Colony - / - Diff - Robotics Club

Revision 1574

      * Based on avrOS and 18348 Lab9 code
      **/
     #include <avr/interrupt.h>
     #include <util/delay.h>
     #include <avr/interrupt.h>
     #include <util/delay.h>
     #include "scheduler.h"
     #define DEBUG
     #ifdef DEBUG
     #include <serial.h>
     #endif //DEBUG
     #endif
     static uint8_t STACK[MAXTASKS + 1][STACKSIZE];
     static uint8_t nactive_tasks = 1;
-...
+    {
     	void (*exec)(void);
     	uint8_t* sp;
     	char running;
     	uint16_t period; //Interval in clock cycles.
     	uint32_t next;
     	char running;
     } PCB_t;
     PCB_t PCB[MAXTASKS + 1];
-...
     	//Enable Output Compare A Interrupt. (Begins immediately).
       	ETIMSK |= _BV(OCIE3A);
     #ifdef DEBUG
     	usb_init();
     #endif //DEBUG
     	sei();
+    }
     static void task_terminate(void) {
     #ifdef DEBUG
     	usb_puts("In task terminate!.\n\r");
     #endif //DEBUG
     	PCB[current_task].running = 0;
     	yield();
+    }
-...
     	PCB[nactive_tasks].exec = exec;
     	PCB[nactive_tasks].period = period;
     	cli();
     	PCB[nactive_tasks].next = current_time + period;
     	sei();
     	PCB[nactive_tasks].running = 0;
     	//Don't need to initialize SP, it will get done later.
-...
     //I need a timer to do the rest.  Thinking about stealing it from rtc.
     SIGNAL(TIMER3_COMPA_vect) {
     	static uint8_t task_i = 1;
     	volatile uint8_t** sploc;
     	volatile uint8_t* sp;
     	uint8_t i;
     #ifdef DEBUG
     	char test_buf[128];
     #endif //DEBUG
     	//Store sp.
     	sploc = &(PCB[current_task].sp);
     	sp = (uint8_t*)&(PCB[current_task].sp);
     	asm volatile( \
     		"in r0, __SP_L__ \n" \
     	   	"st %a0+, r0 \n" \
     	    "in r0, __SP_H__ \n" \
     		"st %a0, r0 \n"  : : "e" (sploc));
     		"st %a0, r0 \n"  : : "e" (sp));
     #ifdef DEBUG
     	sprintf(test_buf, "current_task = %d, current_time = %d, sp = %x\n\r", current_task, current_time, sploc);
     	usb_puts(test_buf);
     #endif //DEBUG
     	//The current task may no longer be running when we exit.
     	PCB[current_task].running = 0;
     	//Keep track of the number of 1/16 second's that have passed.
     	current_time++;
-...
     	//Loop over registered tasks, like in round robin order.
     	for(i = nactive_tasks - 1; i > 0; i--) {
     		//Launch a new task if it is due to run.
     		if(	!PCB[task_i].running
     		  && PCB[task_i].next <= current_time) {
     			task_i++;
     			current_task = task_i;
     			PCB[task_i].next += PCB[task_i].period;
     			PCB[current_task].next += PCB[current_task].period;
     			PCB[current_task].running = 1;
     			task_i++;
     			if(task_i >= nactive_tasks)
     				task_i = 1;
     			/***** create launch stack ***/
     #ifdef DEBUG
     			usb_puts("Switching tasks..... (cross fingers)\n\r");
     #endif //DEBUG
     			sp = &(STACK[task_i][STACKSIZE - 1]);
     			sp = (void*)((uint16_t)&STACK[current_task][STACKSIZE - 1]);
     			//Put task terminate  and the task to execute on the stack.
     			*(sp--) = (uint8_t)(uint16_t) task_terminate;
     			*(sp--) = (uint8_t)(uint16_t) task_terminate >> 8;
     			*(sp--) = (uint8_t)(uint16_t) PCB[nactive_tasks].exec;
     			*(sp--) = (uint8_t)(uint16_t) PCB[nactive_tasks].exec >> 8;
     			*(sp--) = (uint8_t)(uint16_t)*task_terminate;
     			*(sp--) = (uint8_t)((uint16_t)*task_terminate >> 8);
     			*(sp--) = (uint8_t)(uint16_t)PCB[current_task].exec;
     			*(sp--) = (uint8_t)((uint16_t)PCB[current_task].exec >> 8);
     			//The current state of the registers is what the tasks will
     			//see on entry (shouldn't matter).
-...
     				"out __SP_L__, %A0 \n" \
     				"out __SP_H__, %B0 \n" : : "d" (sp));
     #ifdef DEBUG
     			sprintf(test_buf, "Switching tasks,  sp = %x\n\r", sp);
     			usb_puts(test_buf);
     #endif //DEBUG
     	 		/* start process and enable interrupts */
     	 		asm volatile("reti \n");
     			break;
+    		}
     		//Continue an old task.
     		if(PCB[task_i].running) {
     		if(PCB[task_i].running == 1) {
     			current_task = task_i;
     			//Reset the stack pointer.
     			sp = PCB[current_task].sp;
     			asm volatile( \
     				"out __SP_L__, %A0 \n" \
     				"out __SP_H__, %B0 \n" : : "d" (sp));
     			task_i++;
     			if(task_i >= nactive_tasks)
     				task_i = 1;
     			break;
+    		}
     		//Loop back to 1 if necessary.
     		task_i++;
     		if(task_i >= nactive_tasks)
     		if(task_i >= nactive_tasks)
     			task_i = 1;
+    	}
     	//If no task was selected to run, go to main
     	if(i == 0) {
     #ifdef DEBUG
     		usb_puts("Resetting main.\n\r");
     #endif //DEBUG
     		//Set the SP to the original stack.
     		sp = PCB[current_task].sp;
     		asm volatile( \
     			"out __SP_L__, %A0 \n" \
     			"out __SP_H__, %B0 \n" : : "d" (sp));
     	if(i == 0)
     		current_task = 0;
+    	}
     	//Reset the stack pointer.
     	sp = PCB[current_task].sp;
     	asm volatile( \
     		"out __SP_L__, %A0 \n" \
     		"out __SP_H__, %B0 \n" : : "d" (sp));
     	//Set the running task.*/
     	PCB[current_task].running = 1;

