[PATCH 22/26] x86: video: Support copy framebuffer with probed devices

[Anatolij Gustschin]

On Tue, 19 May 2020 17:10:54 -0600
Simon Glass sjg at chromium.org wrote:

> For PCI video devices that are not mentioned in the devicetree, U-Boot
> does not bind a driver before relocation, since PCI is not fully probed
> at that point. Furthermore it is possible for the video device to be on
> a secondary bus which is not even scanned.
> 
> This is fine if the framebuffer is allocated in fixed memory, as it
> normally is on x86. But when using this as a copy framebuffer, we also
> need U-Boot to allocate its own cached framebuffer for working in. Since
> the video driver is never bound before relocation, the framebuffer size
> is never set and U-Boot does no allocation.
> 
> Add a new CONFIG option to reserve 16MB of memory for this eventuality.
> This allows vesa devices to use the copy framebuffer.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>

Reviewed-by: Anatolij Gustschin <agust at denx.de>