/* FreeRTOS V7.5.2 - Copyright (C) 2013 Real Time Engineers Ltd. 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! */ /*----------------------------------------------------------- * Implementation of functions defined in portable.h for the NIOS2 port. *----------------------------------------------------------*/ /* Standard Includes. */ #include #include /* Altera includes. */ #include "sys/alt_irq.h" #include "altera_avalon_timer_regs.h" #include "priv/alt_irq_table.h" /* Scheduler includes. */ #include "FreeRTOS.h" #include "task.h" /* Interrupts are enabled. */ #define portINITIAL_ESTATUS ( portSTACK_TYPE ) 0x01 /*-----------------------------------------------------------*/ /* * Setup the timer to generate the tick interrupts. */ static void prvSetupTimerInterrupt( void ); /* * Call back for the alarm function. */ void vPortSysTickHandler( void * context, alt_u32 id ); /*-----------------------------------------------------------*/ static void prvReadGp( unsigned long *ulValue ) { asm( "stw gp, (%0)" :: "r"(ulValue) ); } /*-----------------------------------------------------------*/ /* * See header file for description. */ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters ) { portSTACK_TYPE *pxFramePointer = pxTopOfStack - 1; portSTACK_TYPE xGlobalPointer; prvReadGp( &xGlobalPointer ); /* End of stack marker. */ *pxTopOfStack = 0xdeadbeef; pxTopOfStack--; *pxTopOfStack = ( portSTACK_TYPE ) pxFramePointer; pxTopOfStack--; *pxTopOfStack = xGlobalPointer; /* Space for R23 to R16. */ pxTopOfStack -= 9; *pxTopOfStack = ( portSTACK_TYPE ) pxCode; pxTopOfStack--; *pxTopOfStack = portINITIAL_ESTATUS; /* Space for R15 to R5. */ pxTopOfStack -= 12; *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* Space for R3 to R1, muldiv and RA. */ pxTopOfStack -= 5; return pxTopOfStack; } /*-----------------------------------------------------------*/ /* * See header file for description. */ portBASE_TYPE xPortStartScheduler( void ) { /* Start the timer that generates the tick ISR. Interrupts are disabled here already. */ prvSetupTimerInterrupt(); /* Start the first task. */ asm volatile ( " movia r2, restore_sp_from_pxCurrentTCB \n" " jmp r2 " ); /* Should not get here! */ return 0; } /*-----------------------------------------------------------*/ void vPortEndScheduler( void ) { /* It is unlikely that the NIOS2 port will require this function as there is nothing to return to. */ } /*-----------------------------------------------------------*/ /* * Setup the systick timer to generate the tick interrupts at the required * frequency. */ void prvSetupTimerInterrupt( void ) { /* Try to register the interrupt handler. */ if ( -EINVAL == alt_irq_register( SYS_CLK_IRQ, 0x0, vPortSysTickHandler ) ) { /* Failed to install the Interrupt Handler. */ asm( "break" ); } else { /* Configure SysTick to interrupt at the requested rate. */ IOWR_ALTERA_AVALON_TIMER_CONTROL( SYS_CLK_BASE, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK ); IOWR_ALTERA_AVALON_TIMER_PERIODL( SYS_CLK_BASE, ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) & 0xFFFF ); IOWR_ALTERA_AVALON_TIMER_PERIODH( SYS_CLK_BASE, ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) >> 16 ); IOWR_ALTERA_AVALON_TIMER_CONTROL( SYS_CLK_BASE, ALTERA_AVALON_TIMER_CONTROL_CONT_MSK | ALTERA_AVALON_TIMER_CONTROL_START_MSK | ALTERA_AVALON_TIMER_CONTROL_ITO_MSK ); } /* Clear any already pending interrupts generated by the Timer. */ IOWR_ALTERA_AVALON_TIMER_STATUS( SYS_CLK_BASE, ~ALTERA_AVALON_TIMER_STATUS_TO_MSK ); } /*-----------------------------------------------------------*/ void vPortSysTickHandler( void * context, alt_u32 id ) { /* Increment the kernel tick. */ if( xTaskIncrementTick() != pdFALSE ) { vTaskSwitchContext(); } /* Clear the interrupt. */ IOWR_ALTERA_AVALON_TIMER_STATUS( SYS_CLK_BASE, ~ALTERA_AVALON_TIMER_STATUS_TO_MSK ); } /*-----------------------------------------------------------*/ /** This function is a re-implementation of the Altera provided function. * The function is re-implemented to prevent it from enabling an interrupt * when it is registered. Interrupts should only be enabled after the FreeRTOS.org * kernel has its scheduler started so that contexts are saved and switched * correctly. */ int alt_irq_register( alt_u32 id, void* context, void (*handler)(void*, alt_u32) ) { int rc = -EINVAL; alt_irq_context status; if (id < ALT_NIRQ) { /* * interrupts are disabled while the handler tables are updated to ensure * that an interrupt doesn't occur while the tables are in an inconsistent * state. */ status = alt_irq_disable_all (); alt_irq[id].handler = handler; alt_irq[id].context = context; rc = (handler) ? alt_irq_enable (id): alt_irq_disable (id); /* alt_irq_enable_all(status); This line is removed to prevent the interrupt from being immediately enabled. */ } return rc; } /*-----------------------------------------------------------*/