/*
