From 30a3e1570d74be9efa0a1a09d6fc9ec979627f99 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Fri, 13 May 2011 01:27:22 -0700
Subject: altos-avr: Initial OS port to AVR

This is working with output to the serial line

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 src-avr/ao_debug_avr.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src-avr/ao_debug_avr.c

(limited to 'src-avr/ao_debug_avr.c')

diff --git a/src-avr/ao_debug_avr.c b/src-avr/ao_debug_avr.c
new file mode 100644
index 00000000..2e41e15a
--- /dev/null
+++ b/src-avr/ao_debug_avr.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+void
+uart_send(char c)
+{
+	loop_until_bit_is_set(UCSR1A, UDRE1);
+	UDR1 = c;
+}
+
+int
+uart_put(char c, FILE *stream)
+{
+	if (c == '\n')
+		uart_send('\r');
+	uart_send(c);
+	return 0;
+}
+
+int
+uart_get(FILE *stream)
+{
+	loop_until_bit_is_set(UCSR1A, RXC1);
+	return (int) UDR1 & 0xff;
+}
+
+void
+uart_init(uint16_t baud)
+{
+	PRR1 &= ~(1 << PRUSART1);
+	UBRR1L = baud;
+	UBRR1H = baud >> 8;
+	UCSR1A = 0;
+	UCSR1B = ((1 << RXEN1) |	/* Enable receiver */
+		  (1 << TXEN1));	/* Enable transmitter */
+	UCSR1C = ((0 << UMSEL10) |	/* Asynchronous mode */
+		  (0 << UPM10) |	/* No parity */
+		  (0 << USBS1) |	/* 1 stop bit */
+		  (3 << UCSZ10) |	/* 8 bit characters */
+		  (0 << UCPOL1));	/* MBZ for async mode */
+}
+
+static FILE mystdout = FDEV_SETUP_STREAM(uart_put, NULL, _FDEV_SETUP_WRITE);
+
+static FILE mystdin = FDEV_SETUP_STREAM(NULL, uart_get, _FDEV_SETUP_READ);
+
+void	ao_debug_init(void)
+{
+	uart_init(F_CPU / (16UL * 9600UL) - 1);
+
+	stdout = &mystdout;
+	stdin = &mystdin;
+
+	if (DDRB & AO_LED_RED) {
+		printf ("oops, starting all over\n");
+		for (;;)
+			;
+	}
+	DDRB |= (1 << 7);
+	PORTB |= (1 << 7);
+	printf ("debug initialized\n");
+}
-- 
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