;/* | |
; * FreeRTOS Kernel V10.3.0 | |
; * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
; * | |
; * Permission is hereby granted, free of charge, to any person obtaining a copy of | |
; * this software and associated documentation files (the "Software"), to deal in | |
; * the Software without restriction, including without limitation the rights to | |
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; * the Software, and to permit persons to whom the Software is furnished to do so, | |
; * subject to the following conditions: | |
; * | |
; * The above copyright notice and this permission notice shall be included in all | |
; * copies or substantial portions of the Software. | |
; * | |
; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
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; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR | |
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; * http://www.FreeRTOS.org | |
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; * | |
; * 1 tab == 4 spaces! | |
; */ | |
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} | |
#if configFPU_D32 == 1 | |
VPUSHNE {D16-D31} | |
#endif ; configFPU_D32 | |
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 | |
; 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} | |
#if configFPU_D32 == 1 | |
VPOPNE {D16-D31} | |
#endif ; configFPU_D32 | |
VPOPNE {D0-D15} | |
VMSRNE FPSCR, R0 | |
; Restore the critical section nesting depth | |
LDR R0, =ulCriticalNesting | |
POP {R1} | |
STR R1, [R0] | |
; 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. CPSR has the interrupt | |
; enable bit set appropriately for the task about to execute. | |
RFEIA sp! | |
endm | |