/*
    FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.

    FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT 
    http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS tutorial books are available in pdf and paperback.        *
     *    Complete, revised, and edited pdf reference manuals are also       *
     *    available.                                                         *
     *                                                                       *
     *    Purchasing FreeRTOS documentation will not only help you, by       *
     *    ensuring you get running as quickly as possible and with an        *
     *    in-depth knowledge of how to use FreeRTOS, it will also help       *
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     *    professional grade, cross platform, de facto standard solutions    *
     *    for microcontrollers - completely free of charge!                  *
     *                                                                       *
     *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
     *                                                                       *
     *    Thank you for using FreeRTOS, and thank you for your support!      *
     *                                                                       *
    ***************************************************************************


    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
    >>>NOTE<<< The modification to the GPL is included to allow you to
    distribute a combined work that includes FreeRTOS without being obliged to
    provide the source code for proprietary components outside of the FreeRTOS
    kernel.  FreeRTOS 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 and the FreeRTOS license exception along with FreeRTOS; if not it
    can be viewed here: http://www.freertos.org/a00114.html and also obtained
    by writing to Richard Barry, contact details for whom are available on the
    FreeRTOS WEB site.

    1 tab == 4 spaces!
    
    ***************************************************************************
     *                                                                       *
     *    Having a problem?  Start by reading the FAQ "My application does   *
     *    not run, what could be wrong?"                                     *
     *                                                                       *
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    ***************************************************************************

    
    http://www.FreeRTOS.org - Documentation, training, latest versions, license 
    and contact details.  
    
    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool.

    Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell 
    the code with commercial support, indemnification, and middleware, under 
    the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also
    provide a safety engineered and independently SIL3 certified version under 
    the SafeRTOS brand: http://www.SafeRTOS.com.
*/

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"

/* Hardware includes. */
#include <microblaze_exceptions_i.h>
#include <microblaze_exceptions_g.h>

/* The Xilinx library defined exception entry point stacks a number of
registers.  These definitions are offsets from the stack pointer to the various
stacked register values. */
#define portexR3_STACK_OFFSET	4
#define portexR4_STACK_OFFSET	5
#define portexR5_STACK_OFFSET	6
#define portexR6_STACK_OFFSET	7
#define portexR7_STACK_OFFSET	8
#define portexR8_STACK_OFFSET	9
#define portexR9_STACK_OFFSET	10
#define portexR10_STACK_OFFSET	11
#define portexR11_STACK_OFFSET	12
#define portexR12_STACK_OFFSET	13
#define portexR15_STACK_OFFSET	16
#define portexR18_STACK_OFFSET  19
#define portexMSR_STACK_OFFSET	20
#define portexR19_STACK_OFFSET  -1

/* This is defined to equal the size, in bytes, of the stack frame generated by
the Xilinx standard library exception entry point.  It is required to determine
the stack pointer value prior to the exception being entered. */
#define portexASM_HANDLER_STACK_FRAME_SIZE 84UL

/* The number of bytes a MicroBlaze instruction consumes. */
#define portexINSTRUCTION_SIZE	4

/* Exclude this entire file if the MicroBlaze is not configured to handle
exceptions, or the application defined configuration constant
configINSTALL_EXCEPTION_HANDLERS is not set to 1. */
#if ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 )

/* This variable is set in the exception entry code, before
vPortExceptionHandler is called. */
unsigned long *pulStackPointerOnFunctionEntry = NULL;

/* This is the structure that is filled with the MicroBlaze context as it
existed immediately prior to the exception occurrence.  A pointer to this
structure is passed into the vApplicationExceptionRegisterDump() callback
function, if one is defined. */
static xPortRegisterDump xRegisterDump;

/* This is the FreeRTOS exception handler that is installed for all exception
types.  It is called from vPortExceptionHanlderEntry() - which is itself defined
in portasm.S. */
void vPortExceptionHandler( void *pvExceptionID );
extern void vPortExceptionHandlerEntry( void *pvExceptionID );

/*-----------------------------------------------------------*/

/* vApplicationExceptionRegisterDump() is a callback function that the 
application can optionally define to receive a populated xPortRegisterDump
structure.  If the application chooses not to define a version of 
vApplicationExceptionRegisterDump() then this weekly defined default 
implementation will be called instead. */
extern void vApplicationExceptionRegisterDump( xPortRegisterDump *xRegisterDump ) __attribute__((weak));
void vApplicationExceptionRegisterDump( xPortRegisterDump *xRegisterDump )
{
	( void ) xRegisterDump;

	for( ;; )
	{
		portNOP();
	}
}
/*-----------------------------------------------------------*/

void vPortExceptionHandler( void *pvExceptionID )
{
extern void *pxCurrentTCB;

