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/*
FreeRTOS V8.1.0 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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 modification 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. !<<
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. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
#include "PriorityDefinitions.h"
PUBLIC _prvStartFirstTask
PUBLIC ___interrupt_27
EXTERN _pxCurrentTCB
EXTERN _vTaskSwitchContext
RSEG CODE:CODE(4)
_prvStartFirstTask:
/* When starting the scheduler there is nothing that needs moving to the
interrupt stack because the function is not called from an interrupt.
Just ensure the current stack is the user stack. */
SETPSW U
/* Obtain the location of the stack associated with which ever task
pxCurrentTCB is currently pointing to. */
MOV.L #_pxCurrentTCB, R15
MOV.L [R15], R15
MOV.L [R15], R0
/* Restore the registers from the stack of the task pointed to by
pxCurrentTCB. */
POP R15
/* Accumulator low 32 bits. */
MVTACLO R15
POP R15
/* Accumulator high 32 bits. */
MVTACHI R15
POP R15
/* Floating point status word. */
MVTC R15, FPSW
/* R1 to R15 - R0 is not included as it is the SP. */
POPM R1-R15
/* This pops the remaining registers. */
RTE
NOP
NOP
/*-----------------------------------------------------------*/
/* The software interrupt - overwrite the default 'weak' definition. */
___interrupt_27:
/* Re-enable interrupts. */
SETPSW I
/* Move the data that was automatically pushed onto the interrupt stack when
the interrupt occurred from the interrupt stack to the user stack.
R15 is saved before it is clobbered. */
PUSH.L R15
/* Read the user stack pointer. */
MVFC USP, R15
/* Move the address down to the data being moved. */
SUB #12, R15
MVTC R15, USP
/* Copy the data across, R15, then PC, then PSW. */
MOV.L [ R0 ], [ R15 ]
MOV.L 4[ R0 ], 4[ R15 ]
MOV.L 8[ R0 ], 8[ R15 ]
/* Move the interrupt stack pointer to its new correct position. */
ADD #12, R0
/* All the rest of the registers are saved directly to the user stack. */
SETPSW U
/* Save the rest of the general registers (R15 has been saved already). */
PUSHM R1-R14
/* Save the FPSW and accumulator. */
MVFC FPSW, R15
PUSH.L R15
MVFACHI R15
PUSH.L R15
/* Middle word. */
MVFACMI R15
/* Shifted left as it is restored to the low order word. */
SHLL #16, R15
PUSH.L R15
/* Save the stack pointer to the TCB. */
MOV.L #_pxCurrentTCB, R15
MOV.L [ R15 ], R15
MOV.L R0, [ R15 ]
/* Ensure the interrupt mask is set to the syscall priority while the kernel
structures are being accessed. */
MVTIPL #configMAX_SYSCALL_INTERRUPT_PRIORITY
/* Select the next task to run. */
BSR.A _vTaskSwitchContext
/* Reset the interrupt mask as no more data structure access is required. */
MVTIPL #configKERNEL_INTERRUPT_PRIORITY
/* Load the stack pointer of the task that is now selected as the Running
state task from its TCB. */
MOV.L #_pxCurrentTCB,R15
MOV.L [ R15 ], R15
MOV.L [ R15 ], R0
/* Restore the context of the new task. The PSW (Program Status Word) and
PC will be popped by the RTE instruction. */
POP R15
MVTACLO R15
POP R15
MVTACHI R15
POP R15
MVTC R15, FPSW
POPM R1-R15
RTE
NOP
NOP
/*-----------------------------------------------------------*/
END