/* FreeRTOS V4.1.1 - Copyright (C) 2003-2006 Richard Barry. MCF5235 Port - Copyright (C) 2006 Christian Walter. 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** as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. 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 along with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA A special exception to the GPL can be applied should you wish to distribute a combined work that includes FreeRTOS, without being obliged to provide the source code for any proprietary components. See the licensing section of http://www.FreeRTOS.org for full details of how and when the exception can be applied. *************************************************************************** *************************************************************************** * * * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * * * * This is a concise, step by step, 'hands on' guide that describes both * * general multitasking concepts and FreeRTOS specifics. It presents and * * explains numerous examples that are written using the FreeRTOS API. * * Full source code for all the examples is provided in an accompanying * * .zip file. * * * *************************************************************************** *************************************************************************** Please ensure to read the configuration and relevant port sections of the online documentation. 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 #include "FreeRTOS.h" #include "FreeRTOSConfig.h" #include "task.h" /* ------------------------ Types ----------------------------------------- */ typedef volatile uint32_t vuint32; typedef volatile uint16_t vuint16; typedef volatile uint8_t vuint8; /* ------------------------ Defines --------------------------------------- */ #define portVECTOR_TABLE __RAMVEC #define portVECTOR_SYSCALL ( 32 + portTRAP_YIELD ) #define portVECTOR_TIMER ( 64 + 36 ) #define MCF_PIT_PRESCALER 512UL #define MCF_PIT_TIMER_TICKS ( FSYS_2 / MCF_PIT_PRESCALER ) #define MCF_PIT_MODULUS_REGISTER(freq) ( MCF_PIT_TIMER_TICKS / ( freq ) - 1UL) #define MCF_PIT_PMR0 ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150002 ] ) ) #define MCF_PIT_PCSR0 ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150000 ] ) ) #define MCF_PIT_PCSR_PRE(x) ( ( ( x ) & 0x000F ) << 8 ) #define MCF_PIT_PCSR_EN ( 0x0001 ) #define MCF_PIT_PCSR_RLD ( 0x0002 ) #define MCF_PIT_PCSR_PIF ( 0x0004 ) #define MCF_PIT_PCSR_PIE ( 0x0008 ) #define MCF_PIT_PCSR_OVW ( 0x0010 ) #define MCF_INTC0_ICR36 ( *( vuint8 * )( void * )( &__IPSBAR[ 0x000C64 ] ) ) #define MCF_INTC0_IMRH ( *( vuint32 * )( void * )( &__IPSBAR[ 0x000C08 ] ) ) #define MCF_INTC0_IMRH_INT_MASK36 ( 0x00000010 ) #define MCF_INTC0_IMRH_MASKALL ( 0x00000001 ) #define MCF_INTC0_ICRn_IP(x) ( ( ( x ) & 0x07 ) << 0 ) #define MCF_INTC0_ICRn_IL(x) ( ( ( x ) & 0x07 ) << 3 ) #define portNO_CRITICAL_NESTING ( ( uint32_t ) 0 ) #define portINITIAL_CRITICAL_NESTING ( ( uint32_t ) 10 ) /* ------------------------ Static variables ------------------------------ */ volatile uint32_t ulCriticalNesting = portINITIAL_CRITICAL_NESTING; /* ------------------------ Static functions ------------------------------ */ #if configUSE_PREEMPTION == 0 static void prvPortPreemptiveTick ( void ) __attribute__ ((interrupt_handler)); #else static void prvPortPreemptiveTick ( void ); #endif /* ------------------------ Start implementation -------------------------- */ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack, TaskFunction_t pxCode, void *pvParameters ) { /* Place the parameter on the stack in the expected location. */ *pxTopOfStack = ( StackType_t ) pvParameters; pxTopOfStack--; /* Place dummy return address on stack. Tasks should never terminate so * we can set this to anything. */ *pxTopOfStack = ( StackType_t ) 0; pxTopOfStack--; /* Create a Motorola Coldfire exception stack frame. First comes the return * address. */ *pxTopOfStack = ( StackType_t ) pxCode; pxTopOfStack--; /* Format, fault-status, vector number for exception stack frame. Task * run in supervisor mode. */ *pxTopOfStack = 0x40002000UL | ( portVECTOR_SYSCALL + 