From d58cfd17b00a5f5d9d8df46dccb720f469165593 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 29 Apr 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-04-29

---
 pc/devhard.c | 21 +++++++++++++++++++--
 pc/fns.h     |  2 ++
 pc/main.c    |  7 ++++---
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/pc/devhard.c b/pc/devhard.c
index 8116c65b9ede31ad07253df418944ad9d27baf07..56a5b560a721a1cbc7520248a320568c6e63019f 100644
--- a/pc/devhard.c
+++ b/pc/devhard.c
@@ -35,6 +35,7 @@ enum
 	Cread=		0x20,
 	Cwrite=		0x30,
 	Cident=		0xEC,
+	Cident2=	0xFF,	/* pseudo command for post Cident interrupt */
 	Csetbuf=	0xEF,
 
 	/* file types */
@@ -587,7 +588,16 @@ hardident(Drive *dp)
 		error(Eio);
 	}
 	memmove(&dp->id, cp->buf, dp->bytes);
-
+	/*
+	 * this function appears to respond with an extra interrupt after
+	 * the indent information is read, except on the safari.  The following
+	 * delay gives this extra interrupt a chance to happen while we are quiet.
+	 * Otherwise, the interrupt may come during a subsequent read or write,
+	 * causing a panic and much confusion.
+	 */
+	if (cp->cmd == Cident2)
+		tsleep(&cp->r, return0, 0, 10);
+	cp->cmd = 0;
 	poperror();
 	qunlock(cp);
 }
@@ -735,7 +745,10 @@ hardintr(Ureg *ur)
 		cp->sofar++;
 		if(cp->sofar >= cp->nsecs){
 			cp->lastcmd = cp->cmd;
-			cp->cmd = 0;
+			if (cp->cmd == Cread)
+				cp->cmd = 0;
+			else
+				cp->cmd = Cident2;
 			wakeup(&cp->r);
 		}
 		break;
@@ -744,6 +757,10 @@ hardintr(Ureg *ur)
 		cp->cmd = 0;
 		wakeup(&cp->r);
 		break;
+	case Cident2:
+		cp->lastcmd = cp->cmd;
+		cp->cmd = 0;
+		break;
 	case 0:
 		print("interrupt cmd=0, lastcmd=%02x status=%02x\n",
 			cp->lastcmd, cp->status);
diff --git a/pc/fns.h b/pc/fns.h
index 598720c59171c5b8af415782abcbba750d5c7706..e975ede15494fc8b6fee781a7064224cfb894378 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -7,6 +7,7 @@ void	bootargs(ulong);
 void	clock(Ureg*);
 void	clockinit(void);
 void	config(int);
+void	confinit1(void);
 int	cpuspeed(int);
 void	delay(int);
 void	dmaend(int);
@@ -32,6 +33,7 @@ void	idle(void);
 int	inb(int);
 void	inss(int, void*, int);
 void	kbdinit(void);
+void	ksetpcinfo(void);
 void	mathinit(void);
 void	mmuinit(void);
 int	modem(int);
diff --git a/pc/main.c b/pc/main.c
index a95c1276713be6efdca8337b74cb1c3b9b0a4084..c1bfe00fca22a92985dccdd0602e56a8d523aafb 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -89,7 +89,7 @@ init0(void)
 	chandevinit();
 
 	if(!waserror()){
-		ksetterm("at&t %s");
+		ksetpcinfo();
 		ksetenv("cputype", "386");
 		poperror();
 	}
@@ -206,7 +206,7 @@ confinit(void)
 	/*
 	 *  the first 640k is the standard useful memory
 	 *  the next 128K is the display
-	 *  the last 256k belongs to the roms
+	 *  the last 256k belongs to the roms and other devices
 	 */
 	conf.npage0 = 640/4;
 	conf.base0 = 0;
@@ -275,9 +275,10 @@ confinit(void)
 	conf.arp = 32;
 	conf.frag = 32;
 	conf.cntrlp = 0;
-	conf.nfloppy = 1;
+	conf.nfloppy = 2;
 	conf.nhard = 1;
 	conf.dkif = 1;
+	confinit1();
 }
 
 char *mathmsg[] =