/* FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd. FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS tutorial books are available in pdf and paperback. * * Complete, revised, and edited pdf reference manuals are also * * available. * * * * Purchasing FreeRTOS documentation will not only help you, by * * ensuring you get running as quickly as possible and with an * * in-depth knowledge of how to use FreeRTOS, it will also help * * the FreeRTOS project to continue with its mission of providing * * professional grade, cross platform, de facto standard solutions * * for microcontrollers - completely free of charge! * * * * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * * * * Thank you for using FreeRTOS, and thank you for your support! * * * *************************************************************************** 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. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License and the FreeRTOS license exception along with FreeRTOS; if not it can be viewed here: http://www.freertos.org/a00114.html and also obtained by writing to Real Time Engineers Ltd., contact details for whom are available on the FreeRTOS WEB site. 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, and our new fully thread aware and reentrant UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell the code with commercial support, indemnification and middleware, under the OpenRTOS brand. 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. */ #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