On 23.11.2022 16:45, Roger Pau Monne wrote:
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -864,6 +864,26 @@ static UINTN __init
> efi_find_gop_mode(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop,
> UINTN gop_mode = ~0, info_size, size;
> unsigned int i;
>
> + if ( (!cols || !rows) && gop->Mode->Mode < gop->Mode->MaxMode )
> + {
> + /* If no (valid) resolution suggested, try to use the current mode.
> */
> + status = gop->QueryMode(gop, gop->Mode->Mode, &info_size,
> &mode_info);
> + if ( EFI_ERROR(status) )
> + PrintErr(L"Invalid current graphics mode\r\n");
> + else if ( mode_info->PixelFormat < PixelBltOnly )
> + return gop->Mode->Mode;
> + else
> + {
> + /*
> + * Try to find a mode with the same resolution and a valid pixel
> + * format.
> + */
> + cols = mode_info->HorizontalResolution;
> + rows = mode_info->VerticalResolution;
For these I think you want to replace cols and rows individually, i.e.
if ( !cols )
cols = mode_info->HorizontalResolution;
if ( !rows )
rows = mode_info->VerticalResolution;
whereas ...
> + depth = 0;
... this case looks more complicated, as 0 is also already legitimate
as a value to come in. By zapping a non-zero incoming value you may end
up switching modes _just_ to alter depth, and then you may not fulfill
what was requested. For now I think depth simply wants leaving alone
here (and perhaps using the current mode's value if the incoming value
was zero, thus eliminating the need for a mode change in certain cases).
In a separate change we might then enhance this, e.g. by finding a
supported mode matching geometry but only coming close for "depth".
Jan
