mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
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143 lines
5.2 KiB
C
143 lines
5.2 KiB
C
/*
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FreeRTOS V7.5.2 - Copyright (C) 2013 Real Time Engineers Ltd.
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VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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***************************************************************************
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* *
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* FreeRTOS provides completely free yet professionally developed, *
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* robust, strictly quality controlled, supported, and cross *
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* platform software that has become a de facto standard. *
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* *
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* Help yourself get started quickly and support the FreeRTOS *
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* project by purchasing a FreeRTOS tutorial book, reference *
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* manual, or both from: http://www.FreeRTOS.org/Documentation *
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* *
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* Thank you! *
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* *
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***************************************************************************
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This file is part of the FreeRTOS distribution.
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FreeRTOS is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License (version 2) as published by the
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Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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>>! NOTE: The modification to the GPL is included to allow you to distribute
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>>! a combined work that includes FreeRTOS without being obliged to provide
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>>! the source code for proprietary components outside of the FreeRTOS
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>>! kernel.
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FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. Full license text is available from the following
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link: http://www.freertos.org/a00114.html
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1 tab == 4 spaces!
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***************************************************************************
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* *
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* Having a problem? Start by reading the FAQ "My application does *
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* not run, what could be wrong?" *
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* *
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* http://www.FreeRTOS.org/FAQHelp.html *
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* *
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***************************************************************************
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http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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license and Real Time Engineers Ltd. contact details.
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http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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compatible FAT file system, and our tiny thread aware UDP/IP stack.
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http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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licenses offer ticketed support, indemnification and middleware.
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http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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engineered and independently SIL3 certified version for use in safety and
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mission critical applications that require provable dependability.
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1 tab == 4 spaces!
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*/
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EXTERN pxCurrentTCB
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EXTERN ulCriticalNesting
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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; Context save and restore macro definitions
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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portSAVE_CONTEXT MACRO
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; Push R0 as we are going to use the register.
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STMDB SP!, {R0}
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; Set R0 to point to the task stack pointer.
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STMDB SP, {SP}^
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NOP
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SUB SP, SP, #4
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LDMIA SP!, {R0}
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; Push the return address onto the stack.
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STMDB R0!, {LR}
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; Now we have saved LR we can use it instead of R0.
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MOV LR, R0
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; Pop R0 so we can save it onto the system mode stack.
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LDMIA SP!, {R0}
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; Push all the system mode registers onto the task stack.
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STMDB LR, {R0-LR}^
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NOP
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SUB LR, LR, #60
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; Push the SPSR onto the task stack.
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MRS R0, SPSR
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STMDB LR!, {R0}
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LDR R0, =ulCriticalNesting
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LDR R0, [R0]
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STMDB LR!, {R0}
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; Store the new top of stack for the task.
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LDR R1, =pxCurrentTCB
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LDR R0, [R1]
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STR LR, [R0]
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ENDM
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portRESTORE_CONTEXT MACRO
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; Set the LR to the task stack.
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LDR R1, =pxCurrentTCB
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LDR R0, [R1]
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LDR LR, [R0]
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; The critical nesting depth is the first item on the stack.
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; Load it into the ulCriticalNesting variable.
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LDR R0, =ulCriticalNesting
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LDMFD LR!, {R1}
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STR R1, [R0]
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; Get the SPSR from the stack.
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LDMFD LR!, {R0}
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MSR SPSR_cxsf, R0
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; Restore all system mode registers for the task.
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LDMFD LR, {R0-R14}^
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NOP
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; Restore the return address.
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LDR LR, [LR, #+60]
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; And return - correcting the offset in the LR to obtain the
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; correct address.
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SUBS PC, LR, #4
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ENDM
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