2 ; FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd.
\r
5 ; ***************************************************************************
\r
7 ; * FreeRTOS tutorial books are available in pdf and paperback. *
\r
8 ; * Complete, revised, and edited pdf reference manuals are also *
\r
11 ; * Purchasing FreeRTOS documentation will not only help you, by *
\r
12 ; * ensuring you get running as quickly as possible and with an *
\r
13 ; * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
14 ; * the FreeRTOS project to continue with its mission of providing *
\r
15 ; * professional grade, cross platform, de facto standard solutions *
\r
16 ; * for microcontrollers - completely free of charge! *
\r
18 ; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
20 ; * Thank you for using FreeRTOS, and thank you for your support! *
\r
22 ; ***************************************************************************
\r
25 ; This file is part of the FreeRTOS distribution.
\r
27 ; FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 ; the terms of the GNU General Public License (version 2) as published by the
\r
29 ; Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 ; >>>NOTE<<< The modification to the GPL is included to allow you to
\r
31 ; distribute a combined work that includes FreeRTOS without being obliged to
\r
32 ; provide the source code for proprietary components outside of the FreeRTOS
\r
33 ; kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
34 ; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
35 ; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 ; more details. You should have received a copy of the GNU General Public
\r
37 ; License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 ; can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 ; by writing to Richard Barry, contact details for whom are available on the
\r
40 ; FreeRTOS WEB site.
\r
42 ; 1 tab == 4 spaces!
\r
44 ; http://www.FreeRTOS.org - Documentation, latest information, license and
\r
47 ; http://www.SafeRTOS.com - A version that is certified for use in safety
\r
50 ; http://www.OpenRTOS.com - Commercial support, development, porting,
\r
51 ; licensing and training services.
\r
54 EXTERN ulCriticalNesting
\r
56 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
\r
57 ; Context save and restore macro definitions
\r
58 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
\r
60 portSAVE_CONTEXT MACRO
\r
62 ; Push R0 as we are going to use the register.
\r
65 ; Set R0 to point to the task stack pointer.
\r
71 ; Push the return address onto the stack.
\r
74 ; Now we have saved LR we can use it instead of R0.
\r
77 ; Pop R0 so we can save it onto the system mode stack.
\r
80 ; Push all the system mode registers onto the task stack.
\r
85 ; Push the SPSR onto the task stack.
\r
89 LDR R0, =ulCriticalNesting
\r
93 ; Store the new top of stack for the task.
\r
94 LDR R1, =pxCurrentTCB
\r
101 portRESTORE_CONTEXT MACRO
\r
103 ; Set the LR to the task stack.
\r
104 LDR R1, =pxCurrentTCB
\r
108 ; The critical nesting depth is the first item on the stack.
\r
109 ; Load it into the ulCriticalNesting variable.
\r
110 LDR R0, =ulCriticalNesting
\r
114 ; Get the SPSR from the stack.
\r
118 ; Restore all system mode registers for the task.
\r
119 LDMFD LR, {R0-R14}^
\r
122 ; Restore the return address.
\r
125 ; And return - correcting the offset in the LR to obtain the
\r
126 ; correct address.
\r