os_cpu_c.c

uCOS-II ports on Tensilica HiFi330 core.

/********************************************************************************************************
 *                                               uC/OS-II
 *                                         The Real-Time Kernel
 *
 *                        (c) Copyright 1992-1998, Jean J. Labrosse, Plantation, FL
 *                                          All Rights Reserved
 *
 *
 *                                           Xtensa T1040
 *
 * File : OS_CPU_C.C
 * By   : Paul Subramanian
 *********************************************************************************************************/

#define  OS_CPU_GLOBALS
#include <xtensa/config/specreg.h>
#include <xtensa/config/core.h>
#include <xtensa/simcall.h>
#include "os_cpu.h"
#include "os_cfg.h"
#include "ucos_ii.h"
#include "includes.h"
#include "timer.h"
#include "interrupts.h"

extern OS_STK *newUserStackPtr;
extern OS_STK *userStackPtr; 


/*********************************************************************************************************
 *                                PERFORM A CONTEXT SWITCH (From interrupt level)
 *                                           void OSIntCtxSw(void)
 *
 **********************************************************************************************************/

void OSIntCtxSw(void)
{
  /* done as part of the user exception vector handler */
   OSTCBCur->OSTCBStkPtr = userStackPtr;
	OSTaskSwHook();
	OSTCBCur = OSTCBHighRdy;
	OSPrioCur = OSPrioHighRdy;
	newUserStackPtr = OSTCBHighRdy->OSTCBStkPtr;	
}

/*********************************************************************************************************/




void OSCtxSwIntsEnable(void)
{
	set_ccompare0( read_ccount() + TIMER0_INTERVAL ); //Level 1 timer interrupt
	enable_ints(SOFTWARE0_INT_MASK|TIMER0_INT_MASK);
}




/*********************************************************************************************************
 *                            Initialize Stack for the Task
 *
 **********************************************************************************************************/
OS_STK *OSTaskStkInit(void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt)
{
/* This function performs these functions
 * 1. Computation of the Initial Stack
 * 2. Initialization of the Stack
 */
 
	OS_STK *sp1;
	INT32U i;
	
	opt = opt;
	
	sp1 = (OS_STK *)((INT32U)ptos & 0xfffffff0);
	sp1 = sp1 - FRAME_SIZE / 4;
	
	for( i = 0 ; i < FRAME_SIZE / 4; i++ )
		sp1[i] = 0 ;
	
	sp1[ FRAME_PC/4 ] = (INT32U)task;
	sp1[ FRAME_PS/4 ] = XCHAL_PS_WOE_MASK | XCHAL_PS_UM_MASK | XCHAL_PS_EXCM_MASK | 
	(1 << XCHAL_PS_CALLINC_SHIFT);
	sp1[ FRAME_AR(6)/4 ] = (INT32U)pdata;
	sp1[ FRAME_AR(1)/4 ] = (INT32U)(sp1 + FRAME_SIZE / 4);
	return(sp1);
	 
}
/*********************************************************************************************************/










#if OS_CPU_HOOKS_EN
/*********************************************************************************************************
 *                                          TASK CREATION HOOK
 *
 * Description: This function is called when a task is created.
 *
 * Arguments  : ptcb   is a pointer to the task control block of the task being created.
 *
 * Note(s)    : 1) Interrupts are disabled during this call.
 *********************************************************************************************************/
void OSTaskCreateHook (OS_TCB *ptcb)
{
  ptcb = ptcb;                       /* Prevent compiler warning                                     */
}
/*********************************************************************************************************/






/*********************************************************************************************************
 *                                           TASK DELETION HOOK
 *
 * Description: This function is called when a task is deleted.
 *
 * Arguments  : ptcb   is a pointer to the task control block of the task being deleted.
 *
 * Note(s)    : 1) Interrupts are disabled during this call.
 *********************************************************************************************************/
void OSTaskDelHook (OS_TCB *ptcb)
{
  ptcb = ptcb;                       /* Prevent compiler warning                                     */
}
/*********************************************************************************************************/






/*********************************************************************************************************
 *                                           TASK SWITCH HOOK
 *
 * Description: This function is called when a task switch is performed.  This allows you to perform other
 *              operations during a context switch.
 *
 * Arguments  : none
 *
 * Note(s)    : 1) Interrupts are disabled during this call.
 *              2) It is assumed that the global pointer 'OSTCBHighRdy' points to the TCB of the task that
 *                 will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCur' points to the 
 *                 task being switched out (i.e. the preempted task).
 *********************************************************************************************************/
void OSTaskSwHook (void)
{
}
/*********************************************************************************************************/






/*********************************************************************************************************
 *                                           STATISTIC TASK HOOK
 *
 * Description: This function is called every second by uC/OS-II's statistics task.  This allows your 
 *              application to add functionality to the statistics task.
 *
 * Arguments  : none
 *********************************************************************************************************/
void OSTaskStatHook (void)
{
}
/*********************************************************************************************************/






/*********************************************************************************************************
 *                                               TICK HOOK
 *
 * Description: This function is called every tick.
 *
 * Arguments  : none
 *
 * Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
 *********************************************************************************************************/
void OSTimeTickHook (void)
{
}
/*********************************************************************************************************/






/*********************************************************************************************************
 *                                               OS Task Idle HOOK
 *
 * Description: This function is called by OS.
 *
 * Arguments  : none
 *
 * Note(s)    : 1) Interrupts may or may not be ENABLED during this call.
 *********************************************************************************************************/
void OSTaskIdleHook (void)
{
	/* WAITI instruction saves power by setting the current interrupt
	 * level, powering down the processor's logic and waiting for an
	 * interrupt
	 */
	asm("waiti 0");
}
/*********************************************************************************************************/


#endif // #if OS_CPU_HOOKS_EN