| ;/*
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| ; * FreeRTOS Kernel <DEVELOPMENT BRANCH>
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| ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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| ; *
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| ; * SPDX-License-Identifier: MIT |
| ; * |
| ; * Permission is hereby granted, free of charge, to any person obtaining a copy of
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| ; * this software and associated documentation files (the "Software"), to deal in
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| ; * the Software without restriction, including without limitation the rights to
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| ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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| ; * the Software, and to permit persons to whom the Software is furnished to do so,
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| ; * subject to the following conditions:
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| ; *
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| ; * The above copyright notice and this permission notice shall be included in all
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| ; * copies or substantial portions of the Software.
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| ; *
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| ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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| ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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| ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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| ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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| ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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| ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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| ; *
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| ; * https://www.FreeRTOS.org
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| ; * https://github.com/FreeRTOS
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| ; *
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| ; */
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| SYS_MODE EQU 0x1f
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| SVC_MODE EQU 0x13
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| IRQ_MODE EQU 0x12
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| IMPORT ulCriticalNesting
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| IMPORT pxCurrentTCB
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| IMPORT ulPortTaskHasFPUContext
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| IMPORT ulAsmAPIPriorityMask
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| IMPORT ulICCPMR
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| MACRO
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| portSAVE_CONTEXT
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| ; Save the LR and SPSR onto the system mode stack before switching to
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| ; system mode to save the remaining system mode registers
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| SRSDB sp!, #SYS_MODE
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| CPS #SYS_MODE
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| PUSH {R0-R12, R14}
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| ; Push the critical nesting count
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| LDR R2, =ulCriticalNesting
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| LDR R1, [R2]
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| PUSH {R1}
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| ; Does the task have a floating point context that needs saving? If
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| ; ulPortTaskHasFPUContext is 0 then no.
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| LDR R2, =ulPortTaskHasFPUContext
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| LDR R3, [R2]
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| CMP R3, #0
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| ; Save the floating point context, if any
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| FMRXNE R1, FPSCR
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| VPUSHNE {D0-D15}
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| VPUSHNE {D16-D31}
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| PUSHNE {R1}
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| ; Save ulPortTaskHasFPUContext itself
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| PUSH {R3}
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| ; Save the stack pointer in the TCB
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| LDR R0, =pxCurrentTCB
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| LDR R1, [R0]
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| STR SP, [R1]
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|
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| MEND
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| ; /**********************************************************************/
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|
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| MACRO
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| portRESTORE_CONTEXT
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| ; Set the SP to point to the stack of the task being restored.
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| LDR R0, =pxCurrentTCB
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| LDR R1, [R0]
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| LDR SP, [R1]
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| ; Is there a floating point context to restore? If the restored
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| ; ulPortTaskHasFPUContext is zero then no.
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| LDR R0, =ulPortTaskHasFPUContext
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| POP {R1}
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| STR R1, [R0]
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| CMP R1, #0
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| ; Restore the floating point context, if any
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| POPNE {R0}
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| VPOPNE {D16-D31}
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| VPOPNE {D0-D15}
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| VMSRNE FPSCR, R0
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| ; Restore the critical section nesting depth
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| LDR R0, =ulCriticalNesting
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| POP {R1}
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| STR R1, [R0]
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| ; Ensure the priority mask is correct for the critical nesting depth
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| LDR R2, =ulICCPMR
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| CMP R1, #0
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| MOVEQ R4, #255
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| LDRNE R4, =ulAsmAPIPriorityMask
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| STR R4, [r2]
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| ; Restore all system mode registers other than the SP (which is already
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| ; being used)
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| POP {R0-R12, R14}
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| ; Return to the task code, loading CPSR on the way.
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| RFEIA sp!
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| MEND
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| END
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