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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chsys.c
* @brief System related code.
*
* @addtogroup system
* @details System related APIs and services:
* - Initialization.
* - Locks.
* - Interrupt Handling.
* - Power Management.
* - Abnormal Termination.
* .
* @{
*/
#include "ch.h"
/**
* @brief Idle thread working area.
* @see IDLE_THREAD_STACK_SIZE
*/
WORKING_AREA(_idle_thread_wa, IDLE_THREAD_STACK_SIZE);
/**
* @brief This function implements the idle thread infinite loop.
* @details The function puts the processor in the lowest power mode capable
* to serve interrupts.<br>
* The priority is internally set to the minimum system value so
* that this thread is executed only if there are no other ready
* threads in the system.
*
* @param[in] p the thread parameter, unused in this scenario
*/
void _idle_thread(void *p) {
(void)p;
while (TRUE) {
port_wait_for_interrupt();
IDLE_LOOP_HOOK();
}
}
/**
* @brief ChibiOS/RT initialization.
* @details After executing this function the current instructions stream
* becomes the main thread.
* @note Interrupts should be still disabled when @p chSysInit() is invoked
* and are internally enabled.
* @note The main thread is created with priority @p NORMALPRIO.
*/
void chSysInit(void) {
static Thread mainthread;
port_init();
scheduler_init();
vt_init();
#if CH_USE_MEMCORE
core_init();
#endif
#if CH_USE_HEAP
heap_init();
#endif
#if CH_DBG_ENABLE_TRACE
trace_init();
#endif
/* Now this instructions flow becomes the main thread.*/
setcurrp(init_thread(&mainthread, NORMALPRIO));
currp->p_state = THD_STATE_CURRENT;
chSysEnable();
/* This thread has the lowest priority in the system, its role is just to
serve interrupts in its context while keeping the lowest energy saving
mode compatible with the system status.*/
chThdCreateStatic(_idle_thread_wa, sizeof(_idle_thread_wa), IDLEPRIO,
(tfunc_t)_idle_thread, NULL);
}
/**
* @brief Handles time ticks for round robin preemption and timer increments.
* @details Decrements the remaining time quantum of the running thread
* and preempts it when the quantum is used up. Increments system
* time and manages the timers.
*
* @note The frequency of the timer determines the system tick granularity
* and, together with the @p CH_TIME_QUANTUM macro, the round robin
* interval.
*/
void chSysTimerHandlerI(void) {
#if CH_TIME_QUANTUM > 0
/* Running thread has not used up quantum yet? */
if (rlist.r_preempt > 0)
/* Decrement remaining quantum.*/
rlist.r_preempt--;
#endif
#if CH_DBG_THREADS_PROFILING
currp->p_time++;
#endif
chVTDoTickI();
#if defined(SYSTEM_TICK_EVENT_HOOK)
SYSTEM_TICK_EVENT_HOOK();
#endif
}
#if CH_USE_NESTED_LOCKS && !CH_OPTIMIZE_SPEED
void chSysLock(void) {
chDbgAssert(currp->p_locks >= 0,
"chSysLock(), #1",
"negative nesting counter");
if (currp->p_locks++ == 0)
port_lock();
}
void chSysUnlock(void) {
chDbgAssert(currp->p_locks > 0,
"chSysUnlock(), #1",
"non-positive nesting counter");
if (--currp->p_locks == 0)
port_unlock();
}
#endif /* CH_USE_NESTED_LOCKS && !CH_OPTIMIZE_SPEED */
/** @} */
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