;/* | |
; FreeRTOS V7.5.3 - Copyright (C) 2013 Real Time Engineers Ltd. | |
; All rights reserved | |
; | |
; | |
; *************************************************************************** | |
; * * | |
; * FreeRTOS tutorial books are available in pdf and paperback. * | |
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; * available. * | |
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; * professional grade, cross platform, de facto standard solutions * | |
; * for microcontrollers - completely free of charge! * | |
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; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
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; * Thank you for using FreeRTOS, and thank you for your support! * | |
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; *************************************************************************** | |
; | |
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; 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. | |
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; 1 tab == 4 spaces! | |
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; http://www.FreeRTOS.org - Documentation, latest information, license and | |
; contact details. | |
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; http://www.SafeRTOS.com - A version that is certified for use in safety | |
; critical systems. | |
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; http://www.OpenRTOS.com - Commercial support, development, porting, | |
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;*/ | |
EXTERN vTaskSwitchContext | |
EXTERN ulCriticalNesting | |
EXTERN pxCurrentTCB | |
EXTERN ulPortTaskHasFPUContext | |
EXTERN ulAsmAPIPriorityMask | |
portSAVE_CONTEXT macro | |
; 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] | |
endm | |
; /**********************************************************************/ | |
portRESTORE_CONTEXT macro | |
; Switch to system mode | |
CPS #SYS_MODE | |
; 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 | |
LDMFDNE SP!, {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, =portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS | |
CMP R1, #0 | |
MOVEQ R4, #255 | |
LDRNE R4, =( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT ) | |
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! | |
endm | |