\
\ Fcode payload for QEMU TCX graphics card
\
\ This is the Forth source for an Fcode payload to initialise
\ the QEMU TCX graphics card.
\
\ (C) Copyright 2013 Mark Cave-Ayland
\

fcode-version3

\
\ Instead of using fixed values for the framebuffer address and the width
\ and height, grab the ones passed in by QEMU/generated by OpenBIOS
\

: (find-xt)   \ ( str len -- xt | -1 )
  $find if
    exit
  else
    2drop
    -1
  then
;

: (is-openbios)  \ ( -- true | false )
  " openbios-video-width" (find-xt) -1 <> if
    -1
  else
    0
  then
;

" openbios-video-width" (find-xt) cell+ value openbios-video-width-xt
" openbios-video-height" (find-xt) cell+ value openbios-video-height-xt
" depth-bits" (find-xt) cell+ value depth-bits-xt
" line-bytes" (find-xt) cell+ value line-bytes-xt

: openbios-video-width
  (is-openbios) if
    openbios-video-width-xt @
  else
    h# 400
  then
;

: openbios-video-height
  (is-openbios) if
    openbios-video-height-xt @
  else
    h# 300
  then
;

: depth-bits
  (is-openbios) if
    depth-bits-xt @
  else
    h# 8
  then
;

: line-bytes
  (is-openbios) if
    line-bytes-xt @
  else
    h# 400
  then
;

\
\ Registers
\

h# 0 constant tcx-off-rom
h# 10000 constant /tcx-off-rom

h# 200000 constant tcx-off-cmap
h# 4000 constant /tcx-off-cmap-24
h# 4 constant /tcx-off-cmap-8

h# 240000 constant tcx-off-dhc
h# 4000 constant /tcx-off-dhc-24
h# 4 constant /tcx-off-dhc-8

h# 280000 constant tcx-off-alt
h# 8000 constant /tcx-off-alt-24
h# 1 constant /tcx-off-alt-8

h# 301000 constant tcx-off-thc-24
h# 300000 constant tcx-off-thc-8
h# 1000 constant /tcx-off-thc-24
h# 81c constant /tcx-off-thc-8

h# 701000 constant tcx-off-tec
h# 1000 constant /tcx-off-tec

h# 800000 constant tcx-off-dfb8
h# 100000 constant /tcx-off-dfb8

h# 2000000 constant tcx-off-dfb24
h# 400000 constant /tcx-off-dfb24-24
h# 1 constant /tcx-off-dfb24-8

h# 4000000 constant tcx-off-stip
h# 800000 constant /tcx-off-stip

h# 6000000 constant tcx-off-blit
h# 800000 constant /tcx-off-blit

h# a000000 constant tcx-off-rdfb32
h# 400000 constant /tcx-off-rdfb32-24
h# 1 constant /tcx-off-rdfb32-8

h# c000000 constant tcx-off-rstip
h# 800000 constant /tcx-off-rstip-24
h# 1 constant /tcx-off-rstip-8

h# e000000 constant tcx-off-rblit
h# 800000 constant /tcx-off-rblit-24
h# 1 constant /tcx-off-rblit-8

: >tcx-reg-spec ( offset size -- encoded-reg )
  >r 0 my-address d+ my-space encode-phys r> encode-int encode+
;

: tcx-8bit-reg
  \ WARNING: order is important (at least to Solaris)
  tcx-off-dfb8 /tcx-off-dfb8 >tcx-reg-spec
  tcx-off-dfb24 /tcx-off-dfb24-8 >tcx-reg-spec encode+
  tcx-off-stip /tcx-off-stip >tcx-reg-spec encode+
  tcx-off-blit /tcx-off-blit >tcx-reg-spec encode+
  tcx-off-rdfb32 /tcx-off-rdfb32-8 >tcx-reg-spec encode+
  tcx-off-rstip /tcx-off-rstip-8 >tcx-reg-spec encode+
  tcx-off-rblit /tcx-off-rblit-8 >tcx-reg-spec encode+
  tcx-off-tec /tcx-off-tec >tcx-reg-spec encode+
  tcx-off-cmap /tcx-off-cmap-8 >tcx-reg-spec encode+
  tcx-off-thc-8 /tcx-off-thc-8 >tcx-reg-spec encode+
  tcx-off-rom /tcx-off-rom >tcx-reg-spec encode+
  tcx-off-dhc /tcx-off-dhc-8 >tcx-reg-spec encode+
  tcx-off-alt /tcx-off-alt-8 >tcx-reg-spec encode+
  " reg" property
;

