2 FreeRTOS V7.5.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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6 ***************************************************************************
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8 * FreeRTOS provides completely free yet professionally developed, *
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9 * robust, strictly quality controlled, supported, and cross *
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10 * platform software that has become a de facto standard. *
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12 * Help yourself get started quickly and support the FreeRTOS *
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13 * project by purchasing a FreeRTOS tutorial book, reference *
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14 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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18 ***************************************************************************
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20 This file is part of the FreeRTOS distribution.
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22 FreeRTOS is free software; you can redistribute it and/or modify it under
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23 the terms of the GNU General Public License (version 2) as published by the
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24 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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26 >>! NOTE: The modification to the GPL is included to allow you to distribute
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27 >>! a combined work that includes FreeRTOS without being obliged to provide
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28 >>! the source code for proprietary components outside of the FreeRTOS
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31 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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32 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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33 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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34 link: http://www.freertos.org/a00114.html
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38 ***************************************************************************
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40 * Having a problem? Start by reading the FAQ "My application does *
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41 * not run, what could be wrong?" *
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43 * http://www.FreeRTOS.org/FAQHelp.html *
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45 ***************************************************************************
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47 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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48 license and Real Time Engineers Ltd. contact details.
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50 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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51 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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52 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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54 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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55 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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56 licenses offer ticketed support, indemnification and middleware.
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58 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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59 engineered and independently SIL3 certified version for use in safety and
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60 mission critical applications that require provable dependability.
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68 typedef void tskTCB;
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69 extern volatile tskTCB * volatile pxCurrentTCB;
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70 extern void vTaskSwitchContext( void );
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73 * Saves the stack pointer for one task into its TCB, calls
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74 * vTaskSwitchContext() to update the TCB being used, then restores the stack
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75 * from the new TCB read to run the task.
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77 void portSWITCH_CONTEXT( void );
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80 * Load the stack pointer from the TCB of the task which is going to be first
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81 * to execute. Then force an IRET so the registers and IP are popped off the
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84 void portFIRST_CONTEXT( void );
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86 /* There are slightly different versions depending on whether you are building
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87 to include debugger information. If debugger information is used then there
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88 are a couple of extra bytes left of the ISR stack (presumably for use by the
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89 debugger). The true stack pointer is then stored in the bp register. We add
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90 2 to the stack pointer to remove the extra bytes before we restore our context. */
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92 #define portSWITCH_CONTEXT() \
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93 asm { mov ax, seg pxCurrentTCB } \
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94 asm { mov ds, ax } \
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95 asm { les bx, pxCurrentTCB } /* Save the stack pointer into the TCB. */ \
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96 asm { mov es:0x2[ bx ], ss } \
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97 asm { mov es:[ bx ], sp } \
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98 asm { call far ptr vTaskSwitchContext } /* Perform the switch. */ \
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99 asm { mov ax, seg pxCurrentTCB } /* Restore the stack pointer from the TCB. */ \
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100 asm { mov ds, ax } \
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101 asm { les bx, dword ptr pxCurrentTCB } \
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102 asm { mov ss, es:[ bx + 2 ] } \
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103 asm { mov sp, es:[ bx ] }
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105 #define portFIRST_CONTEXT() \
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106 __asm { mov ax, seg pxCurrentTCB } \
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107 __asm { mov ds, ax } \
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108 __asm { les bx, dword ptr pxCurrentTCB } \
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109 __asm { mov ss, es:[ bx + 2 ] } \
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110 __asm { mov sp, es:[ bx ] } \
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