* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
-#include <avr/io.h>
-#include <avr/interrupt.h>
-#define TEENSY 0
-#if TEENSY
-#define F_CPU 16000000UL // 16 MHz
-#else
-#define F_CPU 8000000UL // 8 MHz
-#endif
-#include <util/delay.h>
-
-#define LEDOUT PORTB7
-#define LEDPORT PORTB
-#define LEDDDR DDRB
-#define LEDDDRPIN DD7
-
-static void
-adc_start(void);
-
-ISR(TIMER1_COMPA_vect)
-{
- adc_start();
-}
-
-static void
-timer1_init(void)
-{
- TCCR1A = ((0 << WGM11) | /* CTC mode, OCR1A */
- (0 << WGM10)); /* CTC mode, OCR1A */
- TCCR1B = ((0 << ICNC1) | /* no input capture noise canceler */
- (0 << ICES1) | /* input capture on falling edge (don't care) */
- (0 << WGM13) | /* CTC mode, OCR1A */
- (1 << WGM12) | /* CTC mode, OCR1A */
- (3 << CS10)); /* clk/64 from prescaler */
-
-#if TEENSY
- OCR1A = 2500; /* 16MHz clock */
-#else
- OCR1A = 1250; /* 8MHz clock */
-#endif
-
- TIMSK1 = (1 << OCIE1A); /* Interrupt on compare match */
-}
-
-static void
-clock_init(void)
-{
- /* disable RC clock */
- CLKSEL0 &= ~(1 << RCE);
-
- /* Disable PLL */
- PLLCSR &= ~(1 << PLLE);
-
- /* Enable external clock */
- CLKSEL0 |= (1 << EXTE);
-
- /* wait for external clock to be ready */
- while ((CLKSTA & (1 << EXTON)) == 0)
- ;
-
- /* select external clock */
- CLKSEL0 |= (1 << CLKS);
-
- /* Disable the clock prescaler */
- cli();
- CLKPR = (1 << CLKPCE);
- CLKPR = 0;
- sei();
-
- /* Set up the PLL to use the crystal */
-
- /* Use primary system clock as PLL source */
- PLLFRQ = ((0 << PINMUX) | /* Use primary clock */
- (0 << PLLUSB) | /* No divide by 2 for USB */
- (0 << PLLTM0) | /* Disable high speed timer */
- (0x4 << PDIV0)); /* 48MHz PLL clock */
-
- /* Set the frequency of the crystal */
-#if TEENSY
- PLLCSR |= (1 << PINDIV); /* For 16MHz crystal on Teensy board */
-#else
- PLLCSR &= ~(1 << PINDIV); /* For 8MHz crystal on TeleScience board */
-#endif
-
- /* Enable the PLL */
- PLLCSR |= (1 << PLLE);
- while (!(PLLCSR & (1 << PLOCK)))
- ;
-}
-
-static void
-timer0_init(void)
-{
- TCCR0A = ((1 << COM0A1) |
- (0 << COM0A0) |
- (1 << WGM01) |
- (1 << WGM00));
-
- OCR0A = 0x10;
- OCR0B = 0;
- TIMSK0 = 0;
-
- TCCR0B = ((0 << WGM02) |
- (5 << CS00));
-}
-
-ISR(ADC_vect)
-{
- OCR0A = ADCH;
-}
-
-#define ADC_CHANNEL 0x25 /* Channel ADC13 */
-#define ADC_CHANNEL_LOW(c) (((c) & 0x1f) << MUX0)
-#define ADC_CHANNEL_HIGH(c) ((((c) & 0x20) >> 5) << MUX5)
-
-#define ADCSRA_INIT ((1 << ADEN) | /* Enable ADC */ \
- (0 << ADATE) | /* No auto ADC trigger */ \
- (1 << ADIE) | /* Enable interrupt */ \
- (6 << ADPS0)) /* Prescale clock by 64 */
-
-#define ADCSRB_INIT ((0 << ADHSM) | /* No high-speed mode */ \
- (0 << ACME) | /* Some comparitor thing */ \
- (0 << ADTS0)) /* Free running mode (don't care) */
-
-static void
-adc_start(void)
-{
- ADMUX = ((0 << REFS1) | /* AVcc reference */
- (1 << REFS0) | /* AVcc reference */
- (1 << ADLAR) | /* Left-shift results */
- (ADC_CHANNEL_LOW(ADC_CHANNEL))); /* Select channel */
-
- ADCSRB = ADCSRB_INIT | ADC_CHANNEL_HIGH(ADC_CHANNEL);
-
- ADCSRA = ADCSRA_INIT | (1 << ADSC); /* Start conversion */
-}
-
-static void
-adc_init(void)
-{
- ADCSRA = ADCSRA_INIT;
- ADCSRB = ADCSRB_INIT;
- DIDR0 |= (1 << 0);
-}
+#include "ao-bringup.h"
#define AO_STACK_SIZE 128
uint8_t new_stack[512];
int stack_count;
-#define PUSH8(stack, val) (*--(stack) = (val))
+#define PUSH8(stack, val) (*((stack)--) = (val))
#define PUSH16(stack, val) PUSH8(stack, ((uint16_t) (val))); PUSH8(stack, ((uint16_t) (val)) >> 8)
void
init_stack(void (*f) (void))
