[U-Boot] [RFC] efi_loader: frame buffers in EFI GOP and DM_VIDEO

[Rob Clark]

On Wed, Oct 25, 2017 at 3:45 PM, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> Hello Alex, hello Simon,
>
> I have just been reading through efi_gop and video_uclass.c and there seems
> to be something missing in the support of video modes.
>
> U-Boot configuration knows the following color models:
>
> 16-color
> 256-color
> 32k (1:5:5:5)
> 64k (5:6:5)
> 16.8M (8:8:8)
>
> In lib/efi_loader/efi_gop.c I only found
>
> VIDEO_BPP32
> VIDEO_BPP16
> Patch a812241091ce efi_loader: Add DM_VIDEO support (Alexander Graf)
>
> Shouldn't gop_blt differentiate between 32k and 64k color mode?
> Unfortunately video_uclass.c cannot tell the difference!
> What about 4 and 8 bit modes?
>
> When I look at the coding in video_uclass.c, function video_clear it seems
> that this only correctly supports 32bit and 8bit mode.
> Patch 1acafc73bfc7 dm: video: Add a video uclass (Simon Glass)
>
> Shouldn't 4, 15 and 16 bit modes be added here?
>

(apologies for being a bit behind on u-boot mails but been busy on
other upstreams)

iirc UEFI only supports a subset of what u-boot supports (and I think
it is worse because u-boot doesn't do a good job of differentiating
between different component orders of a given bpp).. but we could
support more hw by not with the path that doesn't expose the scanout
buffer address and only supports blitting to scanout buffer (and doing
conversion as part of the blit).  I think it is mostly a matter of
someone who has this hw writing and testing the appropriate blit
paths..

BR,
-R