diff --git a/sys/alpha/alpha/gdb_machdep.c b/sys/alpha/alpha/gdb_machdep.c
index cbc38a8a9caf..a701c6f0749e 100644
--- a/sys/alpha/alpha/gdb_machdep.c
+++ b/sys/alpha/alpha/gdb_machdep.c
@@ -59,7 +59,7 @@ gdb_cpu_getreg(int regnum, size_t *regsz)
 }
 
 void
-gdb_cpu_setreg(int regnum, register_t val)
+gdb_cpu_setreg(int regnum, void *val)
 {
 	switch (regnum) {
 	}
diff --git a/sys/alpha/include/gdb_machdep.h b/sys/alpha/include/gdb_machdep.h
index 5ca5d69f5890..c404c739efb1 100644
--- a/sys/alpha/include/gdb_machdep.h
+++ b/sys/alpha/include/gdb_machdep.h
@@ -46,7 +46,7 @@ gdb_cpu_query(void)
 }
 
 void *gdb_cpu_getreg(int, size_t *);
-void gdb_cpu_setreg(int, register_t);
+void gdb_cpu_setreg(int, void *);
 int gdb_cpu_signal(int, int);
 
 #endif /* !_MACHINE_GDB_MACHDEP_H_ */
diff --git a/sys/amd64/amd64/gdb_machdep.c b/sys/amd64/amd64/gdb_machdep.c
index 770e9038e4e9..ea1c3eff10d1 100644
--- a/sys/amd64/amd64/gdb_machdep.c
+++ b/sys/amd64/amd64/gdb_machdep.c
@@ -81,14 +81,13 @@ gdb_cpu_getreg(int regnum, size_t *regsz)
 }
 
 void
-gdb_cpu_setreg(int regnum, register_t val)
+gdb_cpu_setreg(int regnum, void *val)
 {
 
-	val = __bswap64(val);
 	switch (regnum) {
 	case GDB_REG_PC:
-		kdb_thrctx->pcb_rip = val;
+		kdb_thrctx->pcb_rip = *(register_t *)val;
 		if (kdb_thread  == curthread)
-			kdb_frame->tf_rip = val;
+			kdb_frame->tf_rip = *(register_t *)val;
 	}
 }
diff --git a/sys/amd64/include/gdb_machdep.h b/sys/amd64/include/gdb_machdep.h
index 458f2f6eb9b5..c2fd8bf198d1 100644
--- a/sys/amd64/include/gdb_machdep.h
+++ b/sys/amd64/include/gdb_machdep.h
@@ -52,6 +52,6 @@ gdb_cpu_query(void)
 }
 
 void *gdb_cpu_getreg(int, size_t *);
-void gdb_cpu_setreg(int, register_t);
+void gdb_cpu_setreg(int, void *);
 
 #endif /* !_MACHINE_GDB_MACHDEP_H_ */
diff --git a/sys/gdb/gdb_main.c b/sys/gdb/gdb_main.c
index 0eed036aa9ce..bed693af3082 100644
--- a/sys/gdb/gdb_main.c
+++ b/sys/gdb/gdb_main.c
@@ -120,16 +120,22 @@ gdb_trap(int type, int code)
 			break;
 		case 'c': {	/* Continue. */
 			uintmax_t addr;
-			if (!gdb_rx_varhex(&addr))
-				gdb_cpu_setreg(GDB_REG_PC, addr);
+			register_t pc;
+			if (!gdb_rx_varhex(&addr)) {
+				pc = addr;
+				gdb_cpu_setreg(GDB_REG_PC, &pc);
+			}
 			kdb_cpu_clear_singlestep();
 			return (1);
 		}
 		case 'C': {	/* Continue with signal. */
 			uintmax_t addr, sig;
+			register_t pc;
 			if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
-			    !gdb_rx_varhex(&addr))
-				gdb_cpu_setreg(GDB_REG_PC, addr);
+			    !gdb_rx_varhex(&addr)) {
+				pc = addr;
+				gdb_cpu_setreg(GDB_REG_PC, &pc);
+			}
 			kdb_cpu_clear_singlestep();
 			return (1);
 		}
@@ -191,9 +197,11 @@ gdb_trap(int type, int code)
 			break;
 		}
 		case 'P': {	/* Write register. */
-			uintmax_t reg, val;
+			char *val;
+			uintmax_t reg;
+			val = gdb_rxp;
 			if (gdb_rx_varhex(&reg) || gdb_rx_char() != '=' ||
-			    gdb_rx_varhex(&val)) {
+			    !gdb_rx_mem(val, gdb_cpu_regsz(reg))) {
 				gdb_tx_err(EINVAL);
 				break;
 			}
@@ -226,16 +234,22 @@ gdb_trap(int type, int code)
 			break;
 		case 's': {	/* Step. */
 			uintmax_t addr;
-			if (!gdb_rx_varhex(&addr))
-				gdb_cpu_setreg(GDB_REG_PC, addr);
+			register_t pc;
+			if (!gdb_rx_varhex(&addr)) {
+				pc = addr;
+				gdb_cpu_setreg(GDB_REG_PC, &pc);
+			}
 			kdb_cpu_set_singlestep();
 			return (1);
 		}
 		case 'S': {	/* Step with signal. */
 			uintmax_t addr, sig;
+			register_t pc;
 			if (!gdb_rx_varhex(&sig) && gdb_rx_char() == ';' &&
-			    !gdb_rx_varhex(&addr))
-				gdb_cpu_setreg(GDB_REG_PC, addr);
+			    !gdb_rx_varhex(&addr)) {
+				pc = addr;
+				gdb_cpu_setreg(GDB_REG_PC, &pc);
+			}
 			kdb_cpu_set_singlestep();
 			return (1);
 		}
diff --git a/sys/i386/i386/gdb_machdep.c b/sys/i386/i386/gdb_machdep.c
index 836b13e73b89..042b1041c811 100644
--- a/sys/i386/i386/gdb_machdep.c
+++ b/sys/i386/i386/gdb_machdep.c
@@ -67,15 +67,14 @@ gdb_cpu_getreg(int regnum, size_t *regsz)
 }
 
