text: /*
   * FreeRTOS Kernel V10.4.6
   * 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
   *
   */
  
  typedef void TCB_t;
  extern volatile TCB_t * volatile pxCurrentTCB;
  extern void vTaskSwitchContext( void );
  
  /* 
   * Saves the stack pointer for one task into its TCB, calls 
   * vTaskSwitchContext() to update the TCB being used, then restores the stack 
   * from the new TCB read to run the task. 
   */
  void portSWITCH_CONTEXT( void );
  
  /*
   * Load the stack pointer from the TCB of the task which is going to be first
   * to execute.  Then force an IRET so the registers and IP are popped off the
   * stack.
   */
  void portFIRST_CONTEXT( void );
  
  /* There are slightly different versions depending on whether you are building
  to include debugger information.  If debugger information is used then there
  are a couple of extra bytes left of the ISR stack (presumably for use by the
  debugger).  The true stack pointer is then stored in the bp register.  We add
  2 to the stack pointer to remove the extra bytes before we restore our context. */
  
  #ifdef DEBUG_BUILD
  
  	#pragma aux portSWITCH_CONTEXT =	"mov	ax, seg pxCurrentTCB"														\
  										"mov	ds, ax"																		\
  										"les	bx, pxCurrentTCB"			/* Save the stack pointer into the TCB. */		\
  										"mov	es:0x2[ bx ], ss"															\
  										"mov	es:[ bx ], sp"																\
  										"call	vTaskSwitchContext"			/* Perform the switch. */						\
  										"mov	ax, seg pxCurrentTCB"		/* Restore the stack pointer from the TCB. */	\
  										"mov	ds, ax"																		\
  										"les	bx, dword ptr pxCurrentTCB"													\
  										"mov	ss, es:[ bx + 2 ]"															\
  										"mov	sp, es:[ bx ]"																\
  										"mov	bp, sp"						/* Prepair the bp register for the restoration of the SP in the compiler generated portion of the ISR */	\
  										"add	bp, 0x0002"
  
  										
  
  	#pragma aux portFIRST_CONTEXT =		"mov	ax, seg pxCurrentTCB"			\
  										"mov	ds, ax"							\
  										"les	bx, dword ptr pxCurrentTCB"		\
  										"mov	ss, es:[ bx + 2 ]"				\
  										"mov	sp, es:[ bx ]"					\
  										"add	sp, 0x0002"						/* Remove the extra bytes that exist in debug builds before restoring the context. */ \
  										"pop	ax"								\
  										"pop	ax"								\
  										"pop	es"								\
  										"pop	ds"								\
  										"popa"									\
  										"iret"									
  #else
  
  	#pragma aux portSWITCH_CONTEXT =	"mov	ax, seg pxCurrentTCB"														\
  										"mov	ds, ax"																		\
  										"les	bx, pxCurrentTCB"			/* Save the stack pointer into the TCB. */		\
  										"mov	es:0x2[ bx ], ss"															\
  										"mov	es:[ bx ], sp"																\
  										"call	vTaskSwitchContext"			/* Perform the switch. */						\
  										"mov	ax, seg pxCurrentTCB"		/* Restore the stack pointer from the TCB. */	\
  										"mov	ds, ax"																		\
  										"les	bx, dword ptr pxCurrentTCB"													\
  										"mov	ss, es:[ bx + 2 ]"															\
  										"mov	sp, es:[ bx ]"
  										
  
  	#pragma aux portFIRST_CONTEXT =		"mov	ax, seg pxCurrentTCB"			\
  										"mov	ds, ax"							\
  										"les	bx, dword ptr pxCurrentTCB"		\
  										"mov	ss, es:[ bx + 2 ]"				\
  										"mov	sp, es:[ bx ]"					\
  										"pop	ax"								\
  										"pop	ax"								\
  										"pop	es"								\
  										"pop	ds"								\
  										"popa"									\
  										"iret"									
  #endif
  
  
  