/*
 * FreeRTOS Kernel <DEVELOPMENT BRANCH>
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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
 *
 */

#ifndef PORTMACRO_H
#define PORTMACRO_H

#ifdef __cplusplus
extern "C" {
#endif

/*-----------------------------------------------------------
 * Port specific definitions.
 *
 * The settings in this file configure FreeRTOS correctly for the
 * given hardware and compiler.
 *
 * These settings should not be altered.
 *-----------------------------------------------------------
 */

/* Type definitions. */
#define portCHAR		char
#define portFLOAT		float
#define portDOUBLE		double
#define portLONG		long
#define portSHORT		short
#define portSTACK_TYPE	uint32_t
#define portBASE_TYPE	portLONG

typedef portSTACK_TYPE StackType_t;
typedef long BaseType_t;
typedef unsigned long UBaseType_t;

#if( configUSE_16_BIT_TICKS == 1 )
	typedef uint16_t TickType_t;
	#define portMAX_DELAY ( TickType_t ) 0xffff
#else
	typedef uint32_t TickType_t;
	#define portMAX_DELAY ( TickType_t ) 0xffffffffUL
#endif
/*-----------------------------------------------------------*/

/* Architecture specifics. */
#define portSTACK_GROWTH			( -1 )
#define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
#define portBYTE_ALIGNMENT			8
#define portNOP()					__asm volatile ( "NOP" );
/*-----------------------------------------------------------*/


/* Scheduler utilities. */

/*
 * portRESTORE_CONTEXT, portRESTORE_CONTEXT, portENTER_SWITCHING_ISR
 * and portEXIT_SWITCHING_ISR can only be called from ARM mode, but
 * are included here for efficiency.  An attempt to call one from
 * THUMB mode code will result in a compile time error.
 */

#define portRESTORE_CONTEXT()											\
{																		\
extern volatile void * volatile pxCurrentTCB;							\
extern volatile uint32_t ulCriticalNesting;					\
																		\
	/* Set the LR to the task stack. */									\
	__asm volatile (													\
	"LDR		R0, =pxCurrentTCB								\n\t"	\
	"LDR		R0, [R0]										\n\t"	\
	"LDR		LR, [R0]										\n\t"	\
																		\
	/* The critical nesting depth is the first item on the stack. */	\
	/* Load it into the ulCriticalNesting variable. */					\
	"LDR		R0, =ulCriticalNesting							\n\t"	\
	"LDMFD	LR!, {R1}											\n\t"	\
	"STR		R1, [R0]										\n\t"	\
																		\
	/* Get the SPSR from the stack. */									\
	"LDMFD	LR!, {R0}											\n\t"	\
	"MSR		SPSR, R0										\n\t"	\
																		\
	/* Restore all system mode registers for the task. */				\
	"LDMFD	LR, {R0-R14}^										\n\t"	\
	"NOP														\n\t"	\
																		\
	/* Restore the return address. */									\
	"LDR		LR, [LR, #+60]									\n\t"	\
																		\
	/* And return - correcting the offset in the LR to obtain the */	\
	/* correct address. */												\
	"SUBS	PC, LR, #4											\n\t"	\
	);																	\
	( void ) ulCriticalNesting;											\
	( void ) pxCurrentTCB;												\
}
/*-----------------------------------------------------------*/

