/*
 * 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 <arch/cpu.h>
#include <nano_private.h>
#include <misc/printk.h>

/* TODO initialize with sentinel values */
const NANO_ESF _default_esf;


/**
 *
 * @brief Nanokernel fatal error handler
 *
 * This routine is called when a fatal error condition is detected by either
 * hardware or software.
 *
 * The caller is expected to always provide a usable ESF.  In the event that the
 * fatal error does not have a hardware generated ESF, the caller should either
 * create its own or call _Fault instead.
 *
 * @param reason the reason that the handler was called
 * @param pEsf pointer to the exception stack frame
 *
 * @return This function does not return.
 */
FUNC_NORETURN void _NanoFatalErrorHandler(unsigned int reason,
					  const NANO_ESF *esf)
{
	/* STUB TODO: dump out reason for the error and any interesting
	 * info in esf
	 */

	_SysFatalErrorHandler(reason, esf);
}


FUNC_NORETURN void _Fault(void)
{
	/* STUB TODO dump out reason for this exception */

	_NanoFatalErrorHandler(_NANO_ERR_HW_EXCEPTION, &_default_esf);
}

/**
 *
 * @brief Fatal error handler
 *
 * This routine implements the corrective action to be taken when the system
 * detects a fatal error.
 *
 * This sample implementation attempts to abort the current thread and allow
 * the system to continue executing, which may permit the system to continue
 * functioning with degraded capabilities.
 *
 * System designers may wish to enhance or substitute this sample
 * implementation to take other actions, such as logging error (or debug)
 * information to a persistent repository and/or rebooting the system.
 *
 * @param reason the fatal error reason
 * @param pEsf the pointer to the exception stack frame
 *
 * @return This function does not return.
 */
FUNC_NORETURN void _SysFatalErrorHandler(unsigned int reason,
					 const NANO_ESF *esf)
{
	/* STUB TODO try to abort task/fibers like in the x86 implementation */
	printk("Fatal error!\n");

	while (1) {
		/* whee! */
	}
}