/**
*
* @brief Power saving when idle
*
* If _sys_power_save_flag is non-zero, this routine keeps the system in a low
* power state whenever the kernel is idle. If it is zero, this routine will
* fall through and _k_kernel_idle() will try the next idling mechanism.
*
* @return N/A
*
*/
static void _power_save(void)
{
if (_sys_power_save_flag) {
for (;;) {
irq_lock();
#ifdef CONFIG_ADVANCED_POWER_MANAGEMENT
_sys_power_save_idle(_get_next_timer_expiry());
#else
/*
* nano_cpu_idle() is invoked here directly only if APM
* is disabled. Otherwise the microkernel decides
* either to invoke it or to implement advanced idle
* functionality
*/
nano_cpu_idle();
#endif
}
/*
* Code analyzers may complain that _power_save() uses an
* infinite loop unless we indicate that this is intentional
*/
CODE_UNREACHABLE;
}
}
void idle(void *unused1, void *unused2, void *unused3)
{
ARG_UNUSED(unused1);
ARG_UNUSED(unused2);
ARG_UNUSED(unused3);
#ifdef CONFIG_BOOT_TIME_MEASUREMENT
/* record timestamp when idling begins */
extern uint64_t __idle_tsc;
__idle_tsc = _tsc_read();
#endif
for (;;) {
(void)irq_lock();
_sys_power_save_idle(_get_next_timeout_expiry());
IDLE_YIELD_IF_COOP();
}
}
