/* FreeRTOS V8.0.0 - 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 "FreeRTOS.h" #include "task.h" #include "mb91467d.h" /*-----------------------------------------------------------*/ /* We require the address of the pxCurrentTCB variable, but don't want to know any details of its type. */ typedef void TCB_t; extern volatile TCB_t * volatile pxCurrentTCB; /*-----------------------------------------------------------*/ #pragma asm #macro SaveContext ORCCR #0x20 ;Switch to user stack ST RP,@-R15 ;Store RP STM0 (R7,R6,R5,R4,R3,R2,R1,R0) ;Store R7-R0 STM1 (R14,R13,R12,R11,R10,R9,R8) ;Store R14-R8 ST MDH, @-R15 ;Store MDH ST MDL, @-R15 ;Store MDL ANDCCR #0xDF ;Switch back to system stack LD @R15+,R0 ;Store PC to R0 ORCCR #0x20 ;Switch to user stack ST R0,@-R15 ;Store PC to User stack ANDCCR #0xDF ;Switch back to system stack LD @R15+,R0 ;Store PS to R0 ORCCR #0x20 ;Switch to user stack ST R0,@-R15 ;Store PS to User stack LDI #_pxCurrentTCB, R0 ;Get pxCurrentTCB address LD @R0, R0 ;Get the pxCurrentTCB->pxTopOfStack address ST R15,@R0 ;Store USP to pxCurrentTCB->pxTopOfStack ANDCCR #0xDF ;Switch back to system stack for the rest of tick ISR #endm #macro RestoreContext LDI #_pxCurrentTCB, R0 ;Get pxCurrentTCB address LD @R0, R0 ;Get the pxCurrentTCB->pxTopOfStack address ORCCR #0x20 ;Switch to user stack LD @R0, R15 ;Restore USP from pxCurrentTCB->pxTopOfStack LD @R15+,R0 ;Store PS to R0 ANDCCR #0xDF ;Switch to system stack ST R0,@-R15 ;Store PS to system stack ORCCR #0x20 ;Switch to user stack LD @R15+,R0 ;Store PC to R0 ANDCCR #0xDF ;Switch to system stack ST R0,@-R15 ;Store PC to system stack ORCCR #0x20 ;Switch back to retrieve the remaining context LD @R15+, MDL ;Restore MDL LD @R15+, MDH ;Restore MDH LDM1 (R14,R13,R12,R11,R10,R9,R8) ;Restore R14-R8 LDM0 (R7,R6,R5,R4,R3,R2,R1,R0) ;Restore R7-R0 LD @R15+, RP ;Restore RP ANDCCR #0xDF ;Switch back to system stack for the rest of tick ISR #endm #pragma endasm /*-----------------------------------------------------------*/ /* * Perform hardware setup to enable ticks from timer 1, */ static void prvSetupTimerInterrupt( void ); /*-----------------------------------------------------------*/ /* * Initialise the stack of a task to look exactly as if a call to * portSAVE_CONTEXT had been called. * * See the header file portable.h. */ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters ) { /* Place a few bytes of known values on the bottom of the stack. This is just useful for debugging. */ *pxTopOfStack = 0x11111111; pxTopOfStack--; *pxTopOfStack = 0x22222222; pxTopOfStack--; *pxTopOfStack = 0x33333333; pxTopOfStack--; /* This is a redundant push to the stack, it may be required if in some implementations of the compiler the parameter to the task is passed on to the stack rather than in R4 register. */ *pxTopOfStack = (StackType_t)(pvParameters); pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00000000; /* RP */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00007777; /* R7 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00006666; /* R6 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00005555; /* R5 */ pxTopOfStack--; /* In the current implementation of the compiler the first parameter to the task (or function) is passed via R4 parameter to the task, hence the pvParameters pointer is copied into the R4 register. See compiler manual section 4.6.2 for more information. */ *pxTopOfStack = ( StackType_t ) (pvParameters); /* R4 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00003333; /* R3 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00002222; /* R2 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00001111; /* R1 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00000001; /* R0 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x0000EEEE; /* R14 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x0000DDDD; /* R13 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x0000CCCC; /* R12 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x0000BBBB; /* R11 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x0000AAAA; /* R10 