2003-07-17 Joel Sherrill <joel@OARcorp.com>

	PR 433/tools
	* mips-stub.c: Patch from C. M. Heard <heard@pobox.com> described as:

	The purpose of the patch is to make the stub ignore all
	characters except '+' (ack) or '-' (nak) when it has transmitted a
	packet and expects an acknowledgment. Without the patch,
	putpacket() will retransmit each time it receives anything other
	than '+' when expecting an ack, and that, bitter experience has
	found, frequently results in the stub failing to sync up when
	initially attaching to gdb.

	I think that rtems users will notice significant improvement in
	the of the mips stub if this patch is incorporated in the
	distribution; certainly I did in my stand-aline environment. I
	should hasten to add that it is only an improvement and not a 100%
	cure for synchronization problems because '+' characters can (and
	do) during as message data, and it's still possible for these to
	be mistaken as acks. I have no idea how to fix that short of
	redesigning the gdb-remote protocol.

2 files changed, 41 insertions, 1 deletions

diff --git a/c/src/lib/libbsp/mips/shared/gdbstub/ChangeLog b/c/src/lib/libbsp/mips/shared/gdbstub/ChangeLog
index b870b2a58a..8a034fb7d4 100644
--- a/c/src/lib/libbsp/mips/shared/gdbstub/ChangeLog
+++ b/c/src/lib/libbsp/mips/shared/gdbstub/ChangeLog
@@ -1,3 +1,25 @@
+2003-07-17	Joel Sherrill <joel@OARcorp.com>
+
+	PR 433/tools
+	* mips-stub.c: Patch from C. M. Heard <heard@pobox.com> described as:
+
+	The purpose of the patch is to make the stub ignore all
+	characters except '+' (ack) or '-' (nak) when it has transmitted a
+	packet and expects an acknowledgment. Without the patch,
+	putpacket() will retransmit each time it receives anything other
+	than '+' when expecting an ack, and that, bitter experience has
+	found, frequently results in the stub failing to sync up when
+	initially attaching to gdb.
+
+	I think that rtems users will notice significant improvement in
+	the of the mips stub if this patch is incorporated in the
+	distribution; certainly I did in my stand-aline environment. I
+	should hasten to add that it is only an improvement and not a 100%
+	cure for synchronization problems because '+' characters can (and
+	do) during as message data, and it's still possible for these to
+	be mistaken as acks. I have no idea how to fix that short of
+	redesigning the gdb-remote protocol.
+
 2002-11-01	Joel Sherrill <joel@OARcorp.com>
 
 	* mips-stub.c: Removed warnings.
diff --git a/c/src/lib/libbsp/mips/shared/gdbstub/mips-stub.c b/c/src/lib/libbsp/mips/shared/gdbstub/mips-stub.c
index d0ef76228b..a3ce56ade3 100644
--- a/c/src/lib/libbsp/mips/shared/gdbstub/mips-stub.c
+++ b/c/src/lib/libbsp/mips/shared/gdbstub/mips-stub.c
@@ -599,6 +599,24 @@ getpacket (char *buffer)
 
 
 /*
+ * Get a positive/negative acknowledgment for a transmitted packet.
+ */
+static char
+getAck (void)
+{
+  char c;
+
+  do
+    {
+      c = getDebugChar ();
+    }
+  while ((c != '+') && (c != '-'));
+
+  return c;
+}
+
+
+/*
  * Send the packet in buffer and wait for a positive acknowledgement.
  */
 static void
@@ -644,7 +662,7 @@ putpacket (char *buffer)
       putDebugChar (highhex (checksum));
       putDebugChar (lowhex (checksum));
     }
-  while  (getDebugChar () != '+');
+  while  (getAck () != '+');
 }