/*
 * FreeRTOS Kernel <DEVELOPMENT BRANCH>
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 * 1 tab == 4 spaces!
 */

/* Kernel includes. */
#include "FreeRTOS.h"

/* Machine includes */
#include <tc1782.h>
#include <machine/intrinsics.h>
#include <machine/cint.h>
/*---------------------------------------------------------------------------*/

/*
 * This reference is required by the Save/Restore Context Macros.
 */
extern volatile uint32_t *pxCurrentTCB;
/*-----------------------------------------------------------*/

/*
 * This file contains base definitions for all of the possible traps in the system.
 * It is suggested to provide implementations for all of the traps but for
 * the time being they simply trigger a DEBUG instruction so that it is easy
 * to see what caused a particular trap.
 *
 * Trap Class 6, the SYSCALL, is used exclusively by the operating system.
 */

/* The Trap Classes. */
#define portMMU_TRAP										0
#define portIPT_TRAP										1
#define portIE_TRAP											2
#define portCM_TRAP											3
#define portSBP_TRAP										4
#define portASSERT_TRAP										5
#define portNMI_TRAP										7

/* MMU Trap Identifications. */
#define portTIN_MMU_VIRTUAL_ADDRESS_FILL					0
#define portTIN_MMU_VIRTUAL_ADDRESS_PROTECTION				1

/* Internal Protection Trap Identifications. */
#define portTIN_IPT_PRIVILIGED_INSTRUCTION					1
#define portTIN_IPT_MEMORY_PROTECTION_READ					2
#define portTIN_IPT_MEMORY_PROTECTION_WRITE					3
#define portTIN_IPT_MEMORY_PROTECTION_EXECUTION				4
#define portTIN_IPT_MEMORY_PROTECTION_PERIPHERAL_ACCESS		5
#define portTIN_IPT_MEMORY_PROTECTION_NULL_ADDRESS			6
#define portTIN_IPT_MEMORY_PROTECTION_GLOBAL_REGISTER_WRITE_PROTECTION	7

/* Instruction Error Trap Identifications. */
#define portTIN_IE_ILLEGAL_OPCODE							1
#define portTIN_IE_UNIMPLEMENTED_OPCODE						2
#define portTIN_IE_INVALID_OPERAND							3
#define portTIN_IE_DATA_ADDRESS_ALIGNMENT					4
#define portTIN_IE_INVALID_LOCAL_MEMORY_ADDRESS				5

/* Context Management Trap Identifications. */
#define portTIN_CM_FREE_CONTEXT_LIST_DEPLETION				1
#define portTIN_CM_CALL_DEPTH_OVERFLOW						2
#define portTIN_CM_CALL_DEPTH_UNDEFLOW						3
#define portTIN_CM_FREE_CONTEXT_LIST_UNDERFLOW				4
#define portTIN_CM_CALL_STACK_UNDERFLOW						5
#define portTIN_CM_CONTEXT_TYPE								6
#define portTIN_CM_NESTING_ERROR							7

/* System Bus and Peripherals Trap Identifications. */
#define portTIN_SBP_PROGRAM_FETCH_SYNCHRONOUS_ERROR			1
#define portTIN_SBP_DATA_ACCESS_SYNCHRONOUS_ERROR			2
#define portTIN_SBP_DATA_ACCESS_ASYNCHRONOUS_ERROR			3
#define portTIN_SBP_COPROCESSOR_TRAP_ASYNCHRONOUS_ERROR		4
#define portTIN_SBP_PROGRAM_MEMORY_INTEGRITY_ERROR			5
#define portTIN_SBP_DATA_MEMORY_INTEGRITY_ERROR				6

/* Assertion Trap Identifications. */
#define portTIN_ASSERT_ARITHMETIC_OVERFLOW					1
#define portTIN_ASSERT_STICKY_ARITHMETIC_OVERFLOW			2

