From 4fa1a84123c6c5454cd920511aa28dbad21f7b16 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 11 Jun 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-06-11

---
 carrera/fptrap.c | 12 +++++++-----
 carrera/l.s      |  2 +-
 carrera/mem.h    |  1 -
 carrera/trap.c   | 23 +++++++++++++++++++++--
 port/portfns.h   |  1 +
 port/sysfile.c   |  7 ++++++-
 6 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/carrera/fptrap.c b/carrera/fptrap.c
index 2b8457ebeafcf67a422adfdf8760baaa7f3dcf25..d41ab97228d0ccd1161d0337087b034c0dab7cff 100644
--- a/carrera/fptrap.c
+++ b/carrera/fptrap.c
@@ -174,17 +174,19 @@ fpunimp(ulong iw)
 	return 0;
 }
 
-static uvlong*
+static ulong*
 reg(Ureg *ur, int regno)
 {
 	/* regs go from R31 down in ureg, R29 is missing */
-	if(regno == 31)
+	switch(regno) {
+	case 31:
 		return &ur->r31;
-	if(regno == 30)
+	case 30:
 		return &ur->r30;
-	if(regno == 29)
+	case 29:
 		return &ur->sp;
-	return (&ur->r28) + (28-regno);
+	}
+	return (&ur->r28) + (28-regno)*(&ur->r27-&ur->r28);
 }
 
 static ulong
diff --git a/carrera/l.s b/carrera/l.s
index 28d6bf92568f8795369cbc64a724ff2256fecd61..7d56a4b510141c2d61355aedeb86a163892f9696 100644
--- a/carrera/l.s
+++ b/carrera/l.s
@@ -93,7 +93,7 @@ TEXT	touser(SB), $-4
 	MOVW	M(STATUS), R4
 	WAIT
 	AND	$(~KMODEMASK), R4
-	OR	$(KUSER|EXL|IE|UX), R4
+	OR	$(KUSER|EXL|IE), R4
 	MOVW	R4, M(STATUS)
 	WAIT
 	MOVW	R1, SP
diff --git a/carrera/mem.h b/carrera/mem.h
index e8d57bda03e4530a8b5a9a9e3865458fbfa7a894..b5b062b4c672e6aee21e420720958bcf82206555 100644
--- a/carrera/mem.h
+++ b/carrera/mem.h
@@ -66,7 +66,6 @@
 #define ERL		0x00000004
 #define KSUPER		0x00000008
 #define KUSER		0x00000010
-#define UX		0x00000020
 #define INTMASK		0x0000ff00
 #define INTR0		0x00000100
 #define INTR1		0x00000200
diff --git a/carrera/trap.c b/carrera/trap.c
index b9d20067c6d9089afa216e9521018719914d20f9..ce57dd6a073e1e52bb3c4f7f3411672fff04a3fc 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -283,6 +283,14 @@ trap(Ureg *ur)
 	}
 }
 
+struct
+{
+	ulong cause;
+	ulong devint3;
+	ulong devint4;
+	ulong state;
+}sisr;
+
 void
 intr(Ureg *ur)
 {
@@ -292,9 +300,11 @@ intr(Ureg *ur)
 
 	m->intr++;
 	cause &= INTR7|INTR6|INTR5|INTR4|INTR3|INTR2|INTR1|INTR0;
-
+sisr.cause = cause;
 	if(cause & INTR3) {
 		devint = IO(uchar, Intcause);
+sisr.devint3 = devint;
+sisr.state = 0;
 		switch(devint) {
 		default:
 			panic("unknown devint=#%lux", devint);
@@ -318,9 +328,11 @@ intr(Ureg *ur)
 			break;
 		}
 		cause &= ~INTR3;
+sisr.state = 1;
 	}
 
 	if(cause & INTR2) {
+sisr.state = 2;
 		isr = IO(ulong, R4030Isr);
 		if(isr) {
 			iprint("R4030 Interrupt\n");
@@ -330,12 +342,14 @@ intr(Ureg *ur)
 			iprint(" MFA #%lux\n", IO(ulong, R4030Mfa));
 		}
 		cause &= ~INTR2;
+sisr.state = 3;
 	}
 
 	if(cause & INTR4) {
 		devint = IO(uchar, I386ack);
 		vec = devint&~0x7;
-
+sisr.devint4 = devint;
+sisr.state = 4;
 		/* reenable the 8259 interrupt */
 		if(vec == Int0vec || vec == Int1vec){
 			EISAOUTB(Int0ctl, EOI);
@@ -348,13 +362,18 @@ intr(Ureg *ur)
 			iprint("i386ACK #%lux\n", devint);
 			break;
 		case 7:
+sisr.state = 5;
 			audiosbintr();
+sisr.state = 6;
 			break;
 		case 13:
+sisr.state = 7;
 			audiodmaintr();
+sisr.state = 8;
 			break;
 		}
 		cause &= ~INTR4;
+sisr.state = 9;
 	}
 
 	if(cause & INTR7) {
diff --git a/port/portfns.h b/port/portfns.h
index f7fca4e44eaec9a5667dcccfae0916696f5c6aac..770e595dd1dbd242f5e7361c20ac0644399f65d0 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -244,6 +244,7 @@ void		uncachepage(Page*);
 long		unionread(Chan*, void*, long);
 void		unlock(Lock*);
 void		unmount(Chan*, Chan*);
+Chan*		undomount(Chan*);
 void		userinit(void);
 ulong		userpc(void);
 long		userwrite(char*, int);
diff --git a/port/sysfile.c b/port/sysfile.c
index b0fc1fb44cbc929264c6f861a813454d5da78832..e4bda348c4940892b405e96f207c7a49fce0e98f 100644
--- a/port/sysfile.c
+++ b/port/sysfile.c
@@ -94,7 +94,12 @@ sysfd2path(ulong *arg)
 		error(Ebadarg);
 
 	c = fdtochan(arg[0], -1, 0, 0);
-
+	/* If we used open the chan will be at the first element
+	 * of a union rather than the mhead of the union. undomount
+	 * will make it look like we used Atodir rather than Aopen.
+	 */
+	if(c->qid.path & CHDIR)
+		c = undomount(c);
 	ptpath(c->path, (char*)arg[1], arg[2]);
 	return 0;
 }