From: Alan Cox <alan@linux.intel.com>
Date: Wed, 27 May 2015 21:56:32 +0000 (+0100)
Subject: dragon-nx-32: commit initial bits of video development work
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=0f6565177f0965e0fd5c8673761b1ec69bcee26f;p=FUZIX.git

dragon-nx-32: commit initial bits of video development work

Not yet tested
---

diff --git a/Kernel/platform-dragon-nx32/kernel.def b/Kernel/platform-dragon-nx32/kernel.def
index daed265a..f5b907a7 100644
--- a/Kernel/platform-dragon-nx32/kernel.def
+++ b/Kernel/platform-dragon-nx32/kernel.def
@@ -5,6 +5,8 @@ U_DATA__TOTALSIZE           equ 0x300        ; 256+256+256 bytes.
 
 U_DATA_STASH                equ 0xFC00       ; FC00-FEFF
 
+VIDEO_BASE		    equ 0x0400	     ; 6K for the display
+VIDEO_END		    equ 0x1C00
 
 ; Have these defined so that lowlevel-6809.s can be used as-is
 SAM_USER macro
diff --git a/Kernel/platform-dragon-nx32/video.s b/Kernel/platform-dragon-nx32/video.s
new file mode 100644
index 00000000..71f2048b
--- /dev/null
+++ b/Kernel/platform-dragon-nx32/video.s
@@ -0,0 +1,255 @@
+	.module dragonvideo
+
+	; Methods provided
+	.globl _vid256x192
+	.globl _plot_char
+	.globl _scroll_up
+	.globl _scroll_down
+	.globl _clear_across
+	.globl _clear_lines
+	.globl _cursor_on
+	.globl _cursor_off
+	;
+	; Imports
+	;
+	.globl _fontdata_8x8
+
+	include "kernel.def"
+	include "../kernel09.def"
+
+	.area .text
+
+;
+;	Dragon video drivers
+;
+_vid256x192:
+	sta $ffc0
+	sta $ffc3
+	sta $ffc5
+	lda $ff22
+	anda #$07
+	ora #$f8
+	sta $ff22
+	rts
+
+;
+;	Compute the video base address
+;	A = X, B = Y
+;
+vidaddr:
+	ldy #VIDEO_BASE	; X is now the right column top line
+	leay a,y
+	clra
+	rorb	; 3 right is as good as 5 left	
+	rora
+	rorb
+	rora
+	rorb
+	rora	; D is now 32 * b
+	leay d,y
+	rts
+;
+;	plot_char(int8_t y, int8_t x, uint16_t c)
+;
+_plot_char:
+	pshs y
+	lda 4,s
+	bsr vidaddr		; preserves X (holding the char)
+	tfr x,d
+	rolb			; multiply by 8
+	rola
+	rolb
+	rola
+	rolb
+	rola
+	tfr d,x
+	leax _fontdata_8x8,x		; relative to font
+	lda ,x+			; simple 8x8 renderer for now
+	sta 0,y
+	lda ,x+
+	sta 32,y
+	lda ,x+
+	sta 64,y
+	lda ,x+
+	sta 96,y
+	lda ,x+
+	sta 128,y
+	lda ,x+
+	sta 160,y
+	lda ,x+
+	sta 192,y
+	lda ,x+
+	sta 224,y
+	puls y,pc
+
+;
+;	void scroll_up(void)
+;
+_scroll_up
+	pshs y
+	ldy VIDEO_BASE
+	leax 256,y
+vscrolln:
+	; Unrolled line by line copy
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	ldd ,x++
+	std ,y++
+	cmpy video_endptr
+	bne vscrolln
+	puls y,pc
+
+;
+;	void scroll_down(void)
+;
+_scroll_down:
+	pshs y
+	ldy VIDEO_END
+	leax -256,y
+vscrolld:
+	; Unrolled line by line loop
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	ldd ,--x
+	std ,--y
+	cmpx video_startptr
+	bne vscrolld
+	puls y,pc
+
+video_startptr:
+	.dw	VIDEO_BASE
+video_endptr:
+	.dw	VIDEO_END
+
+;
+;	clear_across(int8_t y, int8_t x, uint16_t l)
+;
+_clear_across:
+	pshs y
+	lda 4,s		; x into A, B already has y
+	jsr vidaddr	; Y now holds the address
+	tfr x,d		; Shuffle so we are writng to X and the counter
+	tfr y,x		; l is in d
+clearnext:
+	clr ,x
+	clr 32,x
+	clr 64,x
+	clr 96,x
+	clr 128,x
+	clr 160,x
+	clr 192,x
+	clr 224,x
+	leax 1,x
+	deca
+	bne clearnext
+	puls y,pc
+;
+;	clear_lines(int8_t y, int8_t ct)
+;
+_clear_lines:
+	pshs y
+	clra			; b holds Y pos already
+	jsr vidaddr		; y now holds ptr to line start
+	tfr y,x
+	clra
+	clrb
+wipel:
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	std ,x++
+	dec 4,s			; count of lines
+	bne wipel
+	puls y,pc
+
+_cursor_on
+	pshs y
+	lda  4,s
+	jsr vidaddr
+	tfr y,x
+	puls y
+	stx cursor_save
+	; Fall through
+_cursor_off
+	ldx cursor_save
+	com ,x
+	com 32,x
+	com 64,x
+	com 96,x
+	com 128,x
+	com 160,x
+	com 192,x
+	com 224,x
+	rts
+
+	.area .data
+cursor_save:
+	.dw	0