zephyr/arch/nios2/core/cpu_idle.c

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/*
* Copyright (c) 2016 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <nanokernel.h>
#include <nano_private.h>
/**
*
* @brief Power save idle routine
*
* This function will be called by the nanokernel idle loop or possibly within
* an implementation of _sys_power_save_idle in the microkernel when the
* '_sys_power_save_flag' variable is non-zero.
*
* @return N/A
*/
void nano_cpu_idle(void)
{
/* STUB */
}
/**
*
* @brief Atomically re-enable interrupts and enter low power mode
*
* This function is utilized by the nanokernel object "wait" APIs for tasks,
* e.g. nano_task_lifo_get(), nano_task_sem_take(),
* nano_task_stack_pop(), and nano_task_fifo_get().
*
* INTERNAL
* The requirements for nano_cpu_atomic_idle() are as follows:
* 1) The enablement of interrupts and entering a low-power mode needs to be
* atomic, i.e. there should be no period of time where interrupts are
* enabled before the processor enters a low-power mode. See the comments
* in nano_task_lifo_get(), for example, of the race condition that
* occurs if this requirement is not met.
*
* 2) After waking up from the low-power mode, the interrupt lockout state
* must be restored as indicated in the 'imask' input parameter.
*
* @return N/A
*/
void nano_cpu_atomic_idle(unsigned int key)
{
/* STUB */
}