[GDB] Remote debugging over UDP

This commit implements GDB over UDP.  Using UDP is more complex than
serial and has required some restructuring.

The GDB stub is now built using one or both of GDBSERIAL and GDBUDP
config.h options.

To enter the debugger, execute the gPXE shell command:
gdbstub <transport> [<options>...]

Where <transport> is "serial" or "udp".  For "udp", the name of a
configured network device is required:
gdbstub udp net0

The GDB stub listens on UDP port 43770 by default.

1 files changed, 105 insertions, 0 deletions

diff --git a/src/hci/commands/gdbstub_cmd.c b/src/hci/commands/gdbstub_cmd.c
new file mode 100644
index 00000000..74167525
--- /dev/null
+++ b/src/hci/commands/gdbstub_cmd.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2008 Stefan Hajnoczi <stefanha@gmail.com>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <gpxe/command.h>
+#include <gpxe/gdbstub.h>
+
+/** @file
+ *
+ * GDB stub command
+ *
+ */
+
+/**
+ * "gdbstub" command syntax message
+ *
+ * @v argv		Argument list
+ */
+static void gdbstub_syntax ( char **argv ) {
+	printf ( "Usage:\n"
+		 "  %s <transport> [<options>...]\n"
+		 "\n"
+		 "Start remote debugging using one of the following transports:\n"
+		 "  serial           use serial port (if compiled in)\n"
+		 "  udp <interface>  use UDP over network interface (if compiled in)\n",
+		 argv[0] );
+}
+
+/**
+ * The "gdbstub" command
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @ret rc		Exit code
+ */
+static int gdbstub_exec ( int argc, char **argv ) {
+	static struct option longopts[] = {
+		{ "help", 0, NULL, 'h' },
+		{ NULL, 0, NULL, 0 },
+	};
+	const char *trans_name;
+	struct gdb_transport *trans;
+	int c;
+
+	/* Parse options */
+	while ( ( c = getopt_long ( argc, argv, "h", longopts, NULL ) ) >= 0 ){
+		switch ( c ) {
+		case 'h':
+			/* Display help text */
+		default:
+			/* Unrecognised/invalid option */
+			gdbstub_syntax ( argv );
+			return 1;
+		}
+	}
+
+	/* At least one argument */
+	if ( optind == argc ) {
+		gdbstub_syntax ( argv );
+		return 1;
+	}
+
+	trans_name = argv[optind++];
+
+	/* Initialise transport */
+	trans = find_gdb_transport ( trans_name );
+	if ( !trans ) {
+		printf ( "%s: no such transport (is it compiled in?)\n", trans_name );
+		return 1;
+	}
+
+	if ( trans->init ) {
+		if ( trans->init ( argc - optind, &argv[optind] ) != 0 ) {
+			return 1;
+		}
+	}
+
+	/* Enter GDB stub */
+	gdbstub_start ( trans );
+	return 0;
+}
+
+/** GDB stub commands */
+struct command gdbstub_commands[] __command = {
+	{
+		.name = "gdbstub",
+		.exec = gdbstub_exec,
+	},
+};