/* | |
FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd. | |
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. | |
Alternative commercial license and support terms are also available upon | |
request. See the licensing section of http://www.FreeRTOS.org for full | |
license details. | |
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 along | |
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59 | |
Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
*************************************************************************** | |
* * | |
* Looking for a quick start? Then check out the FreeRTOS eBook! * | |
* See http://www.FreeRTOS.org/Documentation for details * | |
* * | |
*************************************************************************** | |
1 tab == 4 spaces! | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
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. | |
*/ | |
#ifndef PORT_ASM_H | |
#define PORT_ASM_H | |
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. */ | |
#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 } | |
#endif | |