From e5cde678b6855f39c412b2801c9763c33d5f7d8c Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 7 Nov 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-11-07

---
 gnot/screen.h |  1 +
 pc/fns.h      |  1 +
 pc/l.s        | 15 +++++++++++++++
 pc/screen.h   |  1 +
 pc/vga.c      | 29 ++++++++++++++++++++---------
 port/devbit.c | 26 ++++++++++++++++++++++----
 port/devenv.c |  3 +++
 ss/screen.h   |  1 +
 8 files changed, 64 insertions(+), 13 deletions(-)

diff --git a/gnot/screen.h b/gnot/screen.h
index 04fd048b804c96347861a49ecae322422183ad7f..f7c92d1c1306c0819fc85c7ab4006538f645beea 100644
--- a/gnot/screen.h
+++ b/gnot/screen.h
@@ -19,6 +19,7 @@ struct Cursorinfo{
 	Cursor;
 	Lock;
 	int	visible;	/* on screen */
+	int	disable;	/* from being used */
 	Rectangle r;		/* location */
 };
 
diff --git a/pc/fns.h b/pc/fns.h
index 853a1b447134bc2c4aac1ab4816357eed074e5c8..2f53c8efda62be0cd98d8198355818e5b7f0dbe0 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -34,6 +34,7 @@ void	inss(int, void*, int);
 void	insl(int, void*, int);
 ulong	isamem(int);
 void	kbdinit(void);
+void	l0update(uchar*, uchar*, int);
 void	mathinit(void);
 void	mmuinit(void);
 int	modem(int);
diff --git a/pc/l.s b/pc/l.s
index d2bf38e15ee9960166757e8bef1f9b96ca0fe125..9492a7ba1f98e50496e6435f18daf49aec85a5c1 100644
--- a/pc/l.s
+++ b/pc/l.s
@@ -633,3 +633,18 @@ TEXT	config(SB),$0
 	OUTB
 	OUTB
 	RET
+
+/*
+ *  copy bytes to screen memory for ldepth 0 screen
+ */
+TEXT	l0update(SB),$0
+	XORL	AX,AX
+	MOVL	len+8(FP),CX
+	MOVL	from+0(FP),BX
+	MOVL	to+4(FP),DX
+l00:
+	MOVB	-1(BX)(CX*1),AL
+	MOVB	cswizzle(SB)(AX*1),AL
+	MOVB	AL,-1(DX)(CX*1)
+	LOOP	l00
+	RET
diff --git a/pc/screen.h b/pc/screen.h
index a3dd699a525856e050fc5a74688ba926b93df537..8a58efe952162df5f165aa48efa4bb6d6fd0de46 100644
--- a/pc/screen.h
+++ b/pc/screen.h
@@ -19,6 +19,7 @@ struct Cursorinfo{
 	Cursor;
 	Lock;
 	int	visible;	/* on screen */
+	int	disable;	/* from being used */
 	Rectangle r;		/* location */
 };
 
diff --git a/pc/vga.c b/pc/vga.c
index 685425a2392327545fc1042f7d6c88d738291f1b..8038d8776365802dd2f719c7f25119e501cd26ba 100644
--- a/pc/vga.c
+++ b/pc/vga.c
@@ -250,8 +250,8 @@ setscreen(int maxx, int maxy, int ldepth)
 	gscreen.r.max = Pt(maxx, maxy);
 	gscreen.clipr.max = gscreen.r.max;
 	len = gscreen.width * 4 * maxy;
-	gscreen.base = malloc(len);
-	memset((void*)gscreen.base, 0xff, len);
+	gscreen.base = ((ulong*)malloc(len+2*1024))+256;
+	memset((char*)gscreen.base, 0xff, len);
 
 	/*
 	 *  set string pointer to upper left
@@ -325,7 +325,6 @@ mbbpt(Point p)
 		mbb.max.x = p.x+1;
 	if (p.y >= mbb.max.y)
 		mbb.max.y = p.y+1;
-	screenupdate();
 }
 
 void
@@ -403,27 +402,39 @@ screenupdate(void)
 {
 	uchar *sp, *hp, *se;
 	int y, len, inc;
-	Rectangle r=mbb;
+	Rectangle r;
+
+	r = mbb;
+	mbb = NULLMBB;
 
 	if(Dy(r) < 0)
 		return;
 
+	if(r.min.x < 0)
+		r.min.x = 0;
+	if(r.min.y < 0)
+		r.min.y = 0;
+	if(r.max.x > gscreen.r.max.x)
+		r.max.x = gscreen.r.max.x;
+	if(r.max.y > gscreen.r.max.y)
+		r.max.y = gscreen.r.max.y;
+
 	sp = (uchar*)gaddr(&gscreen, r.min);
 	hp = (uchar*)gaddr(&vgascreen, r.min);
 
 	len = (r.max.x * (1<<gscreen.ldepth) + 31)/32
 		- (r.min.x * (1<<gscreen.ldepth))/32;
 	len *= BY2WD;
+	if(len <= 0)
+		return;
 
 	inc = gscreen.width * BY2WD - len;
 
