uio_usbdebug: User-space-i/o framework for usbdebug

uio_usbdebug enables you to debug coreboot's usbdebug driver inside a
running operating system (only Linux at this time). This comes very
handy if you're hacking the usbdebug driver and don't have any other
debug output from coreboot itself.

Currently, only Intel chipsets are supported.

Change-Id: Iaf0bcd4b4c01ae0b099d1206d553344054a62f31
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: http://review.coreboot.org/4695
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/util/uio_usbdebug/console/printk.c b/util/uio_usbdebug/console/printk.c
new file mode 100644
index 0000000..a73407c
--- /dev/null
+++ b/util/uio_usbdebug/console/printk.c
@@ -0,0 +1,34 @@
+/*
+ * This file is part of uio_usbdebug
+ *
+ * Copyright (C) 2013 Nico Huber <nico.h@gmx.de>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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 <stdio.h>
+#include <stdarg.h>
+#include <console/console.h>
+
+int do_printk(int msg_level, const char *const fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	i = vfprintf(stderr, fmt, args);
+	va_end(args);
+
+	return i;
+}