Re: [PATCH] move DAC register setting to linux.c

[Robert Millan]

Committed.

On Thu, Sep 10, 2009 at 11:03:16PM +0200, Robert Millan wrote:
> 
> It didn't really seem right that we were *setting* values in the DAC palette
> register in a function that was only meant to retrieve video mode information.
> 
> So I would rather move this to the Linux loader.  In the event that other
> loaders would need this facility, it can be moved into a shared function.
> 
> This has the advantage that we don't mess with the DAC palette in cases where
> this is not necessary (read: the vast majority of them).
> 
> -- 
> Robert Millan
> 
>   The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
>   how) you may access your data; but nobody's threatening your freedom: we
>   still allow you to remove your data and not access it at all."

> 2009-09-10  Robert Millan  <address@hidden>
> 
>       * video/i386/pc/vbe.c (grub_vbe_get_video_mode_info): Move packed
>       mode special handling (grub_vbe_bios_set_dac_palette_width() call)
>       from here ...
>       * loader/i386/linux.c [GRUB_MACHINE_PCBIOS]
>       (grub_linux_setup_video): ... to here (with some adjustments).
> 
> Index: video/i386/pc/vbe.c
> ===================================================================
> --- video/i386/pc/vbe.c       (revision 2583)
> +++ video/i386/pc/vbe.c       (working copy)
> @@ -286,24 +286,6 @@ grub_vbe_get_video_mode_info (grub_uint3
>  
>        /* Make copy of mode info block.  */
>        grub_memcpy (mode_info, mi_tmp, sizeof (*mode_info));
> -
> -      /* Packed mode.  Query DAC Palette width for color sizes.  */
> -      if (mode_info->bits_per_pixel <= 8)
> -     {
> -       int width = 8;
> -       status = 0;
> -
> -       if (controller_info.capabilities & GRUB_VBE_CAPABILITY_DACWIDTH)
> -         status = grub_vbe_bios_set_dac_palette_width (& width);
> -
> -       if (status != GRUB_VBE_STATUS_OK)
> -         /* 6 is default after mode reset.  */
> -         width = 6;
> -
> -       mode_info->red_mask_size = mode_info->green_mask_size
> -         = mode_info->blue_mask_size = width;
> -       mode_info->rsvd_mask_size = 0;
> -     }
>      }
>    else
>      /* Just clear mode info block if it isn't a VESA mode.  */
> Index: loader/i386/linux.c
> ===================================================================
> --- loader/i386/linux.c       (revision 2583)
> +++ loader/i386/linux.c       (working copy)
> @@ -33,6 +33,7 @@
>  #include <grub/video.h>
>  #include <grub/video_fb.h>
>  #include <grub/command.h>
> +#include <grub/i386/pc/vbe.h>
>  
>  #define GRUB_LINUX_CL_OFFSET         0x1000
>  #define GRUB_LINUX_CL_END_OFFSET     0x2000
> @@ -416,6 +417,33 @@ grub_linux_setup_video (struct linux_ker
>    params->reserved_mask_size = mode_info.reserved_mask_size;
>    params->reserved_field_pos = mode_info.reserved_field_pos;
>  
> +
> +#ifdef GRUB_MACHINE_PCBIOS
> +  /* VESA packed modes may come with zeroed mask sizes, which need
> +     to be set here according to DAC Palette width.  If we don't,
> +     this results in Linux displaying a black screen.  */
> +  if (mode_info.bpp <= 8)
> +    {
> +      struct grub_vbe_info_block controller_info;
> +      int status;
> +      int width = 8;
> +
> +      status = grub_vbe_bios_get_controller_info (&controller_info);
> +
> +      if (status == GRUB_VBE_STATUS_OK &&
> +       (controller_info.capabilities & GRUB_VBE_CAPABILITY_DACWIDTH))
> +     status = grub_vbe_bios_set_dac_palette_width (&width);
> +
> +      if (status != GRUB_VBE_STATUS_OK)
> +     /* 6 is default after mode reset.  */
> +     width = 6;
> +
> +      params->red_mask_size = params->green_mask_size
> +     = params->blue_mask_size = width;
> +      params->reserved_mask_size = 0;
> +    }
> +#endif
> +
>    return 0;
>  }
>  

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-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."