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/*
FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
***************************************************************************
* *
* 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 Richard Barry, 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, training, latest information,
license and contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool.
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.OpenRTOS.com. High Integrity Systems also
provide a safety engineered and independently SIL3 certified version under
the SafeRTOS brand: http://www.SafeRTOS.com.
*/
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 );
#define portSWITCH_CONTEXT() \
asm { mov ax, seg pxCurrentTCB } \
asm { mov ds, ax } \
asm { les bx, pxCurrentTCB } /* Save the stack pointer into the TCB. */ \
asm { mov es:0x2[ bx ], ss } \
asm { mov es:[ bx ], sp } \
asm { call far ptr vTaskSwitchContext } /* Perform the switch. */ \
asm { mov ax, seg pxCurrentTCB } /* Restore the stack pointer from the TCB. */ \
asm { mov ds, ax } \
asm { les bx, dword ptr pxCurrentTCB } \
asm { mov ss, es:[ bx + 2 ] } \
asm { mov sp, es:[ bx ] }
#define portFIRST_CONTEXT() \
asm { mov ax, seg pxCurrentTCB } \
asm { mov ds, ax } \
asm { les bx, dword ptr pxCurrentTCB } \
asm { mov ss, es:[ bx + 2 ] } \
asm { mov sp, es:[ bx ] } \
asm { pop bp } \
asm { pop di } \
asm { pop si } \
asm { pop ds } \
asm { pop es } \
asm { pop dx } \
asm { pop cx } \
asm { pop bx } \
asm { pop ax } \
asm { iret }