32 ) << 18; pxTopOfStack--; /* Set the initial critical section nesting counter to zero. This value * is used to restore the value of ulCriticalNesting. */ *pxTopOfStack = 0; *pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA6; /* A6 / FP */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA5; /* A5 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA4; /* A4 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA3; /* A3 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA2; /* A2 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA1; /* A1 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xA0; /* A0 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD7; /* D7 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD6; /* D6 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD5; /* D5 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD4; /* D4 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD3; /* D3 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD2; /* D2 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD1; /* D1 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xD0; /* D0 */ return pxTopOfStack; } /* * Called by portYIELD() or taskYIELD() to manually force a context switch. */ static void prvPortYield( void ) { asm volatile ( "move.w #0x2700, %sr\n\t" ); #if _GCC_USES_FP == 1 asm volatile ( "unlk %fp\n\t" ); #endif /* Perform the context switch. First save the context of the current task. */ portSAVE_CONTEXT( ); /* Find the highest priority task that is ready to run. */ vTaskSwitchContext( ); /* Restore the context of the new task. */ portRESTORE_CONTEXT( ); } #if configUSE_PREEMPTION == 0 /* * The ISR used for the scheduler tick depends on whether the cooperative or * the preemptive scheduler is being used. */ static void prvPortPreemptiveTick ( void ) { /* The cooperative scheduler requires a normal IRQ service routine to * simply increment the system tick. */ xTaskIncrementTick(); MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF; } #else static void prvPortPreemptiveTick( void ) { asm volatile ( "move.w #0x2700, %sr\n\t" ); #if _GCC_USES_FP == 1 asm volatile ( "unlk %fp\n\t" ); #endif portSAVE_CONTEXT( ); MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF; if( xTaskIncrementTick() != pdFALSE ) { vTaskSwitchContext( ); } portRESTORE_CONTEXT( ); } #endif void vPortEnterCritical() { /* FIXME: We should store the old IPL here - How are we supposed to do * this. */ ( void )portSET_IPL( portIPL_MAX ); /* Now interrupts are disabled ulCriticalNesting can be accessed * directly. Increment ulCriticalNesting to keep a count of how many times * portENTER_CRITICAL() has been called. */ ulCriticalNesting++; } void vPortExitCritical() { if( ulCriticalNesting > portNO_CRITICAL_NESTING ) { /* Decrement the nesting count as we are leaving a critical section. */ ulCriticalNesting--; /* If the nesting level has reached zero then interrupts should be re-enabled. */ if( ulCriticalNesting == portNO_CRITICAL_NESTING ) { ( void )portSET_IPL( 0 ); } } } BaseType_t xPortStartScheduler( void ) { extern void ( *portVECTOR_TABLE[ ] ) ( ); /* Add entry in vector table for yield system call. */ portVECTOR_TABLE[ portVECTOR_SYSCALL ] = prvPortYield; /* Add entry in vector table for periodic timer. */ portVECTOR_TABLE[ portVECTOR_TIMER ] = prvPortPreemptiveTick; /* Configure the timer for the system clock. */ if ( configTICK_RATE_HZ > 0) { /* Configure prescaler */ MCF_PIT_PCSR0 = MCF_PIT_PCSR_PRE( 0x9 ) | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_OVW; /* Initialize the periodic timer interrupt. */ MCF_PIT_PMR0 = MCF_PIT_MODULUS_REGISTER( configTICK_RATE_HZ ); /* Configure interrupt priority and level and unmask interrupt. */ MCF_INTC0_ICR36 = MCF_INTC0_ICRn_IL( 0x1 ) | MCF_INTC0_ICRn_IP( 0x1 ); MCF_INTC0_IMRH &= ~( MCF_INTC0_IMRH_INT_MASK36 | MCF_INTC0_IMRH_MASKALL ); /* Enable interrupts */ MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_EN | MCF_PIT_PCSR_PIF; } /* Restore the context of the first task that is going to run. */ portRESTORE_CONTEXT( ); /* Should not get here. */ return pdTRUE; } void vPortEndScheduler( void ) { }