: tcx-24bit-reg
  \ WARNING: order is important (at least to Solaris)
  tcx-off-dfb8 /tcx-off-dfb8 >tcx-reg-spec
  tcx-off-dfb24 /tcx-off-dfb24-24 >tcx-reg-spec encode+
  tcx-off-stip /tcx-off-stip >tcx-reg-spec encode+
  tcx-off-blit /tcx-off-blit >tcx-reg-spec encode+
  tcx-off-rdfb32 /tcx-off-rdfb32-24 >tcx-reg-spec encode+
  tcx-off-rstip /tcx-off-rstip-24 >tcx-reg-spec encode+
  tcx-off-rblit /tcx-off-rblit-24 >tcx-reg-spec encode+
  tcx-off-tec /tcx-off-tec >tcx-reg-spec encode+
  tcx-off-cmap /tcx-off-cmap-24 >tcx-reg-spec encode+
  tcx-off-thc-24 /tcx-off-thc-24 >tcx-reg-spec encode+
  tcx-off-rom /tcx-off-rom >tcx-reg-spec encode+
  tcx-off-dhc /tcx-off-dhc-24 >tcx-reg-spec encode+
  tcx-off-alt /tcx-off-alt-24 >tcx-reg-spec encode+
  " reg" property
;

: do-map-in ( offset size -- virt )
  >r my-space r> " map-in" $call-parent
;

: do-map-out ( virt size )
  " map-out" $call-parent
;

\
\ DAC
\

-1 value tcx-dac
-1 value /tcx-dac
-1 value fb-addr

: dac! ( data reg# -- )
  >r dup 2dup bljoin r> tcx-dac + l!
;

external

: color!  ( r g b c# -- )
  0 dac!       ( r g b )
  swap rot     ( b g r )
  4 dac!       ( b g )
  4 dac!       ( b )
  4 dac!       (  )
;

headerless

\
\ Mapping
\

: dac-map
  tcx-off-cmap /tcx-dac do-map-in to tcx-dac
;

: fb-map
  tcx-off-dfb8 h# c0000 do-map-in to fb-addr
;

: map-regs
  dac-map fb-map
;

\
\ Installation
\

" SUNW,tcx" device-name
" display" device-type

: qemu-tcx-driver-install ( -- )
  tcx-dac -1 = if
    map-regs

    \ Initial pallette taken from Sun's "Writing FCode Programs"
    h# ff h# ff h# ff h# 0  color!    \ Background white
    h# 0  h# 0  h# 0  h# ff color!    \ Foreground black
    h# 64 h# 41 h# b4 h# 1  color!    \ SUN-blue logo

    fb-addr to frame-buffer-adr
    default-font set-font

    \ Sun TCX adapters don't have an address property, but it is useful for
    \ OpenBIOS developers. Unfortunately NetBSD SPARC32 has a bug that causes
    \ it to fail initialising TCX if the address property is present; so work
    \ around this by adding an underscore prefix
    frame-buffer-adr encode-int " _address" property

    openbios-video-width openbios-video-height over char-width / over char-height /
    fb8-install
  then
;

: qemu-tcx-driver-init

  \ Handle differences between 8-bit/24-bit mode
  depth-bits 8 = if
    tcx-8bit-reg
    /tcx-off-cmap-8 to /tcx-dac
    " true" encode-string " tcx-8-bit" property
  else
    tcx-24bit-reg
    /tcx-off-cmap-24 to /tcx-dac

    \ Even with a 24-bit enabled TCX card, the control plane is
    \ used in 8-bit mode. So force the video subsystem into 8-bit
    \ mode before initialisation.
    8 depth-bits-xt !
    openbios-video-width line-bytes-xt !
  then

  h# 1d encode-int " vbporch" property
  h# a0 encode-int " hbporch" property
  h# 06 encode-int " vsync" property
  h# 88 encode-int " hsync" property
  h# 03 encode-int " vfporch" property
  h# 18 encode-int " hfporch" property
  h# 03dfd240 encode-int " pixfreq" property
  h# 3c encode-int " vfreq" property

  openbios-video-height encode-int " height" property
  openbios-video-width encode-int " width" property
  line-bytes encode-int " linebytes" property

  h# 39 encode-int 0 encode-int encode+ " intr" property
  5 encode-int " interrupts" property

  ['] qemu-tcx-driver-install is-install
;

qemu-tcx-driver-init

end0