#define portSAVE_CONTEXT()												\
{																		\
extern volatile void * volatile pxCurrentTCB;							\
extern volatile uint32_t ulCriticalNesting;					\
																		\
	/* Push R0 as we are going to use the register. */					\
	__asm volatile (													\
	"STMDB	SP!, {R0}											\n\t"	\
																		\
	/* Set R0 to point to the task stack pointer. */					\
	"STMDB	SP,{SP}^											\n\t"	\
	"NOP														\n\t"	\
	"SUB	SP, SP, #4											\n\t"	\
	"LDMIA	SP!,{R0}											\n\t"	\
																		\
	/* Push the return address onto the stack. */						\
	"STMDB	R0!, {LR}											\n\t"	\
																		\
	/* Now we have saved LR we can use it instead of R0. */				\
	"MOV	LR, R0												\n\t"	\
																		\
	/* Pop R0 so we can save it onto the system mode stack. */			\
	"LDMIA	SP!, {R0}											\n\t"	\
																		\
	/* Push all the system mode registers onto the task stack. */		\
	"STMDB	LR,{R0-LR}^											\n\t"	\
	"NOP														\n\t"	\
	"SUB	LR, LR, #60											\n\t"	\
																		\
	/* Push the SPSR onto the task stack. */							\
	"MRS	R0, SPSR											\n\t"	\
	"STMDB	LR!, {R0}											\n\t"	\
																		\
	"LDR	R0, =ulCriticalNesting								\n\t"	\
	"LDR	R0, [R0]											\n\t"	\
	"STMDB	LR!, {R0}											\n\t"	\
																		\
	/* Store the new top of stack for the task. */						\
	"LDR	R0, =pxCurrentTCB									\n\t"	\
	"LDR	R0, [R0]											\n\t"	\
	"STR	LR, [R0]											\n\t"	\
	);																	\
	( void ) ulCriticalNesting;											\
	( void ) pxCurrentTCB;												\
}

extern void vTaskSwitchContext( void );
#define portYIELD_FROM_ISR()		vTaskSwitchContext()
#define portYIELD()					__asm volatile ( "SWI 0" )
/*-----------------------------------------------------------*/


/* Critical section management. */

/*
 * The interrupt management utilities can only be called from ARM mode.  When
 * THUMB_INTERWORK is defined the utilities are defined as functions in
 * portISR.c to ensure a switch to ARM mode.  When THUMB_INTERWORK is not
 * defined then the utilities are defined as macros here - as per other ports.
 */

#ifdef THUMB_INTERWORK

	extern void vPortDisableInterruptsFromThumb( void ) __attribute__ ((naked));
	extern void vPortEnableInterruptsFromThumb( void ) __attribute__ ((naked));

	#define portDISABLE_INTERRUPTS()	vPortDisableInterruptsFromThumb()
	#define portENABLE_INTERRUPTS()		vPortEnableInterruptsFromThumb()

#else

	#define portDISABLE_INTERRUPTS()											\
		__asm volatile (														\
			"STMDB	SP!, {R0}		\n\t"	/* Push R0.						*/	\
			"MRS	R0, CPSR		\n\t"	/* Get CPSR.					*/	\
			"ORR	R0, R0, #0xC0	\n\t"	/* Disable IRQ, FIQ.			*/	\
			"MSR	CPSR, R0		\n\t"	/* Write back modified value.	*/	\
			"LDMIA	SP!, {R0}			" )	/* Pop R0.						*/

	#define portENABLE_INTERRUPTS()												\
		__asm volatile (														\
			"STMDB	SP!, {R0}		\n\t"	/* Push R0.						*/	\
			"MRS	R0, CPSR		\n\t"	/* Get CPSR.					*/	\
			"BIC	R0, R0, #0xC0	\n\t"	/* Enable IRQ, FIQ.				*/	\
			"MSR	CPSR, R0		\n\t"	/* Write back modified value.	*/	\
			"LDMIA	SP!, {R0}			" )	/* Pop R0.						*/

#endif /* THUMB_INTERWORK */

extern void vPortEnterCritical( void );
extern void vPortExitCritical( void );

#define portENTER_CRITICAL()		vPortEnterCritical();
#define portEXIT_CRITICAL()			vPortExitCritical();
/*-----------------------------------------------------------*/

/* Task function macros as described on the FreeRTOS.org WEB site. */
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )

#ifdef __cplusplus
}
#endif

#endif /* PORTMACRO_H */

