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which part of code show kernel

vead

Nov 27, 2011
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Hello everyone
I was reading this link https://teknoman117.wordpress.com/2012/06/13/simple-avr-rtos-c-version-2/ there is program for real time operating system. I don't know which part of program is kernel and which part of program is scheduling. can someone tell me which piece of code show kernel and scheduling ?
Code:
#include <avr/io.h>
#include <avr/interrupt.h>

#include "avr-rtos.h"

struct _avr_rtos_task_attr led_1_attr;
struct _avr_rtos_task_attr led_2_attr;
struct _avr_rtos_task_attr led_3_attr;

uint8_t                    led_1_stack[128];
uint8_t                    led_2_stack[128];
uint8_t                    led_3_stack[128];

void led_task(struct _avr_rtos_task_attr *attr)
{
    // To demonstate the passing of operand to the tasks, use the thread id - 1 as the pin to change
    uint8_t pin = attr->id - 1;
    DDRB |= (1 << pin);
    while(1)
    {
        PORTB |= (1 << pin);
        avr_rtos_task_yield();
        PORTB &= ~(1 << pin);
        avr_rtos_task_yield();
    }
}

int main(void)
{
    // Make ready the RTOS!
    avr_rtos_init();

    // We will be starting three tasks, all use the same function - although they have independent stacks and
    // take their ID - 1 as the pin to toggle

    // LED 1 Task
    led_1_attr.priority = 1;
    led_1_attr.update_interval = (1000 * 8);  // Execute every 1000 ms
    avr_rtos_add_task(&led_task, &led_1_stack[127], &led_1_attr);

    // LED 2 Task
    led_2_attr.priority = 2;
    led_2_attr.update_interval = (500 * 8);  // Execute every 500 ms
    avr_rtos_add_task(&led_task, &led_2_stack[127], &led_2_attr);

    // LED 3 Task
    led_3_attr.priority = 3;
    led_3_attr.update_interval = (250 * 8);  // Execute every 250 ms
    avr_rtos_add_task(&led_task, &led_3_stack[127], &led_3_attr);

    // Set up the timer for interrupts (this program was written to run at 11.0592 MHz.  Finagle with
    // the prescaler settings and the compare match register.  The goal is to have a compare match 8000 times
    // per second
    //
    // interrupts per second = F_CPU / (OCR0A * prescaler)
    //

    TIMSK0 = _BV(OCIE0A);
    TCCR0A = _BV(WGM01);
    OCR0A = 0xAD;
    TCCR0B = _BV(CS01);
    sei();

    while (1)
    {
        // Since this is the thread when there is nothing to do, and we don't have anything to do,
        // just call thread yield.  Though we could do something useful....
        //avr_rtos_task_yield();    // cause a lock up, check in simulator later....
    }

    // return control to libgcc.S
    return 0;
}

ISR(TIMER0_COMPA_vect)
{
    // Only call the context switcher every 8'th interrupt (1 KHz)
    if(!(avr_rtos_tick() % 8))
        avr_rtos_isr();
}
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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I would say that loosely, it's a combination of user code and a scheduler. There is no OS.
 

vead

Nov 27, 2011
473
Joined
Nov 27, 2011
Messages
473
I would say that loosely, it's a combination of user code and a scheduler. There is no OS.
does anyone have RTOS code or link which show part of kernel and scheduling. I am searching on internet from long time . actually I want to see whole program for RTOS. but I am not getting suitable example.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
does anyone have RTOS code or link which show part of kernel and scheduling. I am searching on internet from long time . actually I want to see whole program for RTOS. but I am not getting suitable example.

Here you go. (10 seconds from reading the question to googling, to posting the link.)
 
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