mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
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202 lines
7 KiB
ArmAsm
202 lines
7 KiB
ArmAsm
/*
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FreeRTOS V9.0.0rc2 - Copyright (C) 2016 Real Time Engineers Ltd.
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All rights reserved
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VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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This file is part of the FreeRTOS distribution.
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FreeRTOS is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License (version 2) as published by the
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Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.
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***************************************************************************
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>>! NOTE: The modification to the GPL is included to allow you to !<<
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>>! distribute a combined work that includes FreeRTOS without being !<<
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>>! obliged to provide the source code for proprietary components !<<
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>>! outside of the FreeRTOS kernel. !<<
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***************************************************************************
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FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. Full license text is available on the following
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link: http://www.freertos.org/a00114.html
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***************************************************************************
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* *
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* FreeRTOS provides completely free yet professionally developed, *
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* robust, strictly quality controlled, supported, and cross *
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* platform software that is more than just the market leader, it *
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* is the industry's de facto standard. *
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* *
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* Help yourself get started quickly while simultaneously helping *
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* to support the FreeRTOS project by purchasing a FreeRTOS *
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* tutorial book, reference manual, or both: *
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* http://www.FreeRTOS.org/Documentation *
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* *
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***************************************************************************
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http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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the FAQ page "My application does not run, what could be wrong?". Have you
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defined configASSERT()?
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http://www.FreeRTOS.org/support - In return for receiving this top quality
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embedded software for free we request you assist our global community by
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participating in the support forum.
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http://www.FreeRTOS.org/training - Investing in training allows your team to
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be as productive as possible as early as possible. Now you can receive
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FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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Ltd, and the world's leading authority on the world's leading RTOS.
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http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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compatible FAT file system, and our tiny thread aware UDP/IP stack.
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http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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licenses offer ticketed support, indemnification and commercial middleware.
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http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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engineered and independently SIL3 certified version for use in safety and
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mission critical applications that require provable dependability.
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1 tab == 4 spaces!
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*/
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#include "PriorityDefinitions.h"
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PUBLIC _prvStartFirstTask
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PUBLIC ___interrupt_27
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EXTERN _pxCurrentTCB
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EXTERN _vTaskSwitchContext
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RSEG CODE:CODE(4)
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_prvStartFirstTask:
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/* When starting the scheduler there is nothing that needs moving to the
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interrupt stack because the function is not called from an interrupt.
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Just ensure the current stack is the user stack. */
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SETPSW U
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/* Obtain the location of the stack associated with which ever task
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pxCurrentTCB is currently pointing to. */
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MOV.L #_pxCurrentTCB, R15
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MOV.L [R15], R15
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MOV.L [R15], R0
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/* Restore the registers from the stack of the task pointed to by
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pxCurrentTCB. */
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POP R15
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/* Accumulator low 32 bits. */
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MVTACLO R15
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POP R15
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/* Accumulator high 32 bits. */
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MVTACHI R15
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POP R15
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/* Floating point status word. */
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MVTC R15, FPSW
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/* R1 to R15 - R0 is not included as it is the SP. */
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POPM R1-R15
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/* This pops the remaining registers. */
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RTE
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NOP
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NOP
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/*-----------------------------------------------------------*/
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/* The software interrupt - overwrite the default 'weak' definition. */
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___interrupt_27:
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/* Re-enable interrupts. */
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SETPSW I
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/* Move the data that was automatically pushed onto the interrupt stack when
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the interrupt occurred from the interrupt stack to the user stack.
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R15 is saved before it is clobbered. */
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PUSH.L R15
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/* Read the user stack pointer. */
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MVFC USP, R15
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/* Move the address down to the data being moved. */
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SUB #12, R15
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MVTC R15, USP
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/* Copy the data across, R15, then PC, then PSW. */
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MOV.L [ R0 ], [ R15 ]
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MOV.L 4[ R0 ], 4[ R15 ]
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MOV.L 8[ R0 ], 8[ R15 ]
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/* Move the interrupt stack pointer to its new correct position. */
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ADD #12, R0
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/* All the rest of the registers are saved directly to the user stack. */
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SETPSW U
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/* Save the rest of the general registers (R15 has been saved already). */
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PUSHM R1-R14
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/* Save the FPSW and accumulator. */
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MVFC FPSW, R15
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PUSH.L R15
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MVFACHI R15
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PUSH.L R15
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/* Middle word. */
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MVFACMI R15
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/* Shifted left as it is restored to the low order word. */
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SHLL #16, R15
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PUSH.L R15
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/* Save the stack pointer to the TCB. */
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MOV.L #_pxCurrentTCB, R15
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MOV.L [ R15 ], R15
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MOV.L R0, [ R15 ]
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/* Ensure the interrupt mask is set to the syscall priority while the kernel
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structures are being accessed. */
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MVTIPL #configMAX_SYSCALL_INTERRUPT_PRIORITY
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/* Select the next task to run. */
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BSR.A _vTaskSwitchContext
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/* Reset the interrupt mask as no more data structure access is required. */
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MVTIPL #configKERNEL_INTERRUPT_PRIORITY
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/* Load the stack pointer of the task that is now selected as the Running
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state task from its TCB. */
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MOV.L #_pxCurrentTCB,R15
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MOV.L [ R15 ], R15
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MOV.L [ R15 ], R0
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/* Restore the context of the new task. The PSW (Program Status Word) and
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PC will be popped by the RTE instruction. */
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POP R15
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MVTACLO R15
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POP R15
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MVTACHI R15
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POP R15
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MVTC R15, FPSW
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POPM R1-R15
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RTE
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NOP
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NOP
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/*-----------------------------------------------------------*/
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END
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