cpu_task.h

uT Kernel os source code for AT91

/*
 *----------------------------------------------------------------------
 *    micro T-Kernel
 *
 *    Copyright (C) 2006-2007 by Ken Sakamura. All rights reserved.
 *    micro T-Kernel is distributed under the micro T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2007/03/26.
 *
 *----------------------------------------------------------------------
 */

/*
 *	cpu_task.h (AT91)
 *	CPU-Dependent Task Start Processing
 */

#ifndef _CPU_TASK_
#define _CPU_TASK_

#include "cpu_insn.h"

/*
 * System stack configuration at task startup
 */
typedef struct {
	VW	r[12];		/* R0-R11 */
	UW	taskmode;
	VP	usp;		/* R13_usr */
	VP	lr_usr;		/* R14_usr */
	VP	lr_svc;		/* R14_svc */
	VW	spsr_svc;
	VW	ip;		/* R12 */
	VP	pc;		/* R15 */
} SStackFrame;

/*
 * Size of system stack area destroyed by 'make_dormant()'
 * In other words, the size of area required to write by 'setup_context().'
 */
#define DORMANT_STACK_SIZE	( sizeof(VW) * 7 )	/* To 'taskmode' position */


/*
 * Create stack frame for task startup
 *	Call from 'make_dormant()'
 */
Inline void knl_setup_context( TCB *tcb )
{
	SStackFrame	*ssp;
	UW		pc, spsr;

	ssp = tcb->isstack;
	ssp--;

	spsr = PSR_SVC;
	pc = (UW)tcb->task;
	if ( (pc & 1) != 0 ) {
		spsr |= PSR_T;		/* Thumb mode */
	}

	/* CPU context initialization */
	ssp->taskmode = 0;	/* Initial taskmode */
	ssp->spsr_svc = spsr;		/* Initial SR */
	ssp->pc = (VP)(pc & ~0x00000001UL);	/* Task startup address */
	tcb->tskctxb.ssp = ssp;		/* System stack */
}

/*
 * Set task startup code
 *	Called by 'tk_sta_tsk()' processing.
 */
Inline void knl_setup_stacd( TCB *tcb, INT stacd )
{
	SStackFrame	*ssp = tcb->tskctxb.ssp;

	ssp->r[0] = stacd;
	ssp->r[1] = (VW)tcb->exinf;
}

/*
 * Delete task contexts
 */
Inline void knl_cleanup_context( TCB *tcb )
{
}

#endif /* _CPU_TASK_ */