;/* ; FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry. ; ; This file is part of the FreeRTOS.org distribution. ; ; FreeRTOS.org is free software; you can redistribute it and/or modify ; it under the terms of the GNU General Public License as published by ; the Free Software Foundation; either version 2 of the License, or ; (at your option) any later version. ; ; FreeRTOS.org 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 ; along with FreeRTOS.org; if not, write to the Free Software ; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ; ; A special exception to the GPL can be applied should you wish to distribute ; a combined work that includes FreeRTOS.org, without being obliged to provide ; the source code for any proprietary components. See the licensing section ; of http://www.FreeRTOS.org for full details of how and when the exception ; can be applied. ; ; *************************************************************************** ; *************************************************************************** ; * * ; * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, * ; * and even write all or part of your application on your behalf. * ; * See http://www.OpenRTOS.com for details of the services we provide to * ; * expedite your project. * ; * * ; *************************************************************************** ; *************************************************************************** ; ; Please ensure to read the configuration and relevant port sections of the ; online documentation. ; ; 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. ;*/ IMPORT ulCriticalNesting ; IMPORT pxCurrentTCB ; MACRO portRESTORE_CONTEXT LDR R0, =pxCurrentTCB ; Set the LR to the task stack. The location was... LDR R0, [R0] ; ... stored in pxCurrentTCB LDR LR, [R0] LDR R0, =ulCriticalNesting ; The critical nesting depth is the first item on... LDMFD LR!, {R1} ; ...the stack. Load it into the ulCriticalNesting var. STR R1, [R0] ; LDMFD LR!, {R0} ; Get the SPSR from the stack. MSR SPSR_cxsf, R0 ; LDMFD LR, {R0-R14}^ ; Restore all system mode registers for the task. NOP ; LDR LR, [LR, #+60] ; Restore the return address ; And return - correcting the offset in the LR to obtain ... SUBS PC, LR, #4 ; ...the correct address. MEND ; /**********************************************************************/ MACRO portSAVE_CONTEXT STMDB SP!, {R0} ; Store R0 first as we need to use it. STMDB SP,{SP}^ ; Set R0 to point to the task stack pointer. NOP ; SUB SP, SP, #4 ; LDMIA SP!,{R0} ; STMDB R0!, {LR} ; Push the return address onto the stack. MOV LR, R0 ; Now we have saved LR we can use it instead of R0. LDMIA SP!, {R0} ; Pop R0 so we can save it onto the system mode stack. STMDB LR,{R0-LR}^ ; Push all the system mode registers onto the task stack. NOP ; SUB LR, LR, #60 ; MRS R0, SPSR ; Push the SPSR onto the task stack. STMDB LR!, {R0} ; LDR R0, =ulCriticalNesting ; LDR R0, [R0] ; STMDB LR!, {R0} ; LDR R0, =pxCurrentTCB ; Store the new top of stack for the task. LDR R1, [R0] ; STR LR, [R1] ; MEND END