
>>
>> plat = dev_get_uclass_plat(vdev);
>>+ ops = video_get_ops(vid);
>> fb_base = IS_ENABLED(CONFIG_VIDEO_COPY) ? plat->copy_base : plat->base;
>
> Wasn't this line introduced to handle the video sync case by pointing
> the EFI application to target framebuffer?
This is used to handle the case that U-Boot itself is performing a copy
from U-Boot's shadow buffer to the target buffer.
However, in virtio-gpu (and some other driver like syncoam,seps525, ste,mcde)
cases hardware needs to be notified for any update to the framebuffer.
For those hardwares if application just write to target framebuffer the display
won't be updated. Hence we must direct applications to call BLT to allow
hardware
being notified when framebuffer is changed.
Thanks
>
> Best regards
>
> Heinrich
>
--
- Jiaxun
