From 500ba80012a0d37e86eff1cabfc1b01bbb5b510a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 30 Sep 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-09-30

---
 carrera/main.c   |  2 +-
 carrera/mem.h    |  1 +
 carrera/screen.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++--
 carrera/trap.c   |  1 +
 port/segment.c   |  2 +-
 5 files changed, 81 insertions(+), 5 deletions(-)

diff --git a/carrera/main.c b/carrera/main.c
index c6b6e2d367f2108d921f92df3120660a579a3e9b..2ba7ed9bb8210720286277e60632e4891f14b60f 100644
--- a/carrera/main.c
+++ b/carrera/main.c
@@ -277,7 +277,7 @@ init0(void)
 
 	if(!waserror()){
 		ksetenv("cputype", "mips");
-		sprint(buf, "sgi %s 4D", conffile);
+		sprint(buf, "%s R4400PC", conffile);
 		ksetenv("terminal", buf);
 		ksetenv("sysname", sysname);
 		poperror();
diff --git a/carrera/mem.h b/carrera/mem.h
index cf9dfea53382b725d95515835456611e5c56ab07..53db6f31d5577a37e4913f9f43c446a5dad6d992 100644
--- a/carrera/mem.h
+++ b/carrera/mem.h
@@ -75,6 +75,7 @@
 #define INTR7		0x00008000
 #define ISC		0x00010000
 #define SWC		0x00020000
+#define CU0		0x10000000
 #define CU1		0x20000000
 
 /*
diff --git a/carrera/screen.c b/carrera/screen.c
index 568c1f4716a81c63599958a139a28fdff6344207..5101ad5e82a87cf4d49d1425c2940952c416bb0d 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -253,6 +253,7 @@ screenputc(char *buf)
 {
 	int pos;
 
+	mbbpt(cursor);
 	switch(buf[0]) {
 	case '\n':
 		if(cursor.y+h >= window.max.y)
@@ -278,6 +279,7 @@ screenputc(char *buf)
 
 		cursor = gsubfstring(&gscreen, cursor, &defont0, buf, S);
 	}
+	mbbpt(Pt(cursor.x, cursor.y+h));
 }
 
 void
@@ -295,7 +297,6 @@ screenputs(char *s, int n)
 	else
 		lock(&screenlock);
 
-	mbbpt(cursor);
 	while(n > 0) {
 		i = chartorune(&r, s);
 		if(i == 0){
@@ -313,8 +314,6 @@ screenputs(char *s, int n)
 		mbb = window;
 		isscroll = 0;
 	}
-	else
-		mbbpt(Pt(cursor.x, cursor.y+h));
 
 	screenupdate();
 	unlock(&screenlock);
@@ -549,3 +548,78 @@ screenupdate(void)
 		sp += inc;
 	}
 }
+
+/*
+ * graphics
+ */
+void
+screenload(Rectangle r, uchar *data, long n)
+{
+	int y, ws, l, t, lpart, rpart, mx, m, mr;
+	uchar *q;
+
+	if(!rectclip(&r, gscreen.r))
+		return;
+	lock(&screenlock);
+	ws = 8>>gscreen.ldepth;	/* pixels per byte */
+	/* set l to number of bytes of data per scan line */
+	if(r.min.x >= 0)
+		l = (r.max.x+ws-1)/ws - r.min.x/ws;
+	else{		/* make positive before divide */
+		t = (-r.min.x)+ws-1;
+		t = (t/ws)*ws;
+		l = (t+r.max.x+ws-1)/ws;
+	}
+	if(n != l*Dy(r)){
+		unlock(&screenlock);
+		error("bad tile size");
+	}
+	q = gbaddr(&gscreen, r.min);
+	mx = 7>>gscreen.ldepth;
+	lpart = (r.min.x & mx) << gscreen.ldepth;
+	rpart = (r.max.x & mx) << gscreen.ldepth;
+	m = 0xFF >> lpart;
+	mr = 0xFF ^ (0xFF >> rpart);
+	/* may need to do bit insertion on edges */
+	if(l == 1){	/* all in one byte */
+		if(rpart)
+			m ^= 0xFF >> rpart;
+		for(y=r.min.y; y<r.max.y; y++){
+			*q ^= (*data^*q) & m;
+			q += gscreen.width*sizeof(ulong);
+			data++;
+		}
+	}else if(lpart==0 && rpart==0){	/* easy case */
+		for(y=r.min.y; y<r.max.y; y++){
+			memmove(q, data, l);
+			q += gscreen.width*sizeof(ulong);
+			data += l;
+		}
+	}else if(rpart==0){
+		for(y=r.min.y; y<r.max.y; y++){
+			*q ^= (*data^*q) & m;
+			if(l > 1)
+				memmove(q+1, data+1, l-1);
+			q += gscreen.width*sizeof(ulong);
+			data += l;
+		}
+	}else if(lpart == 0){
+		for(y=r.min.y; y<r.max.y; y++){
+			if(l > 1)
+				memmove(q, data, l-1);
+			q[l-1] ^= (data[l-1]^q[l-1]) & mr;
+			q += gscreen.width*sizeof(ulong);
+			data += l;
+		}
+	}else for(y=r.min.y; y<r.max.y; y++){
+			*q ^= (*data^*q) & m;
+			if(l > 2)
+				memmove(q+1, data+1, l-2);
+			q[l-1] ^= (data[l-1]^q[l-1]) & mr;
+			q += gscreen.width*sizeof(ulong);
+			data += l;
+		}
+	mbbrect(r);
+	screenupdate();
+	unlock(&screenlock);
+}
diff --git a/carrera/trap.c b/carrera/trap.c
index 335a7f7e87e2282eac511d958bc50712141f7477..d6a2bcb23131c318b6df9a8738068d0d429267aa 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -613,6 +613,7 @@ forkchild(Proc *p, Ureg *ur)
 	memmove(cur, ur, sizeof(Ureg));
 
 	cur->pc += 4;
+	cur->status |= CU0;
 
 	/* Things from bottom of syscall we never got to execute */
 	p->psstate = 0;
diff --git a/port/segment.c b/port/segment.c
index fa922ba21e6fffcb5191c5b6bd7927b362a0d5b0..2de99627f7208b9f88ba61c32009a375854200f8 100644
--- a/port/segment.c
+++ b/port/segment.c
@@ -485,7 +485,7 @@ syssegflush(ulong *arg)
 	len = arg[1];
 
 	while(len > 0) {
-		s = seg(u->p, addr, 1);
+		s = seg(up, addr, 1);
 		if(s == 0)
 			error(Ebadarg);