From a6a12fae6f5fc4f8e7870d110544ec7ae096b23e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 8 May 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-05-08

---
 power/dat.h       | 1 +
 power/devhotrod.c | 3 +++
 power/faultmips.c | 4 ++++
 power/io.h        | 8 ++++++++
 power/trap.c      | 2 ++
 5 files changed, 18 insertions(+)

diff --git a/power/dat.h b/power/dat.h
index 4908199c43bc16f15c3bfda1cf28f61a6ea0ad80..7a6d30b9c6c234f07d2877793dbedb43f686539b 100644
--- a/power/dat.h
+++ b/power/dat.h
@@ -144,6 +144,7 @@ struct Mach
 	int	syscall;
 	int	load;
 	int	intr;
+	int	ledval;			/* value last written to LED */
 
 	int	stack[1];
 };
diff --git a/power/devhotrod.c b/power/devhotrod.c
index 61ca1af5b73c982ffd392cb4ed9809e38005ace1..5ad01f52638f9704c023adafa41ef3c46332aa6a 100644
--- a/power/devhotrod.c
+++ b/power/devhotrod.c
@@ -412,9 +412,11 @@ hotrodintr(int vec)
 	Hotmsg *hm;
 	ulong l;
 
+	LEDON(LEDhotintr);
 	h = &hotrod[vec - Vmevec];
 	if(h<hotrod || h>&hotrod[Nhotrod]){
 		print("bad hotrod vec\n");
+		LEDOFF(LEDhotintr);
 		return;
 	}
 	while(l = h->addr->replyq[h->ri]){	/* assign = */
@@ -427,4 +429,5 @@ hotrodintr(int vec)
 		if(!hm->abort)
 			wakeup(&hm->r);
 	}
+	LEDOFF(LEDhotintr);
 }
diff --git a/power/faultmips.c b/power/faultmips.c
index 32ea727c4ba615706afd92588b078f955815bb29..66520d1214e6b538835ae1a182a623a2adaf1e90 100644
--- a/power/faultmips.c
+++ b/power/faultmips.c
@@ -5,6 +5,7 @@
 #include	"fns.h"
 #include	"ureg.h"
 #include	"../port/error.h"
+#include	"io.h"
 
 /*
  *  find out fault address and type of access.
@@ -18,6 +19,7 @@ faultmips(Ureg *ur, int user, int code)
 	char buf[ERRLEN];
 	int read;
 
+	LEDON(LEDfault);
 	addr = ur->badvaddr;
 	addr &= ~(BY2PG-1);
 	read = !(code==CTLBM || code==CTLBS);
@@ -27,6 +29,7 @@ faultmips(Ureg *ur, int user, int code)
 			sprint(buf, "sys: trap: fault %s addr=0x%lux",
 				read? "read" : "write", ur->badvaddr);
 			postnote(u->p, 1, buf, NDebug);
+			LEDOFF(LEDfault);
 			return;
 		}
 		print("kernel %s badvaddr=0x%lux\n", excname[code], ur->badvaddr);
@@ -34,6 +37,7 @@ faultmips(Ureg *ur, int user, int code)
 		dumpregs(ur);
 		panic("fault");
 	}
+	LEDOFF(LEDfault);
 }
 
 /*
diff --git a/power/io.h b/power/io.h
index f1a7c29eb7e5455ed39b61caaaa5d0feeda86bee..0d14f813790b44b8c9e456e478bdbb747498d492 100644
--- a/power/io.h
+++ b/power/io.h
@@ -7,6 +7,14 @@
 #define	SBSEMTOP	SYNCBUS(ulong, 0x400000)
 
 #define	LED		((char*)0xBF200001)
+enum
+{
+	LEDhotintr=	1<<0,
+	LEDclock=	1<<1,
+	LEDfault=	1<<2,
+};
+#define LEDON(x) { m->ledval |= x; *LED = m->ledval; }
+#define LEDOFF(x) { m->ledval &= ~x; *LED = m->ledval; }
 
 typedef struct SBCC	SBCC;
 typedef struct Timer	Timer;
diff --git a/power/trap.c b/power/trap.c
index d16cda65cdb04d965b3da3ae60f874b8e4bed5b1..b3c91898191f4baf82b441e2dd75eb9f7cb499a0 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -190,7 +190,9 @@ intr(Ureg *ur)
 	m->intr++;
 	cause = ur->cause&(INTR5|INTR4|INTR3|INTR2|INTR1);
 	if(cause & (INTR2|INTR4)){
+		LEDON(LEDclock);
 		clock(ur);
+		LEDOFF(LEDclock);
 		cause &= ~(INTR2|INTR4);
 	}
 	if(cause & INTR1){