| /* | |
| 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. | |
| */ | |
| /* | |
| Changes from V1.00: | |
| + pxPortInitialiseStack() now initialises the stack of new tasks to the | |
| same format used by the compiler. This allows the compiler generated | |
| interrupt mechanism to be used for context switches. | |
| Changes from V2.4.2: | |
| + pvPortMalloc and vPortFree have been removed. The projects now use | |
| the definitions from the source/portable/MemMang directory. | |
| Changes from V2.6.1: | |
| + usPortCheckFreeStackSpace() has been moved to tasks.c. | |
| */ | |
| #include <stdlib.h> | |
| #include "FreeRTOS.h" | |
| /*-----------------------------------------------------------*/ | |
| /* See header file for description. */ | |
| portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters ) | |
| { | |
| portSTACK_TYPE DS_Reg = 0, *pxOriginalSP; | |
| /* Place a few bytes of known values on the bottom of the stack. | |
| This is just useful for debugging. */ | |
| *pxTopOfStack = 0x1111; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x2222; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x3333; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x4444; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x5555; | |
| pxTopOfStack--; | |
| /*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */ | |
| /* We are going to start the scheduler using a return from interrupt | |
| instruction to load the program counter, so first there would be the | |
| status register and interrupt return address. We make this the start | |
| of the task. */ | |
| *pxTopOfStack = portINITIAL_SW; | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_SEG( pxCode ); | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_OFF( pxCode ); | |
| pxTopOfStack--; | |
| /* We are going to setup the stack for the new task to look like | |
| the stack frame was setup by a compiler generated ISR. We need to know | |
| the address of the existing stack top to place in the SP register within | |
| the stack frame. pxOriginalSP holds SP before (simulated) pusha was | |
| called. */ | |
| pxOriginalSP = pxTopOfStack; | |
| /* The remaining registers would be pushed on the stack by our context | |
| switch function. These are loaded with values simply to make debugging | |
| easier. */ | |
| *pxTopOfStack = FP_OFF( pvParameters ); /* AX */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0xCCCC; /* CX */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_SEG( pvParameters ); /* DX */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0xBBBB; /* BX */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_OFF( pxOriginalSP ); /* SP */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0xBBBB; /* BP */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0x0123; /* SI */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0xDDDD; /* DI */ | |
| /* We need the true data segment. */ | |
| __asm{ MOV DS_Reg, DS }; | |
| pxTopOfStack--; | |
| *pxTopOfStack = DS_Reg; /* DS */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( portSTACK_TYPE ) 0xEEEE; /* ES */ | |
| /* The AX register is pushed again twice - don't know why. */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_OFF( pvParameters ); /* AX */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = FP_OFF( pvParameters ); /* AX */ | |
| #ifdef DEBUG_BUILD | |
| /* The compiler adds space to each ISR stack if building to | |
| include debug information. Presumably this is used by the | |
| debugger - we don't need to initialise it to anything just | |
| make sure it is there. */ | |
| pxTopOfStack--; | |
| #endif | |
| /*lint +e950 +e611 +e923 */ | |
| return pxTopOfStack; | |
| } | |
| /*-----------------------------------------------------------*/ | |