/*******************************************************************************
  MPLAB Harmony Exceptions Source File

  File Name:
    exceptions.c

  Summary:
    This file contains a function which overrides the default _weak_ exception
    handler provided by the XC32 compiler.

  Description:
    This file redefines the default _weak_  exception handler with a more debug
    friendly one. If an unexpected exception occurs the code will stop in a
    while(1) loop.  The debugger can be halted and two variables _excep_code and
    _except_addr can be examined to determine the cause and address where the
    exception occurred.
 *******************************************************************************/

// DOM-IGNORE-BEGIN
/*******************************************************************************
* Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries.
*
* Subject to your compliance with these terms, you may use Microchip software
* and any derivatives exclusively with Microchip products. It is your
* responsibility to comply with third party license terms applicable to your
* use of third party software (including open source software) that may
* accompany Microchip software.
*
* THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, WHETHER
* EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, INCLUDING ANY IMPLIED
* WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE,
* INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND
* WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS
* BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE
* FULLEST EXTENT ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN
* ANY WAY RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY,
* THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
*******************************************************************************/
// DOM-IGNORE-END

// *****************************************************************************
// *****************************************************************************
// Section: Included Files
// *****************************************************************************
// *****************************************************************************
#include "configuration.h"
#include "device.h"
#include "definitions.h"
#include <stdio.h>


// *****************************************************************************
// *****************************************************************************
// Section: Global Data Definitions
// *****************************************************************************
// *****************************************************************************

/*******************************************************************************
  Exception Reason Data

  <editor-fold defaultstate="expanded" desc="Exception Reason Data">

  Remarks:
    These global static items are used instead of local variables in the
    _general_exception_handler function because the stack may not be available
    if an exception has occured.
*/

/* Address of instruction that caused the exception. */
static unsigned int _excep_addr;

/* Enum identifying the cause */
typedef enum {
    EXCEP_IRQ      =  0, // interrupt
    EXCEP_AdEL     =  4, // address error exception (load or ifetch)
    EXCEP_AdES     =  5, // address error exception (store)
    EXCEP_IBE      =  6, // bus error (ifetch)
    EXCEP_DBE      =  7, // bus error (load/store)
    EXCEP_Sys      =  8, // syscall
    EXCEP_Bp       =  9, // breakpoint
    EXCEP_RI       = 10, // reserved instruction
    EXCEP_CpU      = 11, // coprocessor unusable
    EXCEP_Overflow = 12, // arithmetic overflow
    EXCEP_Trap     = 13, // trap (possible divide by zero)
    EXCEP_IS1      = 16, // implementation specfic 1
    EXCEP_CEU      = 17, // CorExtend Unuseable
    EXCEP_C2E      = 18, // coprocessor 2
} excep_code;

/* Code identifying the cause of the exception (CP0 Cause register). */
static excep_code _excep_code;

// </editor-fold>

/*******************************************************************************
  Function:
    void _general_exception_handler ( void )

  Description:
    A general exception is any non-interrupt exception which occurs during program
    execution outside of bootstrap code.

  Remarks:
    Refer to the XC32 User's Guide for additional information.
 */

void __attribute__((noreturn)) _general_exception_handler ( void )
{
    /* Mask off the ExcCode Field from the Cause Register
    Refer to the MIPs Software User's manual */
    _excep_code = (_CP0_GET_CAUSE() & 0x0000007C) >> 2;
    _excep_addr = _CP0_GET_EPC();

    while (1)
    {
        #if defined(__DEBUG) || defined(__DEBUG_D) && defined(__XC32)
            __builtin_software_breakpoint();
        #endif
    }
}

/*******************************************************************************
  Function:
    void _bootstrap_exception_handler ( void )

  Description:
    A bootstrap exception is any exception which occurs while bootstrap code is
    running (STATUS.BEV bit is 1).

  Remarks:
    Refer to the XC32 User's Guide for additional information.
 */

void __attribute__((noreturn)) _bootstrap_exception_handler(void)
{
    /* Mask off the ExcCode Field from the Cause Register
    Refer to the MIPs Software User's manual */
    _excep_code = (_CP0_GET_CAUSE() & 0x0000007C) >> 2;
    _excep_addr = _CP0_GET_EPC();

    while (1)
    {
        #if defined(__DEBUG) || defined(__DEBUG_D) && defined(__XC32)
            __builtin_software_breakpoint();
        #endif
    }
}
/*******************************************************************************
 End of File
*/
