From 54421e13fd298dca059956eca757e2b262c2b57f Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Sun, 14 Dec 2014 18:23:06 +0000
Subject: [PATCH] vdp1: Allow mixed VDP/non VDP

We add a .equ which indicates whether the vdp1 driver should provide the
functions for vt.c or ones that can be wrapped. For MSX we are happy as we
are but for MTX512 we can support a VDP and a 6845 at the same time.
---
 Kernel/dev/vdp1.s          | 49 +++++++++++++++++++++++++++-----------
 Kernel/platform-msx1/vdp.s | 15 +++++++++++-
 2 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/Kernel/dev/vdp1.s b/Kernel/dev/vdp1.s
index 8d2b4640..9e79c67e 100644
--- a/Kernel/dev/vdp1.s
+++ b/Kernel/dev/vdp1.s
@@ -1,14 +1,14 @@
             .module vdp
 
 	    ; video driver
-	    .globl _scroll_up
-	    .globl _scroll_down
-	    .globl _plot_char
-	    .globl _clear_lines
-	    .globl _clear_across
-	    .globl _cursor_on
-	    .globl _cursor_off
-	    .globl _cursorpos
+	    .globl scroll_up
+	    .globl scroll_down
+	    .globl plot_char
+	    .globl clear_lines
+	    .globl clear_across
+	    .globl cursor_on
+	    .globl cursor_off
+	    .globl cursorpos
 
 	    .globl _vdpport
 
@@ -46,7 +46,7 @@ vdpout:	    ld bc, (_vdpport)
 ;
 
 
-_videopos:	; turn E=Y D=X into HL = addr
+videopos:	; turn E=Y D=X into HL = addr
 	        ; pass B = 0x40 if writing
 	        ; preserves C
 	    ld a, e			; 0-24 Y
@@ -68,7 +68,10 @@ _videopos:	; turn E=Y D=X into HL = addr
 ;
 ;	Eww.. wonder if VT should provide a hint that its the 'next char'
 ;
-_plot_char: pop hl
+		.if VDP_DIRECT
+_plot_char:
+		.endif
+plot_char:  pop hl
 	    pop de			; D = x E = y
 	    pop bc
 	    push bc
@@ -76,7 +79,7 @@ _plot_char: pop hl
 	    push hl
 plotit:
 	    ld b, #0x40			; writing
-	    call _videopos
+	    call videopos
 	    ld a, c
 plotit2:
 	    ld bc, (_vdpport)
@@ -101,7 +104,10 @@ scrollbuf:   .ds		40
 ;
 ;	We don't yet use attributes...
 ;
+		.if VDP_DIRECT
 _scroll_down:
+		.endif
+scroll_down:
 	    ret
 	    ld b, #23
 	    ld de, #0x3C0	; start of bottom line
@@ -129,7 +135,10 @@ upline:
 	    djnz upline
 	    ret
 
+		.if VDP_DIRECT
 _scroll_up:
+		.endif
+scroll_up:
 	    ret
 	    ld b, #23
 	    ld de, #40		; start of second line
@@ -157,7 +166,10 @@ downline:   push bc
 	    djnz downline
 	    ret
 
+		.if VDP_DIRECT
 _clear_lines:
+		.endif
+clear_lines:
 	    pop hl
 	    pop de	; E = line, D = count
 	    push de
@@ -165,7 +177,7 @@ _clear_lines:
 	    ld c, d
 	    ld d, #0
 	    ld b, #0x40
-	    call _videopos
+	    call videopos
 	    ld e, c
 	    ld bc, (_vdpport)
 	    out (c), l
@@ -183,7 +195,10 @@ l1:	    out (c), a		; Inner loop clears a line, outer counts
 	    jr nz, l2
 	    ret
 
+		.if VDP_DIRECT
 _clear_across:
+		.endif
+clear_across:
 	    pop hl
 	    pop de	; DE = coords
 	    pop bc	; C = count
@@ -191,7 +206,7 @@ _clear_across:
 	    push de
 	    push hl
 	    ld b, #0x40
-	    call _videopos
+	    call videopos
 	    ld a, c
 	    ld bc, (_vdpport)
 	    out (c), l
@@ -206,14 +221,17 @@ l3:	    out (c), a
 ;
 ;	FIXME: should use attribute blink flag not a char
 ;
+		.if VDP_DIRECT
 _cursor_on:
+		.endif
+cursor_on:
 	    pop hl
 	    pop de
 	    push de
 	    push hl
 	    ld (cursorpos), de
 	    ld b, #0x00			; reading
-	    call _videopos
+	    call videopos
 	    ld a, c
 	    ld bc, (_vdpport)
 	    out (c), l			; address
@@ -225,7 +243,10 @@ _cursor_on:
 	    ld a, #'_'			; write the cursor
 	    jp plotit2
 
+		.if VDP_DIRECT
 _cursor_off:
+		.endif
+cursor_off:
 	    ld de, (cursorpos)
 	    ld a, (cursorpeek)
 	    ld c, a
diff --git a/Kernel/platform-msx1/vdp.s b/Kernel/platform-msx1/vdp.s
index a35d9410..48d492b5 100644
--- a/Kernel/platform-msx1/vdp.s
+++ b/Kernel/platform-msx1/vdp.s
@@ -3,11 +3,24 @@
             .include "kernel.def"
             .include "../kernel.def"
 
-	    .include "../dev/vdp1.s"
 
 
 	    .area _COMMONMEM
 
+	    .globl _cursor_on
+	    .globl _cursor_off
+	    .globl _clear_across
+	    .globl _clear_lines
+	    .globl _scroll_up
+	    .globl _scroll_down
+	    .globl _plot_char
+
+;
+; VDP routines are directly hooked into the vt layer
+;
+VDP_DIRECT	.equ	1
+
+	    .include "../dev/vdp1.s"
 ;
 ;	FIXME: should use vdpport, but right now vdpport is in data not
 ;	common space.
-- 
2.34.1