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- ;/*
- ; FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd.
- ; All rights reserved
- ;
- ;
- ; ***************************************************************************
- ; * *
- ; * 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 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.
- ;*/
- SYS_MODE EQU 0x1f
- SVC_MODE EQU 0x13
- IRQ_MODE EQU 0x12
- IMPORT ulCriticalNesting
- IMPORT pxCurrentTCB
- IMPORT ulPortTaskHasFPUContext
- IMPORT ulAsmAPIPriorityMask
- IMPORT ulICCPMR
- MACRO
- portSAVE_CONTEXT
- ; Save the LR and SPSR onto the system mode stack before switching to
- ; system mode to save the remaining system mode registers
- SRSDB sp!, #SYS_MODE
- CPS #SYS_MODE
- PUSH {R0-R12, R14}
- ; Push the critical nesting count
- LDR R2, =ulCriticalNesting
- LDR R1, [R2]
- PUSH {R1}
- ; Does the task have a floating point context that needs saving? If
- ; ulPortTaskHasFPUContext is 0 then no.
- LDR R2, =ulPortTaskHasFPUContext
- LDR R3, [R2]
- CMP R3, #0
- ; Save the floating point context, if any
- FMRXNE R1, FPSCR
- VPUSHNE {D0-D15}
- VPUSHNE {D16-D31}
- PUSHNE {R1}
- ; Save ulPortTaskHasFPUContext itself
- PUSH {R3}
- ; Save the stack pointer in the TCB
- LDR R0, =pxCurrentTCB
- LDR R1, [R0]
- STR SP, [R1]
- MEND
- ; /**********************************************************************/
- MACRO
- portRESTORE_CONTEXT
- ; Set the SP to point to the stack of the task being restored.
- LDR R0, =pxCurrentTCB
- LDR R1, [R0]
- LDR SP, [R1]
- ; Is there a floating point context to restore? If the restored
- ; ulPortTaskHasFPUContext is zero then no.
- LDR R0, =ulPortTaskHasFPUContext
- POP {R1}
- STR R1, [R0]
- CMP R1, #0
- ; Restore the floating point context, if any
- POPNE {R0}
- VPOPNE {D16-D31}
- VPOPNE {D0-D15}
- VMSRNE FPSCR, R0
- ; Restore the critical section nesting depth
- LDR R0, =ulCriticalNesting
- POP {R1}
- STR R1, [R0]
- ; Ensure the priority mask is correct for the critical nesting depth
- LDR R2, =ulICCPMR
- CMP R1, #0
- MOVEQ R4, #255
- LDRNE R4, =ulAsmAPIPriorityMask
- STR R4, [r2]
- ; Restore all system mode registers other than the SP (which is already
- ; being used)
- POP {R0-R12, R14}
- ; Return to the task code, loading CPSR on the way.
- RFEIA sp!
- MEND
- END
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