blob: 9d372915fa7f62fae19ae3ffb7630c9bfdbc5cb5 [file] [log] [blame]
;/*
; FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.
;
; 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 exception 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.
; Alternative commercial license and support terms are also available upon
; request. See the licensing section of http://www.FreeRTOS.org for full
; license details.
;
; 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 along
; with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
; Temple Place, Suite 330, Boston, MA 02111-1307 USA.
;
;
; ***************************************************************************
; * *
; * The FreeRTOS eBook and reference manual are available to purchase for a *
; * small fee. Help yourself get started quickly while also helping the *
; * FreeRTOS project! See http://www.FreeRTOS.org/Documentation for details *
; * *
; ***************************************************************************
;
; 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.
;*/
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