/* FreeRTOS V8.2.2 - Copyright (C) 2015 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. 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 on the following link: http://www.freertos.org/a00114.html *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that is more than just the market leader, it * * is the industry's de facto standard. * * * * Help yourself get started quickly while simultaneously helping * * to support the FreeRTOS project by purchasing a FreeRTOS * * tutorial book, reference manual, or both: * * http://www.FreeRTOS.org/Documentation * * * *************************************************************************** http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading the FAQ page "My application does not run, what could be wrong?". Have you defined configASSERT()? http://www.FreeRTOS.org/support - In return for receiving this top quality embedded software for free we request you assist our global community by participating in the support forum. http://www.FreeRTOS.org/training - Investing in training allows your team to be as productive as possible as early as possible. Now you can receive FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers Ltd, and the world's leading authority on the world's leading RTOS. 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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and commercial 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! */ /* GCC/HCS12 port by Jefferson L Smith, 2005 */ /* Scheduler includes. */ #include "FreeRTOS.h" #include "task.h" /* Port includes */ #include /*----------------------------------------------------------- * Implementation of functions defined in portable.h for the HCS12 port. *----------------------------------------------------------*/ /* * Configure a timer to generate the RTOS tick at the frequency specified * within FreeRTOSConfig.h. */ static void prvSetupTimerInterrupt( void ); /* NOTE: Interrupt service routines must be in non-banked memory - as does the scheduler startup function. */ #define ATTR_NEAR __attribute__((near)) /* Manual context switch function. This is the SWI ISR. */ // __attribute__((interrupt)) void ATTR_NEAR vPortYield( void ); /* Tick context switch function. This is the timer ISR. */ // __attribute__((interrupt)) void ATTR_NEAR vPortTickInterrupt( void ); /* Function in non-banked memory which actually switches to first task. */ BaseType_t ATTR_NEAR xStartSchedulerNear( void ); /* Calls to portENTER_CRITICAL() can be nested. When they are nested the critical section should not be left (i.e. interrupts should not be re-enabled) until the nesting depth reaches 0. This variable simply tracks the nesting depth. Each task maintains it's own critical nesting depth variable so uxCriticalNesting is saved and restored from the task stack during a context switch. */ volatile UBaseType_t uxCriticalNesting = 0x80; // un-initialized /*-----------------------------------------------------------*/ /* * See header file for description. */ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters ) { /* Setup the initial stack of the task. The stack is set exactly as expected by the portRESTORE_CONTEXT() macro. In this case the stack as expected by the HCS12 RTI instruction. */ /* The address of the task function is placed in the stack byte at a time. */ *pxTopOfStack = ( StackType_t ) *( ((StackType_t *) (&pxCode) ) + 1 ); *--pxTopOfStack = ( StackType_t ) *( ((StackType_t *) (&pxCode) ) + 0 ); /* Next are all the registers that form part of the task context. */ /* Y register */ *--pxTopOfStack = ( StackType_t ) 0xff; *--pxTopOfStack = ( StackType_t ) 0xee; /* X register */ *--pxTopOfStack = ( StackType_t ) 0xdd; *--pxTopOfStack = ( StackType_t ) 0xcc; /* A register contains parameter high byte. */ *--pxTopOfStack = ( StackType_t ) *( ((StackType_t *) (&pvParameters) ) + 0 ); /* B register contains parameter low byte. */ *--pxTopOfStack = ( StackType_t ) *( ((StackType_t *) (&pvParameters) ) + 1 ); /* CCR: Note that when the task starts interrupts will be enabled since "I" bit of CCR is cleared */ *--pxTopOfStack = ( StackType_t ) 0x80; // keeps Stop disabled (MCU default) /* tmp softregs used by GCC. Values right now don't matter. */ __asm("\n\ movw _.frame, 2,-%0 \n\ movw _.tmp, 2,-%0 \n\ movw _.z, 2,-%0 \n\ movw _.xy, 2,-%0 \n\ ;movw _.d2, 2,-%0 \n\ ;movw _.d1, 2,-%0 \n\ ": "=A"(pxTopOfStack) : "0"(pxTopOfStack) ); #ifdef BANKED_MODEL /* The page of the task. */ *--pxTopOfStack = 0x30; // can only directly start in PPAGE 0x30 #endif /* The critical nesting depth is initialised with 0 (meaning not in a critical section). */ *--pxTopOfStack = ( StackType_t ) 0x00; return pxTopOfStack; } /*-----------------------------------------------------------*/ void vPortEndScheduler( void ) { /* It is unlikely that the HCS12 port will get stopped. */ } /*-----------------------------------------------------------*/ static void prvSetupTimerInterrupt( void ) { /* Enable hardware RTI timer */ /* Ignores configTICK_RATE_HZ */ RTICTL = 0x50; // 16 MHz xtal: 976.56 Hz, 1024mS CRGINT |= 0x80; // RTIE } /*-----------------------------------------------------------*/ BaseType_t xPortStartScheduler( void ) { /* xPortStartScheduler() does not start the scheduler directly because the header file containing the xPortStartScheduler() prototype is part of the common kernel code, and therefore cannot use the CODE_SEG pragma. Instead it simply calls the locally defined xNearStartScheduler() - which does use the CODE_SEG pragma. */ int16_t register d; __asm ("jmp xStartSchedulerNear ; will never return": "=d"(d)); return d; } /*-----------------------------------------------------------*/ BaseType_t xStartSchedulerNear( void ) { /* Configure the timer that will generate the RTOS tick. Interrupts are disabled when this function is called. */ prvSetupTimerInterrupt(); /* Restore the context of the first task. */ portRESTORE_CONTEXT(); portISR_TAIL(); /* Should not get here! */ return pdFALSE; } /*-----------------------------------------------------------*/ /* * Context switch functions. These are interrupt service routines. */ /* * Manual context switch forced by calling portYIELD(). This is the SWI * handler. */ void vPortYield( void ) { portISR_HEAD(); /* NOTE: This is the trap routine (swi) although not defined as a trap. It will fill the stack the same way as an ISR in order to mix preemtion and cooperative yield. */ portSAVE_CONTEXT(); vTaskSwitchContext(); portRESTORE_CONTEXT(); portISR_TAIL(); } /*-----------------------------------------------------------*/ /* * RTOS tick interrupt service routine. If the cooperative scheduler is * being used then this simply increments the tick count. If the * preemptive scheduler is being used a context switch can occur. */ void vPortTickInterrupt( void ) { portISR_HEAD(); /* Clear tick timer flag */ CRGFLG = 0x80; #if configUSE_PREEMPTION == 1 { /* A context switch might happen so save the context. */ portSAVE_CONTEXT(); /* Increment the tick ... */ if( xTaskIncrementTick() != pdFALSE ) { /* A context switch is necessary. */ vTaskSwitchContext(); } /* Restore the context of a task - which may be a different task to that interrupted. */ portRESTORE_CONTEXT(); } #else { xTaskIncrementTick(); } #endif portISR_TAIL(); }