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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.
*/
/*
Change from V4.2.1:
+ Introduced usage of configKERNEL_INTERRUPT_PRIORITY macro to set the
interrupt priority used by the kernel.
*/
#include <FreeRTOSConfig.h>
/* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is
defined. The value zero should also ensure backward compatibility.
FreeRTOS.org versions prior to V4.3.0 did not include this definition. */
#ifndef configKERNEL_INTERRUPT_PRIORITY
#define configKERNEL_INTERRUPT_PRIORITY 0
#endif
RSEG CODE:CODE(2)
thumb
EXTERN vPortYieldFromISR
EXTERN pxCurrentTCB
EXTERN vTaskSwitchContext
PUBLIC vSetMSP
PUBLIC xPortPendSVHandler
PUBLIC vPortSetInterruptMask
PUBLIC vPortClearInterruptMask
PUBLIC vPortSVCHandler
PUBLIC vPortStartFirstTask
/*-----------------------------------------------------------*/
vSetMSP
msr msp, r0
bx lr
/*-----------------------------------------------------------*/
xPortPendSVHandler:
mrs r0, psp
ldr r3, =pxCurrentTCB /* Get the location of the current TCB. */
ldr r2, [r3]
stmdb r0!, {r4-r11} /* Save the remaining registers. */
str r0, [r2] /* Save the new top of stack into the first member of the TCB. */
stmdb sp!, {r3, r14}
mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
msr basepri, r0
bl vTaskSwitchContext
mov r0, #0
msr basepri, r0
ldmia sp!, {r3, r14}
ldr r1, [r3]
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
ldmia r0!, {r4-r11} /* Pop the registers. */
msr psp, r0
bx r14
/*-----------------------------------------------------------*/
vPortSetInterruptMask:
push { r0 }
mov R0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
msr BASEPRI, R0
pop { R0 }
bx r14
/*-----------------------------------------------------------*/
vPortClearInterruptMask:
PUSH { r0 }
MOV R0, #0
MSR BASEPRI, R0
POP { R0 }
bx r14
/*-----------------------------------------------------------*/
vPortSVCHandler;
ldr r3, =pxCurrentTCB
ldr r1, [r3]
ldr r0, [r1]
ldmia r0!, {r4-r11}
msr psp, r0
mov r0, #0
msr basepri, r0
orr r14, r14, #13
bx r14
/*-----------------------------------------------------------*/
vPortStartFirstTask
/* Use the NVIC offset register to locate the stack. */
ldr r0, =0xE000ED08
ldr r0, [r0]
ldr r0, [r0]
/* Set the msp back to the start of the stack. */
msr msp, r0
/* Call SVC to start the first task. */
svc 0
END
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