/* | |
FreeRTOS V6.1.0 - Copyright (C) 2010 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* If you are: * | |
* * | |
* + New to FreeRTOS, * | |
* + Wanting to learn FreeRTOS or multitasking in general quickly * | |
* + Looking for basic training, * | |
* + Wanting to improve your FreeRTOS skills and productivity * | |
* * | |
* then take a look at the FreeRTOS books - available as PDF or paperback * | |
* * | |
* "Using the FreeRTOS Real Time Kernel - a Practical Guide" * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
* A pdf reference manual is also available. Both are usually delivered * | |
* to your inbox within 20 minutes to two hours when purchased between 8am * | |
* and 8pm GMT (although please allow up to 24 hours in case of * | |
* exceptional circumstances). 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 exception 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! | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
contact details. | |
http://www.SafeRTOS.com - A version that is certified for use in safety | |
critical systems. | |
http://www.OpenRTOS.com - Commercial support, development, porting, | |
licensing and training services. | |
*/ | |
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 } | |