| ;/* | |
| ; FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd. | |
| ; | |
| ; | |
| ; *************************************************************************** | |
| ; * * | |
| ; * FreeRTOS tutorial books are available in pdf and paperback. * | |
| ; * Complete, revised, and edited pdf reference manuals are also * | |
| ; * available. * | |
| ; * * | |
| ; * Purchasing FreeRTOS documentation will not only help you, by * | |
| ; * ensuring you get running as quickly as possible and with an * | |
| ; * in-depth knowledge of how to use FreeRTOS, it will also help * | |
| ; * the FreeRTOS project to continue with its mission of providing * | |
| ; * professional grade, cross platform, de facto standard solutions * | |
| ; * for microcontrollers - completely free of charge! * | |
| ; * * | |
| ; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
| ; * * | |
| ; * Thank you for using FreeRTOS, and thank you for your support! * | |
| ; * * | |
| ; *************************************************************************** | |
| ; | |
| ; | |
| ; This file is part of the FreeRTOS distribution. | |
| ; | |
| ; FreeRTOS is free software; you can redistribute it and/or modify it under | |
| ; the terms of the GNU General Public License (version 2) as published by the | |
| ; Free Software Foundation AND MODIFIED BY the FreeRTOS exception. | |
| ; >>>NOTE<<< The modification to the GPL is included to allow you to | |
| ; distribute a combined work that includes FreeRTOS without being obliged to | |
| ; provide the source code for proprietary components outside of the FreeRTOS | |
| ; kernel. FreeRTOS is distributed in the hope that it will be useful, but | |
| ; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
| ; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| ; more details. You should have received a copy of the GNU General Public | |
| ; License and the FreeRTOS license exception along with FreeRTOS; if not it | |
| ; can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
| ; by writing to Richard Barry, contact details for whom are available on the | |
| ; FreeRTOS WEB site. | |
| ; | |
| ; 1 tab == 4 spaces! | |
| ; | |
| ; http://www.FreeRTOS.org - Documentation, latest information, license and | |
| ; contact details. | |
| ; | |
| ; http://www.SafeRTOS.com - A version that is certified for use in safety | |
| ; critical systems. | |
| ; | |
| ; http://www.OpenRTOS.com - Commercial support, development, porting, | |
| ; licensing and training services. | |
| ;*/ | |
| EXTERN pxCurrentTCB | |
| EXTERN ulCriticalNesting | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ; Context save and restore macro definitions | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| portSAVE_CONTEXT MACRO | |
| ; Push R0 as we are going to use the register. | |
| STMDB SP!, {R0} | |
| ; Set R0 to point to the task stack pointer. | |
| STMDB SP, {SP}^ | |
| NOP | |
| SUB SP, SP, #4 | |
| LDMIA SP!, {R0} | |
| ; Push the return address onto the stack. | |
| STMDB R0!, {LR} | |
| ; Now we have saved LR we can use it instead of R0. | |
| MOV LR, R0 | |
| ; Pop R0 so we can save it onto the system mode stack. | |
| LDMIA SP!, {R0} | |
| ; Push all the system mode registers onto the task stack. | |
| STMDB LR, {R0-LR}^ | |
| NOP | |
| SUB LR, LR, #60 | |
| ; Push the SPSR onto the task stack. | |
| MRS R0, SPSR | |
| STMDB LR!, {R0} | |
| LDR R0, =ulCriticalNesting | |
| LDR R0, [R0] | |
| STMDB LR!, {R0} | |
| ; Store the new top of stack for the task. | |
| LDR R1, =pxCurrentTCB | |
| LDR R0, [R1] | |
| STR LR, [R0] | |
| ENDM | |
| portRESTORE_CONTEXT MACRO | |
| ; Set the LR to the task stack. | |
| LDR R1, =pxCurrentTCB | |
| LDR R0, [R1] | |
| LDR LR, [R0] | |
| ; The critical nesting depth is the first item on the stack. | |
| ; Load it into the ulCriticalNesting variable. | |
| LDR R0, =ulCriticalNesting | |
| LDMFD LR!, {R1} | |
| STR R1, [R0] | |
| ; Get the SPSR from the stack. | |
| LDMFD LR!, {R0} | |
| MSR SPSR_cxsf, R0 | |
| ; Restore all system mode registers for the task. | |
| LDMFD LR, {R0-R14}^ | |
| NOP | |
| ; Restore the return address. | |
| LDR LR, [LR, #+60] | |
| ; And return - correcting the offset in the LR to obtain the | |
| ; correct address. | |
| SUBS PC, LR, #4 | |
| ENDM | |