Index: head/sys/mips/atheros/uart_bus_ar933x.c
===================================================================
--- head/sys/mips/atheros/uart_bus_ar933x.c	(revision 310780)
+++ head/sys/mips/atheros/uart_bus_ar933x.c	(revision 310781)
@@ -1,91 +1,115 @@
 /*-
  * Copyright (c) 2012, Adrian Chadd <adrian@FreeBSD.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  */
 #include "opt_uart.h"
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bus.h>
 #include <sys/conf.h>
 #include <sys/kernel.h>
 #include <sys/module.h>
 
 #include <machine/bus.h>
 
 #include <dev/uart/uart.h>
 #include <dev/uart/uart_cpu.h>
 #include <dev/uart/uart_bus.h>
 
 #include <mips/atheros/ar71xxreg.h>
 #include <mips/atheros/ar71xx_cpudef.h>
 
 #include <mips/atheros/uart_dev_ar933x.h>
+#ifdef	EARLY_PRINTF
+#include <mips/atheros/ar933x_uart.h>
+#endif
 
 #include "uart_if.h"
 
 static int uart_ar933x_probe(device_t dev);
 extern struct uart_class uart_ar933x_uart_class;
 
 static device_method_t uart_ar933x_methods[] = {
 	/* Device interface */
 	DEVMETHOD(device_probe,		uart_ar933x_probe),
 	DEVMETHOD(device_attach,	uart_bus_attach),
 	DEVMETHOD(device_detach,	uart_bus_detach),
 	{ 0, 0 }
 };
 
 static driver_t uart_ar933x_driver = {
 	uart_driver_name,
 	uart_ar933x_methods,
 	sizeof(struct uart_softc),
 };
 
 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
 
 static int
 uart_ar933x_probe(device_t dev)
 {
 	struct uart_softc *sc;
 	uint64_t freq;
 
 	freq = ar71xx_uart_freq();
 
 	sc = device_get_softc(dev);
 	sc->sc_sysdev = SLIST_FIRST(&uart_sysdevs);
 	sc->sc_class = &uart_ar933x_class;
 	bcopy(&sc->sc_sysdev->bas, &sc->sc_bas, sizeof(sc->sc_bas));
 	sc->sc_sysdev->bas.regshft = 0;
 	sc->sc_sysdev->bas.bst = mips_bus_space_generic;
 	sc->sc_sysdev->bas.bsh = MIPS_PHYS_TO_KSEG1(AR71XX_UART_ADDR);
 	sc->sc_bas.regshft = 0;
 	sc->sc_bas.bst = mips_bus_space_generic;
 	sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(AR71XX_UART_ADDR);
 
 	return (uart_bus_probe(dev, 2, freq, 0, 0));
 }
+
+/*
+ * Assume the UART is setup by the bootloader and just echo that.
+ */
+#if	defined(EARLY_PRINTF)
+static void
+ar933x_early_putc(int c)
+{
+	int i = 1000;
+
+	/* Wait until FIFO is clear */
+	while ((i > 0) && (ATH_READ_REG(AR71XX_UART_ADDR + AR933X_UART_CS_REG) &
+	     AR933X_UART_CS_TX_BUSY))
+		i--;
+
+	/* Write it out */
+	ATH_WRITE_REG(AR71XX_UART_ADDR + AR933X_UART_DATA_REG,
+	    (c  & 0xff)| AR933X_UART_DATA_TX_CSR);
+}
+early_putc_t *early_putc = ar933x_early_putc;
+#endif	/* EARLY_PRINTF */
 
 DRIVER_MODULE(uart, apb, uart_ar933x_driver, uart_devclass, 0, 0);