1 files changed, 124 insertions, 0 deletions
diff --git a/payloads/libpayload/gdb/stub.c b/payloads/libpayload/gdb/stub.c
new file mode 100644
index 0000000000..73afa70c47
--- /dev/null
+++ b/payloads/libpayload/gdb/stub.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * 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 (at your option) 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <gdb.h>
+#include <libpayload.h>
+
+struct gdb_state gdb_state;
+
+static u8 reply_buf[2048];
+static u8 command_buf[2048];
+
+static struct gdb_message command = {
+	.buf = command_buf,
+	.used = 0,
+	.size = sizeof(command_buf),
+};
+static struct gdb_message reply = {
+	.buf = reply_buf,
+	.used = 0,
+	.size = sizeof(reply_buf),
+};
+
+void gdb_command_loop(u8 signal)
+{
+	if (gdb_state.resumed) {
+		/* We were just running. Send a stop reply. */
+		reply.used = 0;
+		gdb_message_add_string(&reply, "S");
+		gdb_message_encode_bytes(&reply, &signal, 1);
+		gdb_send_reply(&reply);
+
+	}
+	gdb_state.signal = signal;
+	gdb_state.resumed = 0;
+	gdb_state.connected = 1;
+
+	while (1) {
+		int i;
+
+		gdb_get_command(&command);
+
+		reply.used = 0;
+		for (i = 0; i < gdb_command_count; i++) {
+			int clen = strlen(gdb_commands[i].str);
+			if (!strncmp(gdb_commands[i].str, (char *)command.buf,
+				     MIN(clen, command.used))) {
+				gdb_commands[i].handler(&command, clen, &reply);
+				break;
+			}
+		}
+
+		/* If we're resuming, we won't send a reply until we stop. */
+		if (gdb_state.resumed)
+			return;
+
+		gdb_send_reply(&reply);
+	}
+}
+
+static void gdb_output_write(const void *buffer, size_t count)
+{
+	if (!gdb_state.resumed) {
+		/* Must be a die_if() in GDB (or a bug), so bail out and die. */
+		gdb_exit(-1);
+		video_console_init();
+		puts("GDB died, redirecting its last words to the screen:\n");
+		console_write(buffer, count);
+	} else {
+		reply.used = 0;
+		reply.buf[reply.used++] = 'O';
+		gdb_message_encode_bytes(&reply, buffer, count);
+		gdb_send_reply(&reply);
+	}
+}
+
+static struct console_output_driver gdb_output_driver = {
+	.write = &gdb_output_write
+};
+
+static void gdb_init(void)
+{
+	printf("Ready for GDB connection.\n");
+	gdb_transport_init();
+	gdb_arch_init();
+	console_add_output_driver(&gdb_output_driver);
+}
+
+void gdb_enter(void)
+{
+	if (!gdb_state.connected)
+		gdb_init();
+	gdb_arch_enter();
+}
+
+void gdb_exit(s8 exit_status)
+{
+	if (!gdb_state.connected)
+		return;
+
+	reply.used = 0;
+	gdb_message_add_string(&reply, "W");
+	gdb_message_encode_bytes(&reply, &exit_status, 1);
+	gdb_send_reply(&reply);
+
+	console_remove_output_driver(&gdb_output_write);
+	gdb_transport_teardown();
+	gdb_state.connected = 0;
+	printf("Detached from GDB connection.\n");
+}