FreeRTOS/Source/portable/oWatcom/16BitDOS/common/portasm.h - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.

     FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT
     http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

     ***************************************************************************
      *                                                                       *
      *    FreeRTOS tutorial books are available in pdf and paperback.        *
      *    Complete, revised, and edited pdf reference manuals are also       *
      *    available.                                                         *
      *                                                                       *
      *    Purchasing FreeRTOS documentation will not only help you, by       *
      *    ensuring you get running as quickly as possible and with an        *
      *    in-depth knowledge of how to use FreeRTOS, it will also help       *
      *    the FreeRTOS project to continue with its mission of providing     *
      *    professional grade, cross platform, de facto standard solutions    *
      *    for microcontrollers - completely free of charge!                  *
      *                                                                       *
      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
      *                                                                       *
      *    Thank you for using FreeRTOS, and thank you for your support!      *
      *                                                                       *
     ***************************************************************************


     This file is part of the FreeRTOS distribution.

     FreeRTOS is free software; you can redistribute it and/or modify it under
     the terms of the GNU General Public License (version 2) as published by the
     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.

     >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
     distribute a combined work that includes FreeRTOS without being obliged to
     provide the source code for proprietary components outside of the FreeRTOS
     kernel.

     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
     details. You should have received a copy of the GNU General Public License
     and the FreeRTOS license exception along with FreeRTOS; if not it can be
     viewed here: http://www.freertos.org/a00114.html and also obtained by
     writing to Real Time Engineers Ltd., contact details for whom are available
     on the FreeRTOS WEB site.

     1 tab == 4 spaces!

     ***************************************************************************
      *                                                                       *
      *    Having a problem?  Start by reading the FAQ "My application does   *
      *    not run, what could be wrong?"                                     *
      *                                                                       *
      *    http://www.FreeRTOS.org/FAQHelp.html                               *
      *                                                                       *
     ***************************************************************************


     http://www.FreeRTOS.org - Documentation, books, training, latest versions,
     license and Real Time Engineers Ltd. contact details.

     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
     including FreeRTOS+Trace - an indispensable productivity tool, and our new
     fully thread aware and reentrant UDP/IP stack.

     http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
     Integrity Systems, who sell the code with commercial support,
     indemnification and middleware, under the OpenRTOS brand.

     http://www.SafeRTOS.com - High Integrity Systems also provide a safety
     engineered and independently SIL3 certified version for use in safety and
     mission critical applications that require provable dependability.
 */

 typedef void tskTCB;
 extern volatile tskTCB * 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
	/*
	FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.

	FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
	http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

	***************************************************************************
	* *
	* FreeRTOS tutorial books are available in pdf and paperback. *
	* Complete, revised, and edited pdf reference manuals are also *
	* available. *
	* *
	* Purchasing FreeRTOS documentation will not only help you, by *
	* ensuring you get running as quickly as possible and with an *
	* in-depth knowledge of how to use FreeRTOS, it will also help *
	* the FreeRTOS project to continue with its mission of providing *
	* professional grade, cross platform, de facto standard solutions *
	* for microcontrollers - completely free of charge! *
	* *
	* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
	* *
	* Thank you for using FreeRTOS, and thank you for your support! *
	* *
	***************************************************************************


	This file is part of the FreeRTOS distribution.

	FreeRTOS is free software; you can redistribute it and/or modify it under
	the terms of the GNU General Public License (version 2) as published by the
	Free Software Foundation AND MODIFIED BY the FreeRTOS exception.

	>>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
	distribute a combined work that includes FreeRTOS without being obliged to
	provide the source code for proprietary components outside of the FreeRTOS
	kernel.

	FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
	details. You should have received a copy of the GNU General Public License
	and the FreeRTOS license exception along with FreeRTOS; if not it can be
	viewed here: http://www.freertos.org/a00114.html and also obtained by
	writing to Real Time Engineers Ltd., contact details for whom are available
	on the FreeRTOS WEB site.

	1 tab == 4 spaces!

	***************************************************************************
	* *
	* Having a problem? Start by reading the FAQ "My application does *
	* not run, what could be wrong?" *
	* *
	* http://www.FreeRTOS.org/FAQHelp.html *
	* *
	***************************************************************************


	http://www.FreeRTOS.org - Documentation, books, training, latest versions,
	license and Real Time Engineers Ltd. contact details.

	http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
	including FreeRTOS+Trace - an indispensable productivity tool, and our new
	fully thread aware and reentrant UDP/IP stack.

	http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
	Integrity Systems, who sell the code with commercial support,
	indemnification and middleware, under the OpenRTOS brand.

	http://www.SafeRTOS.com - High Integrity Systems also provide a safety
	engineered and independently SIL3 certified version for use in safety and
	mission critical applications that require provable dependability.
	*/

	typedef void tskTCB;
	extern volatile tskTCB * 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