RTOS implementation with in-line assembly - EE.StackExchange

/*
 * File:   main.c
 * Author: abdullah
 *
 * Created on 10 Haziran 2012 Pazar, 14:43
 */
#include <xc.h> // Include the header file needed by the compiler
#include "RTOS.h" // Include the header for co-operative RTOS.
__CONFIG(FOSC_INTOSCIO & WDTE_OFF & PWRTE_ON & MCLRE_OFF & CP_OFF & IOSCFS_4MHZ & BOREN_ON);

unsigned char OS_currentTask; // This register holds the current task's place in the array OS_tasks
unsigned char OS_tasks[4]; // This array holds PCL and PCLATH for tasks. This array will have..
//                            .. (number of tasks)*2 elements, since every task occupies 2 places.

void fTask1(void); // Prototype the function for task1.
void fTask2(void); // Prototype the function for task2.

void main(void) @ 0x0001
{
    TRISA = 0; // Set all of the PORTA pins as outputs.
    TRISC = 0; // Set all of the PORTC pins as outputs.
    ANSEL = 0; // Set all of the analog input pins as digital i/o.
    PORTA = 0; // Clear PORTA bits.
    PORTC = 0; // Clear PORTC bits.

    OS_currentTask = 0; // Current task is first task.
    fTask1(); // Call task to initialize it.
    OS_currentTask += 2; // Increment task pointer by two since every task occupies 2 places in the array.
    fTask2(); // Call task to initialize it.
    OS_runTasks(4); // Run the tasks in order. The argument of this macro takes is: (Number of tasks) * 2
}

void fTask1(void)
{
    OS_initializeTask(); // Initialize the task so that task runner can get its ingredients.
    while (1)
    {
        PORTC = 0xAA;
        OS_yield(); // Yield CPU to other tasks.
        PORTC = 0x55;
        OS_yield(); // Yield CPU to other tasks.
    }
}

void fTask2(void)
{
    OS_initializeTask(); // Initialize the task so that task runner can get its ingredients.
    while (1)
    {
        PORTC = 0xFF;
        OS_yield(); // Yield CPU to other tasks.
        PORTC = 0x00;
        OS_yield(); // Yield CPU to other tasks.
    }
}