| ;/* |
| ; * 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 |