rt-thread-official/libcpu/nios/nios_ii/stack.c

/*
 * File      : stack.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006-2011, 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://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2011-02-14     aozima       first implementation for Nios II.
 */

#include <rtthread.h>

/**
 * @addtogroup NIOS_II
 */
/*@{*/

/**
 * 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)   = 0x01;                        /* status  */
	*(--stk) = (unsigned long)texit;        /* ra  */
	*(--stk) = 0xdeadbeef;                  /* fp  */
	*(--stk) = 0xdeadbeef;                  /* r23 */
	*(--stk) = 0xdeadbeef;                  /* r22 */
	*(--stk) = 0xdeadbeef;                  /* r21 */
	*(--stk) = 0xdeadbeef;                  /* r20 */
	*(--stk) = 0xdeadbeef;                  /* r19 */
	*(--stk) = 0xdeadbeef;                  /* r18 */
	*(--stk) = 0xdeadbeef;                  /* r17 */
	*(--stk) = 0xdeadbeef;                  /* r16 */
//	*(--stk) = 0xdeadbeef;                  /* r15 */
//	*(--stk) = 0xdeadbeef;                  /* r14 */
//	*(--stk) = 0xdeadbeef;                  /* r13 */
//	*(--stk) = 0xdeadbeef;                  /* r12 */
//	*(--stk) = 0xdeadbeef;                  /* r11 */
//	*(--stk) = 0xdeadbeef;                  /* r10 */
//	*(--stk) = 0xdeadbeef;                  /* r9  */
//	*(--stk) = 0xdeadbeef;                  /* r8  */
	*(--stk) = 0xdeadbeef;                  /* r7  */
	*(--stk) = 0xdeadbeef;                  /* r6  */
	*(--stk) = 0xdeadbeef;                  /* r5  */
	*(--stk) = (unsigned long)parameter;    /* r4 argument */
	*(--stk) = 0xdeadbeef;                  /* r3  */
	*(--stk) = 0xdeadbeef;                  /* r2  */
	*(--stk) = (unsigned long)tentry;       /* pc  */

//	*(stk)   = (unsigned long)tentry;		/* thread entry (ra) */
//	*(--stk) = (unsigned long)parameter;	/* thread argument, r4 */

	/* return task's current stack address */
	return (rt_uint8_t *)stk;
}

/*@}*/