/*
 * FreeRTOS Kernel V10.3.0
 * 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!
 */

/*
 * "Reg test" tasks - These fill the registers with known values, then check
 * that each register maintains its expected value for the lifetime of the
 * task.  Each task uses a different set of values.  The reg test tasks execute
 * with a very low priority, so get preempted very frequently.  A register
 * containing an unexpected value is indicative of an error in the context
 * switching mechanism.
 */

void vRegTest1Implementation( void ) __attribute__ ((naked));
void vRegTest2Implementation( void ) __attribute__ ((naked));

void vRegTest1Implementation( void )
{
	__asm volatile
	(
		".extern ulRegTest1LoopCounter \n"
		"/* Fill the core registers with known values. */		\n"
		"mov	r0, #100			\n"
		"mov	r1, #101			\n"
		"mov	r2, #102			\n"
		"mov	r3, #103			\n"
		"mov	r4, #104			\n"
		"mov	r5, #105			\n"
		"mov	r6, #106			\n"
		"mov	r7, #107			\n"
		"mov	r8, #108			\n"
		"mov	r9, #109			\n"
		"mov	r10, #110			\n"
		"mov	r11, #111			\n"
		"mov	r12, #112			\n"

	"reg1_loop:						\n"

		"/* Check each register has maintained its expected value. */	\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"
		"cmp	r8, #108			\n"
		"bne	reg1_error_loop		\n"
		"cmp	r9, #109			\n"
		"bne	reg1_error_loop		\n"
		"cmp	r10, #110			\n"
		"bne	reg1_error_loop		\n"
		"cmp	r11, #111			\n"
		"bne	reg1_error_loop		\n"
		"cmp	r12, #112			\n"
		"bne	reg1_error_loop		\n"

		"/* Everything passed, increment the loop counter. */	\n"
		"push 	{ r0-r1 }			\n"
		"ldr	r0, =ulRegTest1LoopCounter	\n"
		"ldr 	r1, [r0]			\n"
		"adds 	r1, r1, #1			\n"
		"str 	r1, [r0]			\n"
		"pop 	{ r0-r1 }			\n"

		"/* Start again. */			\n"
		"b 		reg1_loop			\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						"
	); /* __asm volatile. */
}
/*-----------------------------------------------------------*/

void vRegTest2Implementation( void )
{
	__asm volatile
	(
		".extern ulRegTest2LoopCounter \n"
		"/* Set all the core registers to known values. */	\n"
		"mov 	r0, #-1				\n"
		"mov 	r1, #1				\n"
		"mov 	r2, #2				\n"
		"mov 	r3, #3				\n"
		"mov	r4, #4				\n"
		"mov	r5, #5				\n"
		"mov	r6, #6				\n"
		"mov 	r7, #7				\n"
		"mov	r8, #8				\n"
		"mov	r9, #9				\n"
		"mov	r10, #10			\n"
		"mov	r11, #11			\n"
		"mov 	r12, #12			\n"

	"reg2_loop:						\n"

		"cmp	r0, #-1				\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"
		"cmp	r8, #8				\n"
		"bne	reg2_error_loop		\n"
		"cmp	r9, #9				\n"
		"bne	reg2_error_loop		\n"
		"cmp	r10, #10			\n"
		"bne	reg2_error_loop		\n"
		"cmp	r11, #11			\n"
		"bne	reg2_error_loop		\n"
		"cmp	r12, #12			\n"
		"bne	reg2_error_loop		\n"

		"/* Increment the loop counter to indicate this test is still functioning	\n"
		"correctly. */				\n"
		"push	{ r0-r1 }			\n"
		"ldr	r0, =ulRegTest2LoopCounter	\n"
		"ldr 	r1, [r0]			\n"
		"adds 	r1, r1, #1			\n"
		"str 	r1, [r0]			\n"

		"/* Yield to increase test coverage. */			\n"
		"movs 	r0, #0x01			\n"
		"ldr 	r1, =0xe000ed04 /*NVIC_INT_CTRL */		\n"
		"lsl 	r0, r0, #28 /* Shift to PendSV bit */	\n"
		"str 	r0, [r1]			\n"
		"dsb						\n"

		"pop { r0-r1 }				\n"

		"/* Start again. */			\n"
		"b reg2_loop				\n"

	"reg2_error_loop:				\n"
		"/* If this line is hit then there was an error in a core register value.	\n"
		"This loop ensures the loop counter variable stops incrementing. */			\n"
		"b reg2_error_loop			\n"
	); /* __asm volatile */
}
/*-----------------------------------------------------------*/