/* Non-maskable Interrupt Trap Identifications. */
#define portTIN_NMI_NON_MASKABLE_INTERRUPT					0
/*---------------------------------------------------------------------------*/

void vMMUTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vInternalProtectionTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vInstructionErrorTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vContextManagementTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vSystemBusAndPeripheralsTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vAssertionTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
void vNonMaskableInterruptTrap( int iTrapIdentification ) __attribute__( ( longcall, weak ) );
/*---------------------------------------------------------------------------*/

void vTrapInstallHandlers( void )
{
	if( 0 == _install_trap_handler ( portMMU_TRAP, vMMUTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portIPT_TRAP, vInternalProtectionTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portIE_TRAP, vInstructionErrorTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portCM_TRAP, vContextManagementTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portSBP_TRAP, vSystemBusAndPeripheralsTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portASSERT_TRAP, vAssertionTrap ) )
	{
		_debug();
	}

	if( 0 == _install_trap_handler ( portNMI_TRAP, vNonMaskableInterruptTrap ) )
	{
		_debug();
	}
}
/*-----------------------------------------------------------*/

void vMMUTrap( int iTrapIdentification )
{
	switch( iTrapIdentification )
	{
	case portTIN_MMU_VIRTUAL_ADDRESS_FILL:
	case portTIN_MMU_VIRTUAL_ADDRESS_PROTECTION:
	default:
		_debug();
		break;
	}
}
/*---------------------------------------------------------------------------*/

void vInternalProtectionTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_IPT_PRIVILIGED_INSTRUCTION:
			/* Instruction is not allowed at current execution level, eg DISABLE at User-0. */

		case portTIN_IPT_MEMORY_PROTECTION_READ:
			/* Load word using invalid address. */
			
		case portTIN_IPT_MEMORY_PROTECTION_WRITE:
			/* Store Word using invalid address. */
			
		case portTIN_IPT_MEMORY_PROTECTION_EXECUTION:
			/* PC jumped to an address outside of the valid range. */
			
		case portTIN_IPT_MEMORY_PROTECTION_PERIPHERAL_ACCESS:
			/* Access to a peripheral denied at current execution level. */
			
		case portTIN_IPT_MEMORY_PROTECTION_NULL_ADDRESS:
			/* NULL Pointer. */
			
		case portTIN_IPT_MEMORY_PROTECTION_GLOBAL_REGISTER_WRITE_PROTECTION:
			/* Tried to modify a global address pointer register. */
			
		default:
		
			pxCurrentTCB[ 0 ] = __MFCR( $PCXI );
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/

void vInstructionErrorTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_IE_ILLEGAL_OPCODE:
		case portTIN_IE_UNIMPLEMENTED_OPCODE:
		case portTIN_IE_INVALID_OPERAND:
		case portTIN_IE_DATA_ADDRESS_ALIGNMENT:
		case portTIN_IE_INVALID_LOCAL_MEMORY_ADDRESS:
		default:
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/

void vContextManagementTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_CM_FREE_CONTEXT_LIST_DEPLETION:
		case portTIN_CM_CALL_DEPTH_OVERFLOW:
		case portTIN_CM_CALL_DEPTH_UNDEFLOW:
		case portTIN_CM_FREE_CONTEXT_LIST_UNDERFLOW:
		case portTIN_CM_CALL_STACK_UNDERFLOW:
		case portTIN_CM_CONTEXT_TYPE:
		case portTIN_CM_NESTING_ERROR:
		default:
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/

void vSystemBusAndPeripheralsTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_SBP_PROGRAM_FETCH_SYNCHRONOUS_ERROR:
		case portTIN_SBP_DATA_ACCESS_SYNCHRONOUS_ERROR:
		case portTIN_SBP_DATA_ACCESS_ASYNCHRONOUS_ERROR:
		case portTIN_SBP_COPROCESSOR_TRAP_ASYNCHRONOUS_ERROR:
		case portTIN_SBP_PROGRAM_MEMORY_INTEGRITY_ERROR:
		case portTIN_SBP_DATA_MEMORY_INTEGRITY_ERROR:
		default:
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/

void vAssertionTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_ASSERT_ARITHMETIC_OVERFLOW:
		case portTIN_ASSERT_STICKY_ARITHMETIC_OVERFLOW:
		default:
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/

void vNonMaskableInterruptTrap( int iTrapIdentification )
{
	/* Deliberate fall through to default. */
	switch( iTrapIdentification )
	{
		case portTIN_NMI_NON_MASKABLE_INTERRUPT:
		default:
			_debug();
			break;
	}
}
/*---------------------------------------------------------------------------*/