--- /sys/src/9/port/fault.c	Thu Jun 13 23:04:13 2013
+++ /sys/src/9/port/fault.c	Mon Jun 24 22:28:37 2013
@@ -8,7 +8,6 @@
 int
 fault(ulong addr, int read)
 {
-	int tries;
 	Segment *s;
 	char *sps;
 
@@ -22,7 +21,7 @@
 	spllo();
 
 	m->pfault++;
-	for(tries = 200; tries > 0; tries--) {
+	for(;;) {
 		s = seg(up, addr, 1);		/* leaves s->lk qlocked if seg != nil */
 		if(s == 0) {
 			up->psstate = sps;
@@ -38,13 +37,6 @@
 		if(fixfault(s, addr, read, 1) == 0)	/* qunlocks s->lk */
 			break;
 	}
-	/*
-	 * if we loop more than a few times, we're probably stuck on
-	 * an unfixable address, almost certainly due to a bug
-	 * elsewhere, so there's no point in spinning forever.
-	 */
-	if (tries <= 0)
-		panic("fault: fault stuck on va %#8.8p read %d\n", addr, read);
 
 	up->psstate = sps;
 	return 0;
--- /sys/src/cmd/8l/elf.h	Fri Mar 22 05:02:18 2013
+++ /sys/src/cmd/8l/elf.h	Thu Jun 27 00:34:09 2013
@@ -45,6 +45,7 @@
 	I860 = 7,		/* Intel i860 */
 	MIPS = 8,		/* Mips R2000 */
 	S370 = 9,		/* Amdhal	*/
+	MIPSR4K = 10,		/* Mips R4000 */
 	SPARC64 = 18,		/* Sun SPARC v9 */
 	POWER = 20,		/* PowerPC */
 	POWER64 = 21,		/* PowerPC64 */
--- /sys/src/cmd/file.c	Wed Apr 24 01:06:27 2013
+++ /sys/src/cmd/file.c	Thu Jun 27 00:33:52 2013
@@ -1456,7 +1456,7 @@
 
 			if(n>0 && n < nelem(type) && type[n])
 				t = type[n];
-			print("%s ELF %s\n", p, t);
+			print("%s ELF%s %s\n", p, (buf[4] == 2? "64": "32"), t);
 		}
 		else
 			print("application/x-elf-executable");
--- /sys/src/cmd/ip/ipconfig/main.c	Sat Jul 24 00:51:30 2010
+++ /sys/src/cmd/ip/ipconfig/main.c	Tue Jun 25 00:35:14 2013
@@ -1156,6 +1156,10 @@
 			DEBUG("dhcprecv: read timed out");
 		return;
 	}
+	if(n == 0){
+		warning("dhcprecv: zero-length packet read");
+		return;
+	}
 
 	bp = parsebootp(buf, n);
 	if(bp == 0) {
@@ -1608,7 +1612,8 @@
 
 	bp = (Bootp*)p;
 	if(n < bp->optmagic - p) {
-		warning("parsebootp: short bootp packet");
+		warning("parsebootp: short bootp packet; with options, "
+			"need %d bytes, got %d", bp->optmagic - p, n);
 		return nil;
 	}
 
--- /sys/src/cmd/vl/noop.c	Sun Jun 23 06:46:35 2013
+++ /sys/src/cmd/vl/noop.c	Tue Jun 25 00:34:29 2013
@@ -3,7 +3,8 @@
 /*
  * flag: insert nops to prevent three consecutive stores.
  * workaround for 24k erratum #48, costs about 10% in text space,
- * so only enable this if you need it.  a test case is "hoc -e '7^6'".
+ * so only enable this if you need it.  test cases are "hoc -e '7^6'"
+ * and "{ echo moon; echo plot } | scat".
  */
 enum {
 	Mips24k	= 0,
@@ -111,6 +112,13 @@
 	return 0;
 }
 
+static void
+nopafter(Prog *p)
+{
+	p->mark |= LABEL|SYNC;
+	addnop(p);
+}
+
 /*
  * workaround for 24k erratum #48, costs about 0.5% in space.
  * inserts a NOP before the last of 3 consecutive stores.
@@ -127,15 +135,13 @@
 	if(!isstore(p1))
 		return 0;
 	if(isdblwrdmov(p) || isdblwrdmov(p1)) {
-		p->mark |= LABEL|SYNC;
-		addnop(p);
+		nopafter(p);
 		nop.store.count++;
 		nop.store.outof++;
 		return 1;
 	}
 	if(isstore(p1->link)) {
-		p1->mark |= LABEL|SYNC;
-		addnop(p1);
+		nopafter(p1);
 		nop.store.count++;
 		nop.store.outof++;
 		return 1;
@@ -155,21 +161,48 @@
 
 	for(p = firstp; p != P; p = p->link)
 		if(isstore(p))
-			p->mark |= NOSCHED; /* keep stores out of delay slots */
+			p->mark |= NOSCHED;
 }
 
-void
+int
 triplestorenops(void)
 {
+	int r;
 	Prog *p, *p1;
 
+	r = 0;
 	for(p = firstp; p != P; p = p1) {
 		p1 = p->link;
 //		if (p->mark & NOSCHED)
 //			continue;
-		if(ismove(p))
-			no3stores(p);
-		else if (isbranch(p))
+		if(ismove(p) && isstore(p)) {
+			if (no3stores(p))
+				r++;
+			/*
+			 * given storenosched, the next two
+			 * checks shouldn't be necessary.
+			 */
+			/*
+			 * add nop after first MOV in `MOV; Bcond; MOV'.
+			 */
+			else if(isbranch(p1) && isstore(p1->link)) {
+				nopafter(p);
+				nop.branch.count++;
+				nop.branch.outof++;
+				r++;
+			}
+			/*
+			 * this may be a branch target, so insert a nop after,
+			 * in case a branch leading here has a store in its
+			 * delay slot and we have consecutive stores here.
+			 */
+			if(p->mark & (LABEL|SYNC) && !isnop(p1)) {
+				nopafter(p);
+				nop.branch.count++;
+				nop.branch.outof++;
+				r++;
+			}
+		} else if (isbranch(p))
 			/*
 			 * can't ignore delay slot of a conditional branch;
 			 * the branch could fail and fall through.
@@ -177,6 +210,7 @@
 			if (!iscondbranch(p) && p1)
 				p1 = p1->link;	/* skip its delay slot */
 	}
+	return r;
 }
 
 void
--- /sys/src/libmach/elf.h	Wed Jul 18 02:17:55 2012
+++ /sys/src/libmach/elf.h	Thu Jun 27 00:35:28 2013
@@ -119,6 +119,7 @@
 	I860 = 7,		/* Intel i860 */
 	MIPS = 8,		/* Mips R2000 */
 	S370 = 9,		/* Amdhal	*/
+	MIPSR4K = 10,		/* Mips R4000 */
 	SPARC64 = 18,		/* Sun SPARC v9 */
 	POWER = 20,		/* PowerPC */
 	POWER64 = 21,		/* PowerPC64 */