;/* ; * FreeRTOS Kernel V10.0.0 ; * Copyright (C) 2017 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 ; * 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. If you wish to use our Amazon ; * FreeRTOS name, please do so in a fair use way that does not cause confusion. ; * ; * 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. ; * ; * http://www.FreeRTOS.org ; * http://aws.amazon.com/freertos ; * ; * 1 tab == 4 spaces! ; */ 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