Improving third-party hardware support:

- moving back to multple cores per platform
- using target instead of platform
- moving per-board and per-programmer preferences out of Preferences.java and into a new Target class
- adding a new "target" preference
- support for platform:value values in board preferences for bootloader path and core
- XXX: need to support platform:value syntax for board upload.using preferences.

1 files changed, 250 insertions, 0 deletions

diff --git a/cores/arduino/wiring.c b/cores/arduino/wiring.c
new file mode 100755
index 0000000..72bc282
--- /dev/null
+++ b/cores/arduino/wiring.c
@@ -0,0 +1,250 @@
+/*
+  wiring.c - Partial implementation of the Wiring API for the ATmega8.
+  Part of Arduino - http://www.arduino.cc/
+
+  Copyright (c) 2005-2006 David A. Mellis
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General
+  Public License along with this library; if not, write to the
+  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+  Boston, MA  02111-1307  USA
+
+  $Id$
+*/
+
+#include "wiring_private.h"
+
+// the prescaler is set so that timer0 ticks every 64 clock cycles, and the
+// the overflow handler is called every 256 ticks.
+#define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(64 * 256))
+
+// the whole number of milliseconds per timer0 overflow
+#define MILLIS_INC (MICROSECONDS_PER_TIMER0_OVERFLOW / 1000)
+
+// the fractional number of milliseconds per timer0 overflow. we shift right
+// by three to fit these numbers into a byte. (for the clock speeds we care
+// about - 8 and 16 MHz - this doesn't lose precision.)
+#define FRACT_INC ((MICROSECONDS_PER_TIMER0_OVERFLOW % 1000) >> 3)
+#define FRACT_MAX (1000 >> 3)
+
+volatile unsigned long timer0_overflow_count = 0;
+volatile unsigned long timer0_millis = 0;
+static unsigned char timer0_fract = 0;
+
+SIGNAL(TIMER0_OVF_vect)
+{
+	// copy these to local variables so they can be stored in registers
+	// (volatile variables must be read from memory on every access)
+	unsigned long m = timer0_millis;
+	unsigned char f = timer0_fract;
+
+	m += MILLIS_INC;
+	f += FRACT_INC;
+	if (f >= FRACT_MAX) {
+		f -= FRACT_MAX;
+		m += 1;
+	}
+
+	timer0_fract = f;
+	timer0_millis = m;
+	timer0_overflow_count++;
+}
+
+unsigned long millis()
+{
+	unsigned long m;
+	uint8_t oldSREG = SREG;
+
+	// disable interrupts while we read timer0_millis or we might get an
+	// inconsistent value (e.g. in the middle of a write to timer0_millis)
+	cli();
+	m = timer0_millis;
+	SREG = oldSREG;
+
+	return m;
+}
+
+unsigned long micros() {
+	unsigned long m, t;
+	uint8_t oldSREG = SREG;
+	
+	cli();	
+	t = TCNT0;
+  
+#ifdef TIFR0
+	if ((TIFR0 & _BV(TOV0)) && (t == 0))
+		t = 256;
+#else
+	if ((TIFR & _BV(TOV0)) && (t == 0))
+		t = 256;
+#endif
+
+	m = timer0_overflow_count;
+	SREG = oldSREG;
+	
+	return ((m << 8) + t) * (64 / clockCyclesPerMicrosecond());
+}
+
+void delay(unsigned long ms)
+{
+	unsigned long start = millis();
+	
+	while (millis() - start <= ms)
+		;
+}
+
+/* Delay for the given number of microseconds.  Assumes a 8 or 16 MHz clock. 
+ * Disables interrupts, which will disrupt the millis() function if used
+ * too frequently. */
+void delayMicroseconds(unsigned int us)
+{
+	uint8_t oldSREG;
+
+	// calling avrlib's delay_us() function with low values (e.g. 1 or
+	// 2 microseconds) gives delays longer than desired.
+	//delay_us(us);
+
+#if F_CPU >= 16000000L
+	// for the 16 MHz clock on most Arduino boards
+
+	// for a one-microsecond delay, simply return.  the overhead
+	// of the function call yields a delay of approximately 1 1/8 us.
+	if (--us == 0)
+		return;
