Is the RTOS part of the compiled code?

int main()
{
run_rtos () ; // there's a whole world behind this function and how this world works is described in the OS source files that I compiled together with this main function.
}

/*----------------------------------------------------------------------------
 * CMSIS-RTOS 'main' function template
 *---------------------------------------------------------------------------*/

#define osObjectsPublic                     // define objects in main module
#include "osObjects.h"                      // RTOS object definitions

#include "stm32f10x.h"                  // Device header
#include "GPIO_STM32F10x.h"             // Keil::Device:GPIO

void led_init(void)
{
	GPIO_PinConfigure( GPIOB, 8, GPIO_OUT_PUSH_PULL, GPIO_MODE_OUT50MHZ);
	GPIO_PinConfigure( GPIOB, 9, GPIO_OUT_PUSH_PULL, GPIO_MODE_OUT50MHZ);
}

void job1 (void const *arg) { 
	while (1) {
			GPIO_PinWrite(GPIOB, 8, 0);
			osDelay(500);
			GPIO_PinWrite(GPIOB, 8, 1);
			osDelay(500);
		} 
}
void job2 (void const *arg) { 
	while (1) {
			GPIO_PinWrite(GPIOB, 9, 0);
			osDelay(100);
			GPIO_PinWrite(GPIOB, 9, 1);
			osDelay(100);
		} 
}	
osThreadDef (job1, osPriorityNormal, 1, 0); // Define thread for job1
osThreadDef (job2, osPriorityNormal, 1, 0); // Define thread for job2
/*
 * main: initialize and start the system
 */
int main (void) {
  osKernelInitialize ();                    // initialize CMSIS-RTOS

  // initialize peripherals here

  // create 'thread' functions that start executing,
  // example: tid_name = osThreadCreate (osThread(name), NULL);
  // initialize peripherals here
	led_init();
  // create 'thread' functions that start executing,
  // example: tid_name = osThreadCreate (osThread(name), NULL);

	osThreadCreate (osThread (job1), NULL); // Create and start job1 
	osThreadCreate (osThread (job2), NULL); // Create and start job2	

  osKernelStart ();                         // start thread execution 
	while (1) { 
		osThreadYield (); 
		// Next thread 
		}		
}