/*
 * FreeRTOS V202111.00
 * 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.
 *
 * http://www.FreeRTOS.org
 * http://aws.amazon.com/freertos
 *
 * 1 tab == 4 spaces!
 */

/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"

/* Interface include files. */
#include "RegTests.h"

/* Tasks that implement register tests. */
static void prvRegisterTest1Task( void *pvParameters );
static void prvRegisterTest2Task( void *pvParameters );
static void prvRegisterTest3Task( void *pvParameters );
static void prvRegisterTest4Task( void *pvParameters );

/* Flag that will be latched to pdTRUE should any unexpected behaviour be
detected in any of the tasks. */
static volatile BaseType_t xErrorDetected = pdFALSE;

/* Counters that are incremented on each cycle of a test.  This is used to
detect a stalled task - a test that is no longer running. */
static volatile uint32_t ulRegisterTest1Counter = 0;
static volatile uint32_t ulRegisterTest2Counter = 0;
static volatile uint32_t ulRegisterTest3Counter = 0;
static volatile uint32_t ulRegisterTest4Counter = 0;
/*-----------------------------------------------------------*/

static void prvRegisterTest1Task( void *pvParameters )
{
	( void ) pvParameters;

	for( ; ; )
	{
		__asm volatile
		(
			".extern ulRegisterTest1Counter		\n"
			"									\n"
			"	/* Fill the core registers with known values. */ \n"
			"	movs r1, #101					\n"
			"	movs r2, #102					\n"
			"	movs r3, #103					\n"
			"	movs r4, #104					\n"
			"	movs r5, #105					\n"
			"	movs r6, #106					\n"
			"	movs r7, #107					\n"
			"	movs r0, #108					\n"
			"	mov	 r8, r0						\n"
			"	movs r0, #109					\n"
			"	mov  r9, r0						\n"
			"	movs r0, #110					\n"
			"	mov	 r10, r0					\n"
			"	movs r0, #111					\n"
			"	mov	 r11, r0					\n"
			"	movs r0, #112					\n"
			"	mov  r12, r0					\n"
			"	movs r0, #100					\n"
			"									\n"
			"reg1_loop:							\n"
			"									\n"
			"	cmp	r0, #100					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r1, #101					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r2, #102					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp r3, #103					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r4, #104					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r5, #105					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r6, #106					\n"
			"	bne	reg1_error_loop				\n"
			"	cmp	r7, #107					\n"
			"	bne	reg1_error_loop				\n"
			"	movs r0, #108					\n"
			"	cmp	r8, r0						\n"
			"	bne	reg1_error_loop				\n"
			"	movs r0, #109					\n"
			"	cmp	r9, r0						\n"
			"	bne	reg1_error_loop				\n"
			"	movs r0, #110					\n"
			"	cmp	r10, r0						\n"
			"	bne	reg1_error_loop				\n"
			"	movs r0, #111					\n"
			"	cmp	r11, r0						\n"
			"	bne	reg1_error_loop				\n"
			"	movs r0, #112					\n"
			"	cmp	r12, r0						\n"
			"	bne	reg1_error_loop				\n"
			"									\n"
			"	/* Everything passed, increment the loop counter. */ \n"
			"	push { r1 }						\n"
			"	ldr	r0, =ulRegisterTest1Counter	\n"
			"	ldr r1, [r0]					\n"
			"	adds r1, r1, #1					\n"
			"	str r1, [r0]					\n"
			"	pop { r1 }						\n"
			"									\n"
			"	/* Start again. */				\n"
			"	movs r0, #100					\n"
			"	b reg1_loop						\n"
			"									\n"
			"reg1_error_loop:					\n"
			"	/* If this line is hit then there was an error in a core register value. 	\n"
			"	The loop ensures the loop counter stops incrementing. */					\n"
			"	b reg1_error_loop				\n"
			"	nop								\n"
		);
	}
}
/*-----------------------------------------------------------*/

static void prvRegisterTest2Task( void *pvParameters )
{
	( void ) pvParameters;

