| /* | |
| FreeRTOS V6.1.0 - Copyright (C) 2010 Real Time Engineers Ltd. | |
| *************************************************************************** | |
| * * | |
| * If you are: * | |
| * * | |
| * + New to FreeRTOS, * | |
| * + Wanting to learn FreeRTOS or multitasking in general quickly * | |
| * + Looking for basic training, * | |
| * + Wanting to improve your FreeRTOS skills and productivity * | |
| * * | |
| * then take a look at the FreeRTOS books - available as PDF or paperback * | |
| * * | |
| * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * | |
| * http://www.FreeRTOS.org/Documentation * | |
| * * | |
| * A pdf reference manual is also available. Both are usually delivered * | |
| * to your inbox within 20 minutes to two hours when purchased between 8am * | |
| * and 8pm GMT (although please allow up to 24 hours in case of * | |
| * exceptional circumstances). 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 exception 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 Richard Barry, contact details for whom are available on the | |
| FreeRTOS WEB site. | |
| 1 tab == 4 spaces! | |
| 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. | |
| */ | |
| #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 | |