{
- uint8_t *stack = new_stack + AO_STACK_SIZE;
- uint8_t i;
+ uint8_t *stack = new_stack + AO_STACK_SIZE - 1;
+ uint16_t a;
+ uint8_t h, l;
/* Return address */
- PUSH16(stack, f);
+ a = (uint16_t) f;
+ l = a;
+ h = a >> 8;
+ PUSH8(stack, l);
+ PUSH8(stack, h);
-#if 0
/* Clear register values */
- i = 32;
- while (i--)
+ l = 32;
+ while (l--)
PUSH8(stack, 0);
/* SREG with interrupts enabled */
PUSH8(stack, 0x80);
-#endif
stack_count = stack - new_stack;
+ printf("Function is at %p. Stack[1] is %02x Stack[2] is %02x\n",
+ f, stack[1], stack[2]);
+ printf ("stack_count is %d\n", stack_count);
+ printf ("stack is %p\n", stack);
}
void
switch_stack(void) __attribute__((naked));
+void show_stack(char *s, uint8_t h, uint8_t l)
+{
+ printf ("SP at %s %02x %02x\n", s, h, l);
+}
+
void
switch_stack(void)
{
-#if 0
- uint16_t a;
+ uint8_t *sp = (new_stack + stack_count);
uint8_t l, h;
- a = (uint16_t) function;
- l = a;
- h = a >> 8;
+// for (l = 0; l < AO_STACK_SIZE - stack_count; l++)
+// printf ("stack[%2d] = %2x\n", l, sp[l]);
+ l = new_stack[AO_STACK_SIZE - 1];
+ h = new_stack[AO_STACK_SIZE - 2];
+// printf ("Target return address: h %02x l %02x\n", h, l);
+#if 0
asm("push %0" : : "r" (l));
asm("push %0" : : "r" (h));
asm("ret");
asm("in r0, __SREG__" "\n\t"
"push r0");
#endif
- uint8_t *sp = (new_stack + stack_count);
- uint8_t sp_l, sp_h;
+ uint8_t sp_l, sp_h;
+ static uint8_t reg[34];
sp_l = (uint16_t) sp;
sp_h = ((uint16_t) sp) >> 8;
- asm("out __SP_H__,%0" : : "r" (sp_h) );
- asm("out __SP_L__,%0" : : "r" (sp_l) );
- blink();
-#if 0
- asm("pop r0" "\n\t"
- "out __SREG__, r0");
- asm("pop r0; pop r1; pop r2; pop r3; pop r4");
- asm("pop r5; pop r6; pop r7; pop r8; pop r9");
- asm("pop r10; pop r11; pop r12; pop r13; pop r14");
- asm("pop r15; pop r16; pop r17; pop r18; pop r19");
- asm("pop r20; pop r21; pop r22; pop r23; pop r24");
- asm("pop r25; pop r26; pop r27; pop r28; pop r29");
- asm("pop r30; pop r31");
-#endif
- asm("ret");
+ asm volatile ("out __SP_H__,%0" : : "r" (sp_h) );
+ asm volatile ("out __SP_L__,%0" : : "r" (sp_l) );
+
+ asm volatile ("in %0,__SP_H__" : "=&r" (sp_h));
+ asm volatile ("in %0,__SP_L__" : "=&r" (sp_l));
+ asm volatile("pop r0" "\n\t"
+ "out __SREG__, r0");
+ asm volatile("pop r0" "\n\t"
+ "pop r1" "\n\t"
+ "pop r2" "\n\t"
+ "pop r3" "\n\t"
+ "pop r4");
+ asm volatile("pop r5" "\n\t"
+ "pop r6" "\n\t"
+ "pop r7" "\n\t"
+ "pop r8" "\n\t"
+ "pop r9");
+ asm volatile("pop r10" "\n\t"
+ "pop r11" "\n\t"
+ "pop r12" "\n\t"
+ "pop r13" "\n\t"
+ "pop r14");
+ asm volatile("pop r15" "\n\t"
+ "pop r16" "\n\t"
+ "pop r17" "\n\t"
+ "pop r18" "\n\t"
+ "pop r19");
+ asm volatile("pop r20" "\n\t"
+ "pop r21" "\n\t"
+ "pop r22" "\n\t"
+ "pop r23" "\n\t"
+ "pop r24");
+ asm volatile("pop r25" "\n\t"
+ "pop r26" "\n\t"
+ "pop r27" "\n\t"
+ "pop r28" "\n\t"
+ "pop r29");
+ asm volatile("pop r30" "\n\t"
+ "pop r31");
+ asm volatile ("in %0,__SP_H__" : "=&r" (sp_h));
+ asm volatile ("in %0,__SP_L__" : "=&r" (sp_l));
+ asm volatile ("pop %0" : "=&r" (h));
+ asm volatile ("pop %0" : "=&r" (l));
+ show_stack("before ret", sp_h, sp_l);
+ show_stack("returning to", h, l);
+ asm volatile("push %0" : : "r" (l));
+ asm volatile("push %0" : : "r" (h));
+ asm volatile("ret");
}
void back(void)
void main(void)
{
-#if 0
- clock_init();
- adc_init();
- timer1_init();
- timer0_init();
-#endif
+ ao_bringup_init();
- LEDDDR |= (1 << LEDDDRPIN);
+ printf("starting\n");
init_stack(blink);
switch_stack();
projects / fw / altos / commitdiff