     #define _SCHEDULER_H_
     #define STACKSIZE 128
     #define MAXTASKS 3
     #define MAXTASKS 4
     #include <stdint.h>

     	usb_puts("Oh no!!! Reset!!\n\r");
     	scheduler_init();
     	register_task(task0, 22);
     	//register_task(task1, 2);
     	//register_task(task2, 3);
     	register_task(task0, 48);
     	register_task(task1, 20);
     	register_task(task2, 80);
     	while (1) {
     		//usb_puti(time_now());
     		usb_puts("main\n\r");
     		delay_ms(200);
     		delay_ms(20);
+    	}
     	return 0;
+    }
     void task0() {
     	sei();
     	usb_puts("0\n\r");
     	cli();
     	int i = 0;
     	while(1) {
     		usb_puts("Task 0-");
     		usb_puti(i++);
     		usb_puts("\n\r");
     		delay_ms(20);
+    	}
+    }
     void task1() {
     	cli();
     	usb_puts("Hello from task 1\n\r");
     	sei();
     	usb_puts("1\n\r");
     	cli();
+    }
     void task2() {
     	cli();
     	usb_puts("Hello from task 2\n\r");
     	sei();
     	usb_puts("2\n\r");
     	cli();
+    }

     COLONYROOT := ..
     # Target file name (without extension).
     TARGET = main
     TARGET=main
     # Uncomment this to use the wireless library
     USE_WIRELESS = 1
     # com1 = serial port. Use lpt1 to connect to parallel port.
     AVRDUDE_PORT = $(shell if uname -s |grep -i w32 >/dev/null; then echo 'COM4:'; else echo '/dev/ttyUSB0'; fi)
     AVRDUDE_PORT = /dev/tty.usbserial-A4001hAG
     else
     COLONYROOT := ../$(COLONYROOT)
     endif
     include $(COLONYROOT)/Makefile
     include $(COLONYROOT)/Makefile

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