From 7c2e4ad6d5f6cdfb9838e62d1ae80287ef4e1b63 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 16 May 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-05-16

---
 pc/vgaark2000pv.c | 187 +++++++++++++++++++++++++++++++++++++++++++++-
 pc/vgamach32.c    |  42 +++++++++++
 2 files changed, 228 insertions(+), 1 deletion(-)
 create mode 100644 pc/vgamach32.c

diff --git a/pc/vgaark2000pv.c b/pc/vgaark2000pv.c
index 5ef67aa4efde4b4a083a606206d260d9808a09ab..7c1a7dce200fe414223a252a99d57e9b91db68f5 100644
--- a/pc/vgaark2000pv.c
+++ b/pc/vgaark2000pv.c
@@ -9,13 +9,197 @@
 #include "screen.h"
 #include "vga.h"
 
+extern Bitmap gscreen;
+extern Cursor curcursor;
+
+static Lock ark2000pvlock;
+static ulong storage;
+static Point hotpoint;
+
 static void
-ark2000pvpage(int page)
+setark2000pvpage(int page)
 {
 	vgaxo(Seqx, 0x15, page);
 	vgaxo(Seqx, 0x16, page);
 }
 
+static void
+disable(void)
+{
+	uchar seq20;
+
+	seq20 = vgaxi(Seqx, 0x20) & ~0x08;
+	vgaxo(Seqx, 0x20, seq20);
+}
+
+static void
+enable(void)
+{
+	uchar seq20;
+
+	/*
+	 * Disable the cursor then configure for X-Windows style,
+	 * 64x64 and 4/8-bit colour depth.
+	 * Set cursor colours for 4/8-bit.
+	 */
+	seq20 = vgaxi(Seqx, 0x20) & ~0x1F;
+	vgaxo(Seqx, 0x20, seq20);
+	seq20 |= 0x1C;
+
+	vgaxo(Seqx, 0x26, Pwhite);
+	vgaxo(Seqx, 0x27, Pwhite);
+	vgaxo(Seqx, 0x28, Pwhite);
+	vgaxo(Seqx, 0x29, Pblack);
+	vgaxo(Seqx, 0x2A, Pblack);
+	vgaxo(Seqx, 0x2B, Pblack);
+
+	/*
+	 * Cursor storage is a 1Kb block located in the last 16Kb
+	 * of video memory. Crt25 is the index of which 1Kb block.
+	 */
+	storage = (vgaxi(Seqx, 0x10)>>6) & 0x03;
+	storage = (1024*1024)<<storage;
+	storage -= 1024;
+	vgaxo(Seqx, 0x25, 0x3C);
+
+	/*
+	 * Enable the cursor.
+	 */
+	vgaxo(Seqx, 0x20, seq20);
+}
+
+static void
+load(Cursor *c)
+{
+	uchar *p, seq20;
+	int x, y;
+
+	/*
+	 * Lock the display memory so we can update the
+	 * cursor bitmap if necessary.
+	 * If it's the same as the last cursor we loaded,
+	 * just make sure it's enabled.
+	 */
+	seq20 = vgaxi(Seqx, 0x20);
+	lock(&ark2000pvlock);
+	if(memcmp(c, &curcursor, sizeof(Cursor)) == 0){
+		vgaxo(Seqx, 0x20, 0x80|seq20);
+		unlock(&ark2000pvlock);
+		return;
+	}
+	memmove(&curcursor, c, sizeof(Cursor));
+
+	/*
+	 * Is linear addressing turned on? This will determine
+	 * how we access the cursor storage.
+	 */
+	if(vgaxi(Seqx, 0x10) & 0x10)
+		p = ((uchar*)gscreen.base) + storage;
+	else {
+		setark2000pvpage(storage>>16);
+		p = ((uchar*)gscreen.base) + (storage & 0xFFFF);
+	}
+
+	/*
+	 * The cursor is set in X11 mode which gives the following
+	 * truth table:
+	 *	and xor	colour
