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

[Mark Cave-Ayland]

On 18/06/17 08:49, G 3 wrote:

> On Jun 18, 2017, at 2:50 AM, Mark Cave-Ayland wrote:
> 
>> 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.
> 
> If the user isn't satisfied with the default VGA resolutions, is there a
> way to add a set?

Not with this patch - it simply changes the way the registers are
accessed. I think the way forward here is to follow up with Gerd's patch
to expose the default width/height via the VGA registers and then update
Ben's driver to include this by default as previously discussed.


ATB,

Mark.