	for( ; ; )
	{
		__asm volatile
		(
			".extern ulRegisterTest2Counter		\n"
			"									\n"
			"	/* Fill the core registers with known values. */ \n"
			"	movs r1, #1						\n"
			"	movs r2, #2						\n"
			"	movs r3, #3						\n"
			"	movs r4, #4						\n"
			"	movs r5, #5						\n"
			"	movs r6, #6						\n"
			"	movs r7, #7						\n"
			"	movs r0, #8						\n"
			"	mov r8, r0						\n"
			"	movs r0, #9						\n"
			"	mov  r9, r0						\n"
			"	movs r0, #10					\n"
			"	mov	 r10, r0					\n"
			"	movs r0, #11					\n"
			"	mov	 r11, r0					\n"
			"	movs r0, #12					\n"
			"	mov  r12, r0					\n"
			"	movs r0, #10					\n"
			"									\n"
			"reg2_loop:							\n"
			"									\n"
			"	cmp	r0, #10						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r1, #1						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r2, #2						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp r3, #3						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r4, #4						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r5, #5						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r6, #6						\n"
			"	bne	reg2_error_loop				\n"
			"	cmp	r7, #7						\n"
			"	bne	reg2_error_loop				\n"
			"	movs r0, #8						\n"
			"	cmp	r8, r0						\n"
			"	bne	reg2_error_loop				\n"
			"	movs r0, #9						\n"
			"	cmp	r9, r0						\n"
			"	bne	reg2_error_loop				\n"
			"	movs r0, #10					\n"
			"	cmp	r10, r0						\n"
			"	bne	reg2_error_loop				\n"
			"	movs r0, #11					\n"
			"	cmp	r11, r0						\n"
			"	bne	reg2_error_loop				\n"
			"	movs r0, #12					\n"
			"	cmp	r12, r0						\n"
			"	bne	reg2_error_loop				\n"
			"									\n"
			"	/* Everything passed, increment the loop counter. */ \n"
			"	push { r1 }						\n"
			"	ldr	r0, =ulRegisterTest2Counter	\n"
			"	ldr r1, [r0]					\n"
			"	adds r1, r1, #1					\n"
			"	str r1, [r0]					\n"
			"	pop { r1 }						\n"
			"									\n"
			"	/* Start again. */				\n"
			"	movs r0, #10					\n"
			"	b reg2_loop						\n"
			"									\n"
			"reg2_error_loop:					\n"
			"	/* If this line is hit then there was an error in a core register value. 	\n"
			"	The loop ensures the loop counter stops incrementing. */					\n"
			"	b reg2_error_loop				\n"
			"	nop								\n"
		);
	}
}
/*-----------------------------------------------------------*/

static void prvRegisterTest3Task( void *pvParameters )
{
	( void ) pvParameters;

	for( ; ; )
	{
		/* 1. Fill the registers stored as part of task context with known values.
		* 2. Force a context switch.
		* 3. Verify that all the registers contain expected values.
		* 4. If all the register contain expected values, increment ulRegisterTest3Counter.
		*/
		ulRegisterTest3Counter++;
	}
}
/*-----------------------------------------------------------*/

static void prvRegisterTest4Task( void *pvParameters )
{
	( void ) pvParameters;

	for( ; ; )
	{
		/* 1. Fill the registers stored as part of task context with known values.
		* 2. Force a context switch.
		* 3. Verify that all the registers contain expected values.
		* 4. If all the register contain expected values, increment ulRegisterTest4Counter.
		*/
		ulRegisterTest4Counter++;
	}
}
/*-----------------------------------------------------------*/

void vStartRegisterTasks( UBaseType_t uxPriority )
{
	BaseType_t ret;

	ret = xTaskCreate( prvRegisterTest1Task, "RegTest1", configMINIMAL_STACK_SIZE, NULL, uxPriority, NULL );
	configASSERT( ret == pdPASS );

	ret = xTaskCreate( prvRegisterTest2Task, "RegTest2", configMINIMAL_STACK_SIZE, NULL, uxPriority, NULL );
	configASSERT( ret == pdPASS );

	ret = xTaskCreate( prvRegisterTest3Task, "RegTest3", configMINIMAL_STACK_SIZE, NULL, uxPriority, NULL );
	configASSERT( ret == pdPASS );

	ret = xTaskCreate( prvRegisterTest4Task, "RegTest4", configMINIMAL_STACK_SIZE, NULL, uxPriority, NULL );
	configASSERT( ret == pdPASS );
}
/*-----------------------------------------------------------*/

BaseType_t xAreRegisterTasksStillRunning( void )
{
	static uint32_t ulLastRegisterTest1Counter = 0, ulLastRegisterTest2Counter = 0;
	static uint32_t ulLastRegisterTest3Counter = 0, ulLastRegisterTest4Counter = 0;

	/* If the register test task is still running then we expect the loop
	 * counters to have incremented since this function was last called. */
	if( ulLastRegisterTest1Counter == ulRegisterTest1Counter )
	{
		xErrorDetected = pdTRUE;
	}

	if( ulLastRegisterTest2Counter == ulRegisterTest2Counter )
	{
		xErrorDetected = pdTRUE;
	}

	if( ulLastRegisterTest3Counter == ulRegisterTest3Counter )
	{
		xErrorDetected = pdTRUE;
	}

	if( ulLastRegisterTest4Counter == ulRegisterTest4Counter )
	{
		xErrorDetected = pdTRUE;
	}

	ulLastRegisterTest1Counter = ulRegisterTest1Counter;
	ulLastRegisterTest2Counter = ulRegisterTest2Counter;
	ulLastRegisterTest3Counter = ulRegisterTest3Counter;
	ulLastRegisterTest4Counter = ulRegisterTest4Counter;

	/* Errors detected in the task itself will have latched xErrorDetected
	 * to true. */
	return ( BaseType_t ) !xErrorDetected;
}
/*-----------------------------------------------------------*/