+
+	// the following loop takes a quarter of a microsecond (4 cycles)
+	// per iteration, so execute it four times for each microsecond of
+	// delay requested.
+	us <<= 2;
+
+	// account for the time taken in the preceeding commands.
+	us -= 2;
+#else
+	// for the 8 MHz internal clock on the ATmega168
+
+	// for a one- or two-microsecond delay, simply return.  the overhead of
+	// the function calls takes more than two microseconds.  can't just
+	// subtract two, since us is unsigned; we'd overflow.
+	if (--us == 0)
+		return;
+	if (--us == 0)
+		return;
+
+	// the following loop takes half of a microsecond (4 cycles)
+	// per iteration, so execute it twice for each microsecond of
+	// delay requested.
+	us <<= 1;
+    
+	// partially compensate for the time taken by the preceeding commands.
+	// we can't subtract any more than this or we'd overflow w/ small delays.
+	us--;
+#endif
+
+	// disable interrupts, otherwise the timer 0 overflow interrupt that
+	// tracks milliseconds will make us delay longer than we want.
+	oldSREG = SREG;
+	cli();
+
+	// busy wait
+	__asm__ __volatile__ (
+		"1: sbiw %0,1" "\n\t" // 2 cycles
+		"brne 1b" : "=w" (us) : "0" (us) // 2 cycles
+	);
+
+	// reenable interrupts.
+	SREG = oldSREG;
+}
+
+void init()
+{
+	// this needs to be called before setup() or some functions won't
+	// work there
+	sei();
+	
+	// on the ATmega168, timer 0 is also used for fast hardware pwm
+	// (using phase-correct PWM would mean that timer 0 overflowed half as often
+	// resulting in different millis() behavior on the ATmega8 and ATmega168)
+#if !defined(__AVR_ATmega8__)
+	sbi(TCCR0A, WGM01);
+	sbi(TCCR0A, WGM00);
+#endif  
+	// set timer 0 prescale factor to 64
+#if defined(__AVR_ATmega8__)
+	sbi(TCCR0, CS01);
+	sbi(TCCR0, CS00);
+#else
+	sbi(TCCR0B, CS01);
+	sbi(TCCR0B, CS00);
+#endif
+	// enable timer 0 overflow interrupt
+#if defined(__AVR_ATmega8__)
+	sbi(TIMSK, TOIE0);
+#else
+	sbi(TIMSK0, TOIE0);
+#endif
+
+	// timers 1 and 2 are used for phase-correct hardware pwm
+	// this is better for motors as it ensures an even waveform
+	// note, however, that fast pwm mode can achieve a frequency of up
+	// 8 MHz (with a 16 MHz clock) at 50% duty cycle
+
+	// set timer 1 prescale factor to 64
+	sbi(TCCR1B, CS11);
+	sbi(TCCR1B, CS10);
+	// put timer 1 in 8-bit phase correct pwm mode
+	sbi(TCCR1A, WGM10);
+
+	// set timer 2 prescale factor to 64
+#if defined(__AVR_ATmega8__)
+	sbi(TCCR2, CS22);
+#else
+	sbi(TCCR2B, CS22);
+#endif
+	// configure timer 2 for phase correct pwm (8-bit)
+#if defined(__AVR_ATmega8__)
+	sbi(TCCR2, WGM20);
+#else
+	sbi(TCCR2A, WGM20);
+#endif
+
+#if defined(__AVR_ATmega1280__)
+	// set timer 3, 4, 5 prescale factor to 64
+	sbi(TCCR3B, CS31);	sbi(TCCR3B, CS30);
+	sbi(TCCR4B, CS41);	sbi(TCCR4B, CS40);
+	sbi(TCCR5B, CS51);	sbi(TCCR5B, CS50);
+	// put timer 3, 4, 5 in 8-bit phase correct pwm mode
+	sbi(TCCR3A, WGM30);
+	sbi(TCCR4A, WGM40);
+	sbi(TCCR5A, WGM50);
+#endif
+
+	// set a2d prescale factor to 128
+	// 16 MHz / 128 = 125 KHz, inside the desired 50-200 KHz range.
+	// XXX: this will not work properly for other clock speeds, and
+	// this code should use F_CPU to determine the prescale factor.
+	sbi(ADCSRA, ADPS2);
+	sbi(ADCSRA, ADPS1);
+	sbi(ADCSRA, ADPS0);
+
+	// enable a2d conversions
+	sbi(ADCSRA, ADEN);
+
+	// the bootloader connects pins 0 and 1 to the USART; disconnect them
+	// here so they can be used as normal digital i/o; they will be
+	// reconnected in Serial.begin()
+#if defined(__AVR_ATmega8__)
+	UCSRB = 0;
+#else
+	UCSR0B = 0;
+#endif
+}
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