Split the (quick hack) boot logic out from main.c to autoboot.c, add a

"boot" command to attempt booting from within the command shell, fall back
to shell if boot fails for any reason.

src/usr/autoboot.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 <vsprintf.h>
+#include <gpxe/autoboot.h>
+
+/** @file
+ *
+ * Automatic booting
+ *
+ */
+
+#include <gpxe/netdevice.h>
+void test_dhcp ( struct net_device *netdev );
+
+void autoboot ( void ) {
+	struct net_device *netdev;
+
+	netdev = next_netdev ();
+	if ( netdev ) {
+		test_dhcp ( netdev );
+	} else {
+		printf ( "No network device found\n" );
+	}
+}