	/* Fill an xPortRegisterDump structure with the MicroBlaze context as it
	was immediately before the exception occurrence. */
	
	/* First fill in the name and handle of the task that was in the Running 
	state when the exception occurred. */
	xRegisterDump.xCurrentTaskHandle = pxCurrentTCB;
	xRegisterDump.pcCurrentTaskName = pcTaskGetTaskName( NULL );

	configASSERT( pulStackPointerOnFunctionEntry );

	/* Obtain the values of registers that were stacked prior to this function
	being called, and may have changed since they were stacked. */
	xRegisterDump.ulR3 = pulStackPointerOnFunctionEntry[ portexR3_STACK_OFFSET ];
	xRegisterDump.ulR4 = pulStackPointerOnFunctionEntry[ portexR4_STACK_OFFSET ];
	xRegisterDump.ulR5 = pulStackPointerOnFunctionEntry[ portexR5_STACK_OFFSET ];
	xRegisterDump.ulR6 = pulStackPointerOnFunctionEntry[ portexR6_STACK_OFFSET ];
	xRegisterDump.ulR7 = pulStackPointerOnFunctionEntry[ portexR7_STACK_OFFSET ];
	xRegisterDump.ulR8 = pulStackPointerOnFunctionEntry[ portexR8_STACK_OFFSET ];
	xRegisterDump.ulR9 = pulStackPointerOnFunctionEntry[ portexR9_STACK_OFFSET ];
	xRegisterDump.ulR10 = pulStackPointerOnFunctionEntry[ portexR10_STACK_OFFSET ];
	xRegisterDump.ulR11 = pulStackPointerOnFunctionEntry[ portexR11_STACK_OFFSET ];
	xRegisterDump.ulR12 = pulStackPointerOnFunctionEntry[ portexR12_STACK_OFFSET ];
	xRegisterDump.ulR15_return_address_from_subroutine = pulStackPointerOnFunctionEntry[ portexR15_STACK_OFFSET ];
	xRegisterDump.ulR18 = pulStackPointerOnFunctionEntry[ portexR18_STACK_OFFSET ];
	xRegisterDump.ulR19 = pulStackPointerOnFunctionEntry[ portexR19_STACK_OFFSET ];
	xRegisterDump.ulMSR = pulStackPointerOnFunctionEntry[ portexMSR_STACK_OFFSET ];
	
	/* Obtain the value of all other registers. */
	xRegisterDump.ulR2_small_data_area = mfgpr( R2 );
	xRegisterDump.ulR13_read_write_small_data_area = mfgpr( R13 );
	xRegisterDump.ulR14_return_address_from_interrupt = mfgpr( R14 );
	xRegisterDump.ulR16_return_address_from_trap = mfgpr( R16 );
	xRegisterDump.ulR17_return_address_from_exceptions = mfgpr( R17 );
	xRegisterDump.ulR20 = mfgpr( R20 );
	xRegisterDump.ulR21 = mfgpr( R21 );
	xRegisterDump.ulR22 = mfgpr( R22 );
	xRegisterDump.ulR23 = mfgpr( R23 );
	xRegisterDump.ulR24 = mfgpr( R24 );
	xRegisterDump.ulR25 = mfgpr( R25 );
	xRegisterDump.ulR26 = mfgpr( R26 );
	xRegisterDump.ulR27 = mfgpr( R27 );
	xRegisterDump.ulR28 = mfgpr( R28 );
	xRegisterDump.ulR29 = mfgpr( R29 );
	xRegisterDump.ulR30 = mfgpr( R30 );
	xRegisterDump.ulR31 = mfgpr( R31 );
	xRegisterDump.ulR1_SP = ( ( unsigned long ) pulStackPointerOnFunctionEntry ) + portexASM_HANDLER_STACK_FRAME_SIZE;
	xRegisterDump.ulEAR = mfear();
	xRegisterDump.ulESR = mfesr();
	xRegisterDump.ulEDR = mfedr();
	
	/* Move the saved program counter back to the instruction that was executed
	when the exception occurred.  This is only valid for certain types of
	exception. */
	xRegisterDump.ulPC = xRegisterDump.ulR17_return_address_from_exceptions - portexINSTRUCTION_SIZE;