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00009999; /* R9 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x00008888; /* R8 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x11110000; /* MDH */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x22220000; /* MDL */ pxTopOfStack--; /* The start of the task code. */ *pxTopOfStack = ( StackType_t ) pxCode; /* PC */ pxTopOfStack--; /* PS - User Mode, USP, ILM=31, Interrupts enabled */ *pxTopOfStack = ( StackType_t ) 0x001F0030; /* PS */ return pxTopOfStack; } /*-----------------------------------------------------------*/ BaseType_t xPortStartScheduler( void ) { /* Setup the hardware to generate the tick. */ prvSetupTimerInterrupt(); /* Restore the context of the first task that is going to run. */ #pragma asm RestoreContext #pragma endasm /* Simulate a function call end as generated by the compiler. We will now jump to the start of the task the context of which we have just restored. */ __asm(" reti "); /* Should not get here. */ return pdFAIL; } /*-----------------------------------------------------------*/ void vPortEndScheduler( void ) { /* Not implemented - unlikely to ever be required as there is nothing to return to. */ } /*-----------------------------------------------------------*/ static void prvSetupTimerInterrupt( void ) { /* The peripheral clock divided by 32 is used by the timer. */ const uint16_t usReloadValue = ( uint16_t ) ( ( ( configPER_CLOCK_HZ / configTICK_RATE_HZ ) / 32UL ) - 1UL ); /* Setup RLT0 to generate a tick interrupt. */ TMCSR0_CNTE = 0; /* Count Disable */ TMCSR0_CSL = 0x2; /* CLKP/32 */ TMCSR0_MOD = 0; /* Software trigger */ TMCSR0_RELD = 1; /* Reload */ TMCSR0_UF = 0; /* Clear underflow flag */ TMRLR0 = usReloadValue; TMCSR0_INTE = 1; /* Interrupt Enable */ TMCSR0_CNTE = 1; /* Count Enable */ TMCSR0_TRG = 1; /* Trigger */ PORTEN = 0x3; /* Port Enable */ } /*-----------------------------------------------------------*/ #if configUSE_PREEMPTION == 1 /* * Tick ISR for preemptive scheduler. The tick count is incremented * after the context is saved. Then the context is switched if required, * and last the context of the task which is to be resumed is restored. */ #pragma asm .global _ReloadTimer0_IRQHandler _ReloadTimer0_IRQHandler: ANDCCR #0xEF ;Disable Interrupts SaveContext ;Save context ORCCR #0x10 ;Re-enable Interrupts LDI #0xFFFB,R1 LDI #_tmcsr0, R0 AND R1,@R0 ;Clear RLT0 interrupt flag CALL32 _xTaskIncrementTick,R12 ;Increment Tick CALL32 _vTaskSwitchContext,R12 ;Switch context if required ANDCCR #0xEF ;Disable Interrupts RestoreContext ;Restore context ORCCR #0x10 ;Re-enable Interrupts RETI #pragma endasm #else /* * Tick ISR for the cooperative scheduler. All this does is increment the * tick count. We don't need to switch context, this can only be done by * manual calls to taskYIELD(); */ __interrupt void ReloadTimer0_IRQHandler( void ) { /* Clear RLT0 interrupt flag */ TMCSR0_UF = 0; xTaskIncrementTick(); } #endif /* * Manual context switch. We can use a __nosavereg attribute as the context * would be saved by PortSAVE_CONTEXT(). The context is switched and then * the context of the new task is restored saved. */ #pragma asm .global _vPortYieldDelayed _vPortYieldDelayed: ANDCCR #0xEF ;Disable Interrupts SaveContext ;Save context ORCCR #0x10 ;Re-enable Interrupts LDI #_dicr, R0 BANDL #0x0E, @R0 ;Clear Delayed interrupt flag CALL32 _vTaskSwitchContext,R12 ;Switch context if required ANDCCR #0xEF ;Disable Interrupts RestoreContext ;Restore context ORCCR #0x10 ;Re-enable Interrupts RETI #pragma endasm /*-----------------------------------------------------------*/ /* * Manual context switch. We can use a __nosavereg attribute as the context * would be saved by PortSAVE_CONTEXT(). The context is switched and then * the context of the new task is restored saved. */ #pragma asm .global _vPortYield _vPortYield: SaveContext ;Save context CALL32 _vTaskSwitchContext,R12 ;Switch context if required RestoreContext ;Restore context RETI #pragma endasm /*-----------------------------------------------------------*/