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;/*
; FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 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 (version 2) as published
; by the Free Software Foundation and modified by the FreeRTOS exception.
;
; 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 is included to allow you 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.
;
;
; ***************************************************************************
; * *
; * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
; * *
; * This is a concise, step by step, 'hands on' guide that describes both *
; * general multitasking concepts and FreeRTOS specifics. It presents and *
; * explains numerous examples that are written using the FreeRTOS API. *
; * Full source code for all the examples is provided in an accompanying *
; * .zip file. *
; * *
; ***************************************************************************
;
; 1 tab == 4 spaces!
;
; 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
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