arch/mips: Add base MIPS architecture support

Add the build infrastructure and basic architectural support required
to build for targets using the MIPS architecture. This is sufficient
to run on a simulator, but will require the addition of some cache
maintenance and timer setup in order to run on real hardware.

BUG=chrome-os-partner:31438, chromium:409082
TEST=none yet

Change-Id: I027902d8408e419b626d0aab7768bc564bd49047
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: fcc0d934d7223922c878b1f87021cb5c2d7e6f21
Original-Change-Id: If4f99554463bd3760fc142477440326fd16c67cc
Original-Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/207972
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8760
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/arch/mips/early_console.c

@@ -0,0 +1,55 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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 <console/console.h>
+#include <console/vtxprintf.h>
+
+void console_tx_byte(unsigned char byte)
+{
+	if (byte == '\n')
+		console_tx_byte('\r');
+
+#if CONFIG_CONSOLE_SERIAL_UART
+	uart_tx_byte(byte);
+#endif
+}
+
+void console_tx_flush(void)
+{
+#if CONFIG_CONSOLE_SERIAL_UART
+	uart_tx_flush();
+#endif
+}
+
+int do_printk(int msg_level, const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	if (msg_level > console_loglevel)
+		return 0;
+
+	va_start(args, fmt);
+	i = vtxprintf(console_tx_byte, fmt, args);
+	va_end(args);
+
+	console_tx_flush();
+
+	return i;
+}