in GCC/AVR_AVRDx/port.c [124:138]
BaseType_t xPortStartScheduler( void )
{
/* Setup the hardware to generate the tick. */
prvSetupTimerInterrupt();
/* Restore the context of the first task that is going to run. */
portRESTORE_CONTEXT();
/* Simulate a function call end as generated by the compiler. We will now
* jump to the start of the task the context of which we have just restored. */
asm volatile ( "ret" );
/* Should not get here. */
return pdTRUE;
}