diff --git a/gdbstub.c b/gdbstub.c
index e561244..3965980 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -272,7 +272,20 @@ static int gdb_signal_to_target (int sig)
         return -1;
 }
 
-//#define DEBUG_GDB
+/* #define DEBUG_GDB */
+
+#ifdef DEBUG_GDB
+# define DEBUG_GDB_GATE 1
+#else
+# define DEBUG_GDB_GATE 0
+#endif
+
+#define gdb_debug(fmt, ...) do { \
+    if (DEBUG_GDB_GATE) { \
+        fprintf(stderr, "%s: " fmt, __func__, ## __VA_ARGS__); \
+    } \
+} while (0)
+
 
 typedef struct GDBRegisterState {
     int base_reg;
@@ -548,9 +561,7 @@ static int put_packet_binary(GDBState *s, const char *buf, int len)
 /* return -1 if error, 0 if OK */
 static int put_packet(GDBState *s, const char *buf)
 {
-#ifdef DEBUG_GDB
-    printf("reply='%s'\n", buf);
-#endif
+    gdb_debug("reply='%s'\n", buf);
 
     return put_packet_binary(s, buf, strlen(buf));
 }
@@ -956,9 +967,9 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
     uint8_t *registers;
     target_ulong addr, len;
 
-#ifdef DEBUG_GDB
-    printf("command='%s'\n", line_buf);
-#endif
+
+    gdb_debug("command='%s'\n", line_buf);
+
     p = line_buf;
     ch = *p++;
     switch(ch) {
@@ -1519,17 +1530,14 @@ static void gdb_read_byte(GDBState *s, int ch)
         /* Waiting for a response to the last packet.  If we see the start
            of a new command then abandon the previous response.  */
         if (ch == '-') {
-#ifdef DEBUG_GDB
-            printf("Got NACK, retransmitting\n");
-#endif
+            gdb_debug("Got NACK, retransmitting\n");
             put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
+        } else if (ch == '+') {
+            gdb_debug("Got ACK\n");
+        } else {
+            gdb_debug("Got '%c' when expecting ACK/NACK\n", ch);
         }
-#ifdef DEBUG_GDB
-        else if (ch == '+')
-            printf("Got ACK\n");
-        else
-            printf("Got '%c' when expecting ACK/NACK\n", ch);
-#endif
+
         if (ch == '+' || ch == '$')
             s->last_packet_len = 0;
         if (ch != '$')
@@ -1550,9 +1558,7 @@ static void gdb_read_byte(GDBState *s, int ch)
                 s->line_sum = 0;
                 s->state = RS_GETLINE;
             } else {
-#ifdef DEBUG_GDB
-                printf("gdbstub received garbage between packets: 0x%x\n", ch);
-#endif
+                gdb_debug("received garbage between packets: 0x%x\n", ch);
             }
             break;
         case RS_GETLINE:
@@ -1568,9 +1574,7 @@ static void gdb_read_byte(GDBState *s, int ch)
                 /* end of command, start of checksum*/
                 s->state = RS_CHKSUM1;
             } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
-#ifdef DEBUG_GDB
-                printf("gdbstub command buffer overrun, dropping command\n");
-#endif
+                gdb_debug("command buffer overrun, dropping command\n");
                 s->state = RS_IDLE;
             } else {
                 /* unescaped command character */
@@ -1584,9 +1588,7 @@ static void gdb_read_byte(GDBState *s, int ch)
                 s->state = RS_CHKSUM1;
             } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
                 /* command buffer overrun */
-#ifdef DEBUG_GDB
-                printf("gdbstub command buffer overrun, dropping command\n");
-#endif
+                gdb_debug("command buffer overrun, dropping command\n");
                 s->state = RS_IDLE;
             } else {
                 /* parse escaped character and leave escape state */
@@ -1598,25 +1600,18 @@ static void gdb_read_byte(GDBState *s, int ch)
         case RS_GETLINE_RLE:
             if (ch < ' ') {
                 /* invalid RLE count encoding */
-#ifdef DEBUG_GDB
-                printf("gdbstub got invalid RLE count: 0x%x\n", ch);
-#endif
+                gdb_debug("got invalid RLE count: 0x%x\n", ch);
                 s->state = RS_GETLINE;
             } else {
                 /* decode repeat length */
                 int repeat = (unsigned char)ch - ' ' + 3;
                 if (s->line_buf_index + repeat >= sizeof(s->line_buf) - 1) {
                     /* that many repeats would overrun the command buffer */
-#ifdef DEBUG_GDB
-                    printf("gdbstub command buffer overrun,"
-                           " dropping command\n");
-#endif
+                    gdb_debug("command buffer overrun, dropping command\n");
                     s->state = RS_IDLE;
                 } else if (s->line_buf_index < 1) {
                     /* got a repeat but we have nothing to repeat */
-#ifdef DEBUG_GDB
-                    printf("gdbstub got invalid RLE sequence\n");
-#endif
+                    gdb_debug("got invalid RLE sequence\n");
                     s->state = RS_GETLINE;
                 } else {
                     /* repeat the last character */
@@ -1631,9 +1626,7 @@ static void gdb_read_byte(GDBState *s, int ch)
         case RS_CHKSUM1:
             /* get high hex digit of checksum */
             if (!isxdigit(ch)) {
-#ifdef DEBUG_GDB
-                printf("gdbstub got invalid command checksum digit\n");
-#endif
+                gdb_debug("got invalid command checksum digit\n");
                 s->state = RS_GETLINE;
                 break;
             }
@@ -1644,21 +1637,17 @@ static void gdb_read_byte(GDBState *s, int ch)
         case RS_CHKSUM2:
             /* get low hex digit of checksum */
             if (!isxdigit(ch)) {
-#ifdef DEBUG_GDB
-                printf("gdbstub got invalid command checksum digit\n");
-#endif
+                gdb_debug("got invalid command checksum digit\n");
                 s->state = RS_GETLINE;
                 break;
             }
             s->line_csum |= fromhex(ch);
 
             if (s->line_csum != (s->line_sum & 0xff)) {
+                gdb_debug("got command packet with incorrect checksum\n");
                 /* send NAK reply */
                 reply = '-';
                 put_buffer(s, &reply, 1);
-#ifdef DEBUG_GDB
-                printf("gdbstub got command packet with incorrect checksum\n");
-#endif
                 s->state = RS_IDLE;
             } else {
                 /* send ACK reply */