	#if XPAR_MICROBLAZE_0_USE_FPU == 1
	{
		xRegisterDump.ulFSR = mffsr();
	}
	#else
	{
		xRegisterDump.ulFSR = 0UL;
	}
	#endif

	/* Also fill in a string that describes what type of exception this is.
	The string uses the same ID names as defined in the MicroBlaze standard
	library exception header files. */
	switch( ( unsigned long ) pvExceptionID )
	{
		case XEXC_ID_FSL :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_FSL";
				break;

		case XEXC_ID_UNALIGNED_ACCESS :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_UNALIGNED_ACCESS";
				break;

		case XEXC_ID_ILLEGAL_OPCODE :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_ILLEGAL_OPCODE";
				break;

		case XEXC_ID_M_AXI_I_EXCEPTION :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_M_AXI_I_EXCEPTION or XEXC_ID_IPLB_EXCEPTION";
				break;

		case XEXC_ID_M_AXI_D_EXCEPTION :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_M_AXI_D_EXCEPTION or XEXC_ID_DPLB_EXCEPTION";
				break;

		case XEXC_ID_DIV_BY_ZERO :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_DIV_BY_ZERO";
				break;

		case XEXC_ID_STACK_VIOLATION :
				xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_STACK_VIOLATION or XEXC_ID_MMU";
				break;

		#if XPAR_MICROBLAZE_0_USE_FPU == 1

			case XEXC_ID_FPU :
						xRegisterDump.pcExceptionCause = ( signed char * const ) "XEXC_ID_FPU see ulFSR value";
						break;

		#endif /* XPAR_MICROBLAZE_0_USE_FPU */
	}

	/* vApplicationExceptionRegisterDump() is a callback function that the 
	application can optionally define to receive the populated xPortRegisterDump
	structure.  If the application chooses not to define a version of 
	vApplicationExceptionRegisterDump() then the weekly defined default 
	implementation within this file will be called instead. */
	vApplicationExceptionRegisterDump( &xRegisterDump );

	/* Must not attempt to leave this function! */
	for( ;; )
	{
		portNOP();
	}
}
/*-----------------------------------------------------------*/

void vPortExceptionsInstallHandlers( void )
{
static unsigned long ulHandlersAlreadyInstalled = pdFALSE;

	if( ulHandlersAlreadyInstalled == pdFALSE )
	{
		ulHandlersAlreadyInstalled = pdTRUE;

		#if XPAR_MICROBLAZE_0_UNALIGNED_EXCEPTIONS == 1
			microblaze_register_exception_handler( XEXC_ID_UNALIGNED_ACCESS, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_UNALIGNED_ACCESS );
		#endif /* XPAR_MICROBLAZE_0_UNALIGNED_EXCEPTIONS*/

		#if XPAR_MICROBLAZE_0_ILL_OPCODE_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_ILLEGAL_OPCODE, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_ILLEGAL_OPCODE );
		#endif /* XPAR_MICROBLAZE_0_ILL_OPCODE_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_M_AXI_I_BUS_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_M_AXI_I_EXCEPTION, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_M_AXI_I_EXCEPTION );
		#endif /* XPAR_MICROBLAZE_0_M_AXI_I_BUS_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_M_AXI_D_BUS_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_M_AXI_D_EXCEPTION, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_M_AXI_D_EXCEPTION );
		#endif /* XPAR_MICROBLAZE_0_M_AXI_D_BUS_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_IPLB_BUS_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_IPLB_EXCEPTION, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_IPLB_EXCEPTION );
		#endif /* XPAR_MICROBLAZE_0_IPLB_BUS_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_DPLB_BUS_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_DPLB_EXCEPTION, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_DPLB_EXCEPTION );
		#endif /* XPAR_MICROBLAZE_0_DPLB_BUS_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_DIV_ZERO_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_DIV_BY_ZERO, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_DIV_BY_ZERO );
		#endif /* XPAR_MICROBLAZE_0_DIV_ZERO_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_FPU_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_FPU, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_FPU );
		#endif /* XPAR_MICROBLAZE_0_FPU_EXCEPTION*/

		#if XPAR_MICROBLAZE_0_FSL_EXCEPTION == 1
			microblaze_register_exception_handler( XEXC_ID_FSL, vPortExceptionHandlerEntry, ( void * ) XEXC_ID_FSL );
		#endif /* XPAR_MICROBLAZE_0_FSL_EXCEPTION*/
	}
}

/* Exclude the entire file if the MicroBlaze is not configured to handle
exceptions, or the application defined configuration item 
configINSTALL_EXCEPTION_HANDLERS is not set to 1. */
#endif /* ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 ) */