+	 *	 0   0	underlying pixel colour
+	 *	 0   1	underlying pixel colour
+	 *	 1   0	background colour
+	 *	 1   1	foreground colour
+	 * Put the cursor into the top-left of the 64x64 array.
+	 * The manual doesn't say what the data layout in memory is -
+	 * this worked out by trial and error.
+	 */
+	for(y = 0; y < 64; y++){
+		for(x = 0; x < 64/8; x++){
+			if(x < 16/8 && y < 16){
+				*p++ = c->clr[2*y + x]|c->set[2*y + x];
+				*p++ = c->set[2*y + x];
+			}
+			else {
+				*p++ = 0x00;
+				*p++ = 0x00;
+			}
+		}
+	}
+
+	/*
+	 * Set the cursor hotpoint and enable the cursor.
+	 */
+	hotpoint = c->offset;
+	vgaxo(Seqx, 0x20, 0x80|seq20);
+
+	unlock(&ark2000pvlock);
+}
+
+static int
+move(Point p)
+{
+	int x, xo, y, yo;
+
+	if(canlock(&ark2000pvlock) == 0)
+		return 1;
+
+	/*
+	 * Mustn't position the cursor offscreen even partially,
+	 * or it might disappear. Therefore, if x or y is -ve, adjust the
+	 * cursor origins instead.
+	 */
+	if((x = p.x+hotpoint.x) < 0){
+		xo = -x;
+		x = 0;
+	}
+	else
+		xo = 0;
+	if((y = p.y+hotpoint.y) < 0){
+		yo = -y;
+		y = 0;
+	}
+	else
+		yo = 0;
+
+	/*
+	 * Load the new values.
+	 */
+	vgaxo(Seqx, 0x2C, xo);
+	vgaxo(Seqx, 0x2D, yo);
+	vgaxo(Seqx, 0x21, (x>>8) & 0x0F);
+	vgaxo(Seqx, 0x22, x & 0xFF);
+	vgaxo(Seqx, 0x23, (y>>8) & 0x0F);
+	vgaxo(Seqx, 0x24, y & 0xFF);
+
+	unlock(&ark2000pvlock);
+	return 0;
+}
+
+Hwgc ark2000pvhwgc = {
+	"ark2000pvhwgc",
+	enable,
+	load,
+	move,
+	disable,
+
+	0,
+};
+
+static void
+ark2000pvpage(int page)
+{
+	/*
+	 * Shouldn't need to lock if linear addressing
+	 * is enabled.
+	 */
+	if((vgaxi(Seqx, 0x10) & 0x10) == 0 && hwgc == &ark2000pvhwgc){
+		lock(&ark2000pvlock);
+		setark2000pvpage(page);
+		unlock(&ark2000pvlock);
+	}
+	else
+		setark2000pvpage(page);
+}
+
 static Vgac ark2000pv = {
 	"ark2000pv",
 	ark2000pvpage,
@@ -27,4 +211,5 @@ void
 vgaark2000pvlink(void)
 {
 	addvgaclink(&ark2000pv);
+	addhwgclink(&ark2000pvhwgc);
 }
diff --git a/pc/vgamach32.c b/pc/vgamach32.c
new file mode 100644
index 0000000000000000000000000000000000000000..64aca73fdd01bd5db8cb5f684df2c42682eea0d1
--- /dev/null
+++ b/pc/vgamach32.c
@@ -0,0 +1,42 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+#include <libg.h>
+#include "screen.h"
+#include "vga.h"
+
+static void
+mach32page(int page)
+{
+	uchar ae, p;
+
+
+	p = (page & 0x0F)<<1;
+	p |= (page & 0x07)<<5;
+	outs(0x1CE, (p<<8)|0xB2);
+
+	outb(0x1CE, 0xAE);
+	ae = inb(0x1CE+1);
+
+	p = (page>>4) & 0x03;
+	p |= p<<2;
+	p |= ae & 0xF0;
+	outs(0x1CE, (p<<8)|0xAE);
+}
+
+static Vgac mach32 = {
+	"mach32",
+	mach32page,
+
+	0,
+};
+
+void
+vgamach32link(void)
+{
+	addvgaclink(&mach32);
+}