text: /*
   * FreeRTOS Kernel V10.3.1
   * 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!
   */
  
  #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 */
  
  