[OpenBIOS] [PATCH] vga.fs: add support for QEMU PCI MMIO register access

[Mark Cave-Ayland]

On 10/06/17 14:25, Mark Cave-Ayland wrote:

> Currently the driver works by using the legacy VGA ioports for programming
> the display. However this makes it much harder to configure e.g. multiple
> displays or VGA devices behind multiple PCI bridges.
> 
> If building for QEMU, default to using the QEMU PCI MMIO registers to program
> the display.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>
> ---
>  drivers/vga.fs |   85 ++++++++++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 68 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/vga.fs b/drivers/vga.fs
> index cbfa46c..d39b062 100644
> --- a/drivers/vga.fs
> +++ b/drivers/vga.fs
> @@ -47,6 +47,22 @@ fcode-version3
>  : ioc! ioc!-xt execute ;
>  : iow! iow!-xt execute ;
>  
> +" le-w!" (find-xt) value le-w!-xt
> +
> +: le-w! le-w!-xt execute ;
> +
> +\
> +\ PCI
> +\
> +
> +" pci-bar>pci-addr" (find-xt) value pci-bar>pci-addr-xt
> +: pci-bar>pci-addr pci-bar>pci-addr-xt execute ;
> +
> +h# 10 constant cfg-bar0    \ Framebuffer BAR
> +h# 18 constant cfg-bar2    \ QEMU MMIO ioport BAR
> +-1 value fb-addr
> +-1 value mmio-addr
> +
>  \
>  \ VGA registers
>  \
> @@ -55,12 +71,22 @@ h# 3c0 constant vga-addr
>  h# 3c8 constant dac-write-addr
>  h# 3c9 constant dac-data-addr
>  
> +defer vga-ioc!
> +
> +: vga-legacy-ioc!  ( val addr )
> +  ioc! 
> +;
> +
> +: vga-mmio-ioc!  ( val addr )
> +  h# 3c0 - h# 400 + mmio-addr + c!
> +;
> +
>  : vga-color!  ( r g b index -- )
>    \ Set the VGA colour registers
> -  dac-write-addr ioc! rot
> -  2 >> dac-data-addr ioc! swap
> -  2 >> dac-data-addr ioc!
> -  2 >> dac-data-addr ioc!
> +  dac-write-addr vga-ioc! rot
> +  2 >> dac-data-addr vga-ioc! swap
> +  2 >> dac-data-addr vga-ioc!
> +  2 >> dac-data-addr vga-ioc!
>  ;
>  
>  \
> @@ -86,17 +112,23 @@ h# 1 constant VBE_DISPI_ENABLED
>  \ Bochs VBE register writes
>  \
>  
> -: vbe-iow!  ( val addr -- )
> +defer vbe-iow!
> +
> +: vbe-legacy-iow!  ( val addr -- )
>    h# 1ce iow!
>    h# 1d0 iow!
>  ;
>  
> +: vbe-mmio-iow!  ( val addr -- )
> +  1 lshift h# 500 + mmio-addr + cr .s cr le-w!
> +;
> +
>  \
>  \ Initialise Bochs VBE mode
>  \
>  
>  : vbe-init  ( -- )
> -  h# 0 vga-addr ioc!    \ Enable blanking
> +  h# 0 vga-addr vga-ioc!    \ Enable blanking
>    VBE_DISPI_DISABLED VBE_DISPI_INDEX_ENABLE vbe-iow!
>    h# 0 VBE_DISPI_INDEX_X_OFFSET vbe-iow!
>    h# 0 VBE_DISPI_INDEX_Y_OFFSET vbe-iow!
> @@ -104,20 +136,14 @@ h# 1 constant VBE_DISPI_ENABLED
>    openbios-video-height VBE_DISPI_INDEX_YRES vbe-iow!
>    depth-bits VBE_DISPI_INDEX_BPP vbe-iow!
>    VBE_DISPI_ENABLED VBE_DISPI_INDEX_ENABLE vbe-iow!
> -  h# 0 vga-addr ioc!
> -  h# 20 vga-addr ioc!   \ Disable blanking
> +  h# 0 vga-addr vga-ioc!
> +  h# 20 vga-addr vga-ioc!   \ Disable blanking
>  ;
>  
>  \
> -\ PCI
> +\ PCI BAR mapping
>  \
>  
> -" pci-bar>pci-addr" (find-xt) value pci-bar>pci-addr-xt
> -: pci-bar>pci-addr pci-bar>pci-addr-xt execute ;
> -
> -h# 10 constant cfg-bar0    \ Framebuffer BAR
> --1 value fb-addr
> -
>  : map-fb ( -- )
>    cfg-bar0 pci-bar>pci-addr if   \ ( pci-addr.lo pci-addr.mid pci-addr.hi size )
>      " pci-map-in" $call-parent
> @@ -125,6 +151,32 @@ h# 10 constant cfg-bar0    \ Framebuffer BAR
>    then
>  ;
>  
> +: map-mmio ( -- )
> +  cfg-bar2 pci-bar>pci-addr if   \ ( pci-addr.lo pci-addr.mid pci-addr.hi size )
> +    " pci-map-in" $call-parent
> +    to mmio-addr
> +  then
> +;
> +
> +\
> +\ Legacy IO port or QEMU MMIO accesses
> +\
> +\ legacy: use standard VGA ioport registers
> +\ MMIO: use QEMU PCI MMIO VGA registers
> +\
> +\ If building for QEMU, default to MMIO access since it allows
> +\ programming of the VGA card regardless of its position in the
> +\ PCI topology
> +\
> +
> +[IFDEF] CONFIG_QEMU
> +['] vga-mmio-ioc! to vga-ioc!
> +['] vbe-mmio-iow! to vbe-iow!
> +[ELSE]
> +['] vga-legacy-ioc! to vga-ioc!
> +['] vbe-legacy-iow! to vbe-iow!
> +[THEN]
> +
>  \
>  \ Publically visible words
>  \
> @@ -181,6 +233,7 @@ headerless
>  \
>  
>  : qemu-vga-driver-install ( -- )
> +  map-mmio vbe-init
>    fb-addr -1 = if
>      map-fb fb-addr to frame-buffer-adr
>      default-font set-font
> @@ -193,8 +246,6 @@ headerless
>  ;
>  
>  : qemu-vga-driver-init
> -
> -  vbe-init
>    openbios-video-width encode-int " width" property
>    openbios-video-height encode-int " height" property
>    depth-bits encode-int " depth" property
> 

This passes all my local tests so I've applied it to master.


ATB,

Mark.