| ;/* | |
| ; * FreeRTOS Kernel <DEVELOPMENT BRANCH> | |
| ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
| ; * | |
| ; * SPDX-License-Identifier: MIT | |
| ; * | |
| ; * 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 | |
| ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of | |
| ; * 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 | |
| ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS | |
| ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR | |
| ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER | |
| ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
| ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
| ; * | |
| ; * https://www.FreeRTOS.org | |
| ; * https://github.com/FreeRTOS | |
| ; * | |
| ; */ | |
| 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 | |