 	for (y = r.min.y; y < r.max.y; y++){
-		for(se = sp + len; sp < se;)
-			*hp++ = cswizzle[*sp++];
-		sp += inc;
-		hp += inc;
+		l0update(sp, hp, len);
+		sp += inc+len;
+		hp += inc+len;
 	}
-	mbb = NULLMBB;
 }
 
 void
diff --git a/port/devbit.c b/port/devbit.c
index af64d272e851ffc03e4bb1f0365f9fca5b46d811..8c5078d3b734ff9e56fb44aa2121a5fe18e8beaa 100644
--- a/port/devbit.c
+++ b/port/devbit.c
@@ -795,7 +795,7 @@ bitwrite(Chan *c, void *va, long n, ulong offset)
 	ulong l, nw, ws, rv, q0, q1;
 	ulong *lp;
 	int off, isoff, i, j, ok;
-	ulong *endscreen = gaddr(&gscreen, Pt(0, gscreen.r.max.y));
+ 	ulong *endscreen = gaddr(&gscreen, Pt(0, gscreen.r.max.y));
 	Point pt, pt1, pt2;
 	Rectangle rect;
 	Cursor curs;
@@ -933,6 +933,18 @@ bitwrite(Chan *c, void *va, long n, ulong offset)
 				p += 1;
 				break;
 			}
+			if(m == 2){
+				if(p[1]){	/* make damn sure */
+					cursor.disable = 0;
+					isoff = 1;
+				}else{
+					cursoroff(1);
+					cursor.disable = 1;
+				}
+				m -= 2;
+				p += 2;
+				break;
+			}
 			if(m < 73)
 				error(Ebadblt);
 			curs.offset.x = BGLONG(p+1);
@@ -1147,7 +1159,7 @@ bitwrite(Chan *c, void *va, long n, ulong offset)
 				isoff = 1;
 			}
 			gsegment(dst, pt1, pt2, t, fc);
-			if(dst->base < endscreen) {
+			if(dst->base < endscreen){
 				mbbpt(pt1);
 				mbbpt(pt2);
 			}
@@ -1574,9 +1586,9 @@ bitwrite(Chan *c, void *va, long n, ulong offset)
 		}
 
 	poperror();
+	screenupdate();
 	if(isoff)
 		cursoron(1);
-	screenupdate();
 	qunlock(&bit);
 	return n;
 }
@@ -1917,6 +1929,8 @@ Cursortocursor(Cursor *c)
 void
 cursoron(int dolock)
 {
+	if(cursor.disable)
+		return;
 	if(dolock)
 		lock(&cursor);
 	if(cursor.visible++ == 0){
@@ -1929,6 +1943,7 @@ cursoron(int dolock)
 		gbitblt(&gscreen, cursor.r.min,
 			&set, Rect(0, 0, 16, 16), flipping? flipD[S|D] : S|D);
 		mbbrect(cursor.r);
+		screenupdate();
 	}
 	if(dolock)
 		unlock(&cursor);
@@ -1937,11 +1952,14 @@ cursoron(int dolock)
 void
 cursoroff(int dolock)
 {
+	if(cursor.disable)
+		return;
 	if(dolock)
 		lock(&cursor);
 	if(--cursor.visible == 0) {
 		gbitblt(&gscreen, cursor.r.min, &cursorback, Rect(0, 0, 16, 16), S);
 		mbbrect(cursor.r);
+		screenupdate();
 	}
 	if(dolock)
 		unlock(&cursor);
@@ -2068,7 +2086,7 @@ mouseputc(IOQ *q, int c)
 	if(c & 0x80)
 		msg[nb] |= ~0xFF;	/* sign extend */
 	if(++nb == 5){
-		mouse.newbuttons = b[((msg[0]&7)^7) | (mouseshifted ? 2 : 0)];
+		mouse.newbuttons = b[((msg[0]&7)^7) | (mouseshifted ? 8 : 0)];
 		mouse.dx = msg[1]+msg[3];
 		mouse.dy = -(msg[2]+msg[4]);
 		mouse.track = 1;
diff --git a/port/devenv.c b/port/devenv.c
index dffe3b039b052d0a9e2d66f29014e8ed18e3c9c6..462d1c43645fcf2903c9d9e074c29f387cd56137 100644
--- a/port/devenv.c
+++ b/port/devenv.c
@@ -264,10 +264,13 @@ void
 envcpy(Egrp *to, Egrp *from)
 {
 	Evalue **l, *ne, *e;
+	char *p;
 
 	l = &to->entries;
 	qlock(from);
 	for(e = from->entries; e; e = e->link) {
+if(e->name == 0) panic("e->name == 0");
+for(p = e->name; *p; p++) if(p - e->name >= NAMELEN) panic("e->name %.*s", NAMELEN, e->name);
 		ne = smalloc(sizeof(Evalue));
 		ne->name = smalloc(strlen(e->name)+1);
 		strcpy(ne->name, e->name);
diff --git a/ss/screen.h b/ss/screen.h
index 04fd048b804c96347861a49ecae322422183ad7f..f7c92d1c1306c0819fc85c7ab4006538f645beea 100644
--- a/ss/screen.h
+++ b/ss/screen.h
@@ -19,6 +19,7 @@ struct Cursorinfo{
 	Cursor;
 	Lock;
 	int	visible;	/* on screen */
+	int	disable;	/* from being used */
 	Rectangle r;		/* location */
 };