rt-thread/libcpu/xilinx/microblaze/stack.c

/*
 * File      : stack.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://openlab.rt-thread.com/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2011-12-17     nl1031       first implementation for MicroBlaze.
 *
 */
#include <rtthread.h>
extern   void  *_SDA_BASE_;
extern   void  *_SDA2_BASE_;



/**
 * This function will initialize thread stack
 *
 * @param tentry the entry of thread
 * @param parameter the parameter of entry
 * @param stack_addr the beginning stack address
 * @param texit the function will be called when thread exit
 *
 * @return stack address
 */
rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
	rt_uint8_t *stack_addr, void *texit)
{
	unsigned long *stk;

	stk 	 = (unsigned long *)stack_addr;
	stk--;
	stk--;
	*stk-- = 0;								/* r31 */
	*stk-- = 0;								/* r30 */
	*stk-- = 0;								/* r29 */
	*stk-- = 0;								/* r28 */
	*stk-- = 0;								/* r27 */
	*stk-- = 0;								/* r26 */
	*stk-- = 0;								/* r25 */
	*stk-- = 0;								/* r24 */
	*stk-- = 0;								/* r23 */
	*stk-- = 0;								/* r22 */
	*stk-- = 0;								/* r21 */
	*stk-- = 0;								/* r20 */
	*stk-- = 0;								/* r19 */
	*stk-- = 0;								/* r18 */
	*stk-- = 0;								/* r17 */
	*stk-- = (unsigned long)texit - 8;		/* r15 = task return address*/
	*stk-- = (unsigned long)tentry;		/* r14 = entry address*/
	*stk-- = (unsigned long)&_SDA_BASE_;	/* r13 */
	*stk-- = 0;								/* r12 */
	*stk-- = 0;								/* r11 */
	*stk-- = 0;								/* r10 */
	*stk-- = 0;								/* r09 */
	*stk-- = 0;								/* r08 */
	*stk-- = 0;								/* r07 */
	*stk-- = 0;								/* r06 */
	*stk-- = (unsigned long) parameter;	/* r05 */
	*stk-- = 0;								/* r04 */
	*stk-- = 0;								/* r03 */
	*stk-- = (unsigned long)&_SDA2_BASE_;	/* r02 */
	*stk   = 2;   							/* enable interrupt */
	return (rt_uint8_t *)stk;
}