git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1073 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 129 insertions, 0 deletions

diff --git a/os/kernel/src/chsys.c b/os/kernel/src/chsys.c
new file mode 100644
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+++ b/os/kernel/src/chsys.c
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+/*
+    ChibiOS/RT - Copyright (C) 2006-2007 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
+ * @{
+ */
+
+#include <ch.h>
+
+static 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
+ */
+static void idle_thread(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_HEAP
+  heap_init();
+#endif
+#if CH_DBG_ENABLE_TRACE
+  trace_init();
+#endif
+
+  /*
+   * Now this instructions flow becomes the main thread.
+   */
+  (currp = init_thread(&mainthread, NORMALPRIO))->p_state = PRCURR;
+  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_USE_ROUNDROBIN
+  /* 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 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 */
+
+/** @} */