 void
-gdb_cpu_setreg(int regnum, register_t val)
+gdb_cpu_setreg(int regnum, void *val)
 {
 
-	val = __bswap32(val);
 	switch (regnum) {
 	case GDB_REG_PC:
-		kdb_thrctx->pcb_eip = val;
+		kdb_thrctx->pcb_eip = *(register_t *)val;
 		if (kdb_thread  == curthread)
-			kdb_frame->tf_eip = val;
+			kdb_frame->tf_eip = *(register_t *)val;
 	}
 }
 
diff --git a/sys/i386/include/gdb_machdep.h b/sys/i386/include/gdb_machdep.h
index c67412a292ff..3b426a1e69cc 100644
--- a/sys/i386/include/gdb_machdep.h
+++ b/sys/i386/include/gdb_machdep.h
@@ -46,7 +46,7 @@ gdb_cpu_query(void)
 }
 
 void *gdb_cpu_getreg(int, size_t *);
-void gdb_cpu_setreg(int, register_t);
+void gdb_cpu_setreg(int, void *);
 int gdb_cpu_signal(int, int);
 
 #endif /* !_MACHINE_GDB_MACHDEP_H_ */
diff --git a/sys/ia64/ia64/gdb_machdep.c b/sys/ia64/ia64/gdb_machdep.c
index 62b475577832..7729d71fbae4 100644
--- a/sys/ia64/ia64/gdb_machdep.c
+++ b/sys/ia64/ia64/gdb_machdep.c
@@ -128,7 +128,7 @@ gdb_cpu_getreg(int regnum, size_t *regsz)
 }
 
 void
-gdb_cpu_setreg(int regnum, register_t val)
+gdb_cpu_setreg(int regnum, void *val)
 {
 
 	switch (regnum) {
diff --git a/sys/ia64/include/gdb_machdep.h b/sys/ia64/include/gdb_machdep.h
index 1b957fb8560d..b6294d7ab00e 100644
--- a/sys/ia64/include/gdb_machdep.h
+++ b/sys/ia64/include/gdb_machdep.h
@@ -41,7 +41,7 @@ gdb_cpu_regsz(int regnum)
 }
 
 void *gdb_cpu_getreg(int, size_t *);
-void gdb_cpu_setreg(int, register_t);
+void gdb_cpu_setreg(int, void *);
 int gdb_cpu_signal(int, int);
 int gdb_cpu_query(void);
 
diff --git a/sys/sparc64/include/gdb_machdep.h b/sys/sparc64/include/gdb_machdep.h
index b30ad04b634a..27fbe46c7e1a 100644
--- a/sys/sparc64/include/gdb_machdep.h
+++ b/sys/sparc64/include/gdb_machdep.h
@@ -52,6 +52,6 @@ gdb_cpu_signal(int vector, int _)
 }
 
 void *gdb_cpu_getreg(int, size_t *);
-void gdb_cpu_setreg(int, register_t);
+void gdb_cpu_setreg(int, void *);
 
 #endif /* !_MACHINE_GDB_MACHDEP_H_ */
diff --git a/sys/sparc64/sparc64/gdb_machdep.c b/sys/sparc64/sparc64/gdb_machdep.c
index 219ac13ffdb2..4a3d2e67fe02 100644
--- a/sys/sparc64/sparc64/gdb_machdep.c
+++ b/sys/sparc64/sparc64/gdb_machdep.c
@@ -63,7 +63,7 @@ gdb_cpu_getreg(int regnum, size_t *regsz)
 }
 
 void
-gdb_cpu_setreg(int regnum, register_t val)
+gdb_cpu_setreg(int regnum, void *val)
 {
 	switch (regnum) {
 	}