From f4d01f06552c1590353b20cd73512961f4a7c9f0 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 17 Aug 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-08-17

---
 port/sysfile.c |  7 +++++--
 ss/main.c      |  2 ++
 ss/screen.c    | 39 ++++++++++++++++++++++++---------------
 3 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/port/sysfile.c b/port/sysfile.c
index 46dd443a12ae3e2c047800d3b905df7e6b7c4670..099502b6edcff9c5abc2d0f2035959369e37b9b7 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -165,6 +165,11 @@ fdclose(int fd, int flag)
 
 	lock(f);
 	c = f->fd[fd];
+	if(c == 0){
+		/* can happen for users with shared fd tables */
+		unlock(f);
+		return;
+	}
 	if(flag){
 		if(c==0 || !(c->flag&flag)){
 			unlock(f);
@@ -177,8 +182,6 @@ fdclose(int fd, int flag)
 			f->maxfd = i;
 
 	unlock(f);
-	if(c == 0)
-		panic("fdclose");
 	close(c);
 }
 
diff --git a/ss/main.c b/ss/main.c
index 9bfd1ed278c5a830909f9811645ed92b1eb11f58..037984abb832a98ceecb9f2a3702b1eb4a1200cb 100644
--- a/ss/main.c
+++ b/ss/main.c
@@ -141,6 +141,8 @@ init0(void)
 	print("frame buffer id %lux %s\n", conf.monitor, fbstr);
 	print("NKLUDGE %d\n", NKLUDGE);
 
+mapdump();
+
 	u->slash = (*devtab[0].attach)(0);
 	u->dot = clone(u->slash, 0);
 
diff --git a/ss/screen.c b/ss/screen.c
index 8171ad867d6f3fd33a93af5a1ba2613f5c30bf23..2f96b11045c82921e67108829e3c2e16b7fbe4c5 100644
--- a/ss/screen.c
+++ b/ss/screen.c
@@ -27,13 +27,13 @@ void		(*kprofp)(ulong);
 typedef struct	DAC DAC;
 struct DAC
 {
-	uchar	addr;	/* DAC address register */
+	uchar	addr;		/* address register */
 	uchar	pad0[3];
-	uchar	color;	/* DAC color palette */
+	uchar	color;		/* color palette */
 	uchar	pad1[3];
-	uchar	cntrl;	/* DAC control register */
+	uchar	cntrl;		/* control register */
 	uchar	pad2[3];
-	uchar	ovrl;	/* DAC overlay palette */
+	uchar	ovrl;		/* overlay palette */
 	uchar	pad3[3];
 }*dac;
 
@@ -90,6 +90,14 @@ screeninit(char *str)
 	out.bwid = defont0.info[' '].width;
 	dac = (DAC*)(kmappa(FRAMEBUF+s->dacaddr, PTENOCACHE|PTEIO)->va);
 	if(gscreen.ldepth == 3){
+		dac->addr = 4;
+		dac->cntrl = 0xFF;	/* enable all planes */
+		dac->addr = 5;
+		dac->cntrl = 0x00;	/* no blinking */
+		dac->addr = 6;
+		dac->cntrl = 0x43;	/* enable palette ram and display */
+		dac->addr = 7;
+		dac->cntrl = 0x00;	/* no tests */
 		havecol = 0;	
 		if(havecol) {
 			/*
@@ -108,17 +116,6 @@ screeninit(char *str)
 			setcolor(85, 0xAAAAAAAA, 0xAAAAAAAA, 0xAAAAAAAA);
 			setcolor(170, 0x55555555, 0x55555555, 0x55555555);
 		} else {
-/*
-			dac->addr = 4;
-			dac->cntrl = 0xFF;
-			dac->addr = 5;
-			dac->cntrl = 0x00;
-			dac->addr = 6;
-			dac->cntrl = 0x40;
-			dac->addr = 7;
-			dac->cntrl = 0x00;
-*/
-
 			dac->addr = 0;
 			for(i=255; i>=0; i--){
 				dac->color = i;
@@ -129,6 +126,18 @@ screeninit(char *str)
 	}
 }
 
+mapdump(void)
+{
+	dac->addr = 4;
+	print("cntrl4 %.2ux\n", dac->cntrl);
+	dac->addr = 5;
+	print("cntrl5 %.2ux\n", dac->cntrl);
+	dac->addr = 6;
+	print("cntrl6 %.2ux\n", dac->cntrl);
+	dac->addr = 7;
+	print("cntrl7 %.2ux\n", dac->cntrl);
+}
+
 void
 screenputnl(void)
 {