[SeaBIOS] [PATCH 2/4] SeaVGABIOS/vbe: Query driver for scanline pitch

[Kevin O'Connor]

On Fri, Mar 17, 2017 at 05:49:40PM +0100, Patrick Rudolph wrote:
> Query the driver for the real scanline pitch in bytes.
> 
> As cbvga doesn't change the pitch on mode change, always
> return the same pitch, that might exceed width times Bytes-per-pixel.
> 
> Signed-off-by: Patrick Rudolph <siro at das-labor.org>
> ---
>  vgasrc/bochsvga.c |  5 +++++
>  vgasrc/bochsvga.h |  1 +
>  vgasrc/cbvga.c    |  7 +++++++
>  vgasrc/clext.c    |  5 +++++
>  vgasrc/stdvga.c   |  5 +++++
>  vgasrc/vbe.c      |  2 +-
>  vgasrc/vgahw.h    | 10 ++++++++++
>  vgasrc/vgautil.h  |  3 +++
>  8 files changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/vgasrc/bochsvga.c b/vgasrc/bochsvga.c
> index ec5d101..458b3a8 100644
> --- a/vgasrc/bochsvga.c
> +++ b/vgasrc/bochsvga.c
> @@ -310,6 +310,11 @@ bochsvga_save_restore(int cmd, u16 seg, void *data)
>      return ret + (VBE_DISPI_INDEX_Y_OFFSET-VBE_DISPI_INDEX_XRES+1)*sizeof(u16);
>  }
>  
> +int
> +bochsvga_get_linesize(struct vgamode_s *vmode_g)
> +{
> +    return DIV_ROUND_UP(vmode_g->width * vga_bpp(vmode_g), 8);
> +}
>  
>  /****************************************************************
>   * Mode setting
> diff --git a/vgasrc/bochsvga.h b/vgasrc/bochsvga.h
> index ae5f75d..40ce6f1 100644
> --- a/vgasrc/bochsvga.h
> +++ b/vgasrc/bochsvga.h
> @@ -52,6 +52,7 @@ int bochsvga_get_dacformat(struct vgamode_s *vmode_g);
>  int bochsvga_set_dacformat(struct vgamode_s *vmode_g, int val);
>  int bochsvga_save_restore(int cmd, u16 seg, void *data);
>  int bochsvga_set_mode(struct vgamode_s *vmode_g, int flags);
> +int bochsvga_get_linesize(struct vgamode_s *vmode_g);
>  int bochsvga_setup(void);
>  
>  #endif // bochsvga.h
> diff --git a/vgasrc/cbvga.c b/vgasrc/cbvga.c
> index 87ec77e..50e6e69 100644
> --- a/vgasrc/cbvga.c
> +++ b/vgasrc/cbvga.c
> @@ -123,6 +123,13 @@ cbvga_set_mode(struct vgamode_s *vmode_g, int flags)
>      return 0;
>  }
>  
> +int
> +cbvga_get_linesize(struct vgamode_s *vmode_g)
> +{
> +    /* Can't change mode, always report active pitch. */
> +    return GET_GLOBAL(CBlinelength);
> +}
> +
>  #define CB_TAG_FRAMEBUFFER      0x0012
>  struct cb_framebuffer {
>      u32 tag;
> diff --git a/vgasrc/clext.c b/vgasrc/clext.c
> index da8b790..08bc9b5 100644
> --- a/vgasrc/clext.c
> +++ b/vgasrc/clext.c
> @@ -376,6 +376,11 @@ clext_save_restore(int cmd, u16 seg, void *data)
>      return stdvga_save_restore(cmd, seg, data);
>  }
>  
> +int
> +clext_get_linesize(struct vgamode_s *vmode_g)
> +{
> +    return DIV_ROUND_UP(vmode_g->width * vga_bpp(vmode_g), 8);
> +}
>  
>  /****************************************************************
>   * Mode setting
> diff --git a/vgasrc/stdvga.c b/vgasrc/stdvga.c
> index 886deca..0e24297 100644
> --- a/vgasrc/stdvga.c
> +++ b/vgasrc/stdvga.c
> @@ -321,6 +321,11 @@ stdvga_set_dacformat(struct vgamode_s *vmode_g, int val)
>      return -1;
>  }
>  
> +int
> +stdvga_get_linesize(struct vgamode_s *vmode_g)
> +{
> +    return DIV_ROUND_UP(vmode_g->width * vga_bpp(vmode_g), 8);
> +}
>  
>  /****************************************************************
>   * Save/Restore state
> diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c
> index facad19..724c1ba 100644
> --- a/vgasrc/vbe.c
> +++ b/vgasrc/vbe.c
> @@ -107,7 +107,7 @@ vbe_104f01(struct bregs *regs)
>      // Basic information about mode.
>      int width = GET_GLOBAL(vmode_g->width);
>      int height = GET_GLOBAL(vmode_g->height);
> -    int linesize = DIV_ROUND_UP(width * vga_bpp(vmode_g), 8);
> +    int linesize = vgahw_get_linesize(vmode_g);
>      SET_FARVAR(seg, info->bytes_per_scanline, linesize);
>      SET_FARVAR(seg, info->xres, width);
>      SET_FARVAR(seg, info->yres, height);
> diff --git a/vgasrc/vgahw.h b/vgasrc/vgahw.h
> index dab2b4d..5839643 100644
> --- a/vgasrc/vgahw.h
> +++ b/vgasrc/vgahw.h
> @@ -139,4 +139,14 @@ static inline int vgahw_save_restore(int cmd, u16 seg, void *data) {
>      return stdvga_save_restore(cmd, seg, data);
>  }
>  
> +static inline int vgahw_get_linesize(struct vgamode_s *vmode_g) {
> +    if (CONFIG_VGA_CIRRUS)
> +        return clext_get_linesize(vmode_g);
> +    if (CONFIG_VGA_BOCHS)
> +        return bochsvga_get_linesize(vmode_g);
> +    if (CONFIG_VGA_COREBOOT)
> +        return cbvga_get_linesize(vmode_g);
> +    return stdvga_get_linesize(vmode_g);
> +}

Minor nit - I think it would be preferable if this was:

static inline int vgahw_get_linesize(struct vgamode_s *vmode_g) {
    if (CONFIG_VGA_COREBOOT)
        return cbvga_get_linesize(vmode_g);
    return stdvga_get_linesize(vmode_g);
}

to reduce the duplicate code in the cirrus/bochs implementations.

Thanks.
-Kevin