Index: sys/arch/arm/arm/db_trace.c
===================================================================
RCS file: /cvsroot/src/sys/arch/arm/arm/db_trace.c,v
retrieving revision 1.27
diff -u -p -u -r1.27 db_trace.c
--- sys/arch/arm/arm/db_trace.c	31 Dec 2012 08:57:27 -0000	1.27
+++ sys/arch/arm/arm/db_trace.c	18 Jan 2013 07:14:36 -0000
@@ -91,6 +91,7 @@ db_stack_trace_print(db_expr_t addr, boo
 	char c;
 	bool		kernel_only = true;
 	bool		trace_thread = false;
+	bool		trace_regs = false;
 	bool		lwpaddr = false;
 	db_addr_t	scp, pc;
 	int		scp_offset;
@@ -104,6 +105,8 @@ db_stack_trace_print(db_expr_t addr, boo
 			kernel_only = false;
 		if (c == 't')
 			trace_thread = true;
+		if (c == 'r')
+			trace_regs = true;
 	}
 
 	if (!have_addr)
@@ -181,19 +184,22 @@ db_stack_trace_print(db_expr_t addr, boo
 		    (char *)frameb);
 		frame = frameb + 3;
 #endif
-
 		db_printsym(pc, DB_STGY_PROC, pr);
-		(*pr)("\n\t");
+		if (trace_regs) {
+			(*pr)("\n\t");
 #ifdef __PROG26
-		(*pr)("pc =0x%08x rlv=0x%08x (", pc, frame[FR_RLV] & R15_PC);
-		db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC, pr);
-		(*pr)(")\n");
-#else
-		(*pr)("pc =0x%08x rlv=0x%08x (", pc, frame[FR_RLV]);
-		db_printsym(frame[FR_RLV], DB_STGY_PROC, pr);
-		(*pr)(")\n");
+			(*pr)("pc =0x%08x rlv=0x%08x (", pc,
+			     frame[FR_RLV] & R15_PC);
+			db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC, pr);
+			(*pr)(")\n");
+#else
+			(*pr)("pc =0x%08x rlv=0x%08x (", pc, frame[FR_RLV]);
+			db_printsym(frame[FR_RLV], DB_STGY_PROC, pr);
+			(*pr)(")\n");
 #endif
-		(*pr)("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP], frame[FR_RFP]);
+			(*pr)("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP],
+			     frame[FR_RFP]);
+		}
 
 #ifndef _KERNEL
 		db_read_bytes((db_addr_t)((uint32_t *)scp + scp_offset),
@@ -205,7 +211,8 @@ db_stack_trace_print(db_expr_t addr, boo
 			savecode = 0;
 		}
 #endif
-		if ((savecode & 0x0e100000) == 0x08000000) {
+		if (trace_regs &&
+		    (savecode & 0x0e100000) == 0x08000000) {
 			/* Looks like an STM */
 			rp = frame - 4;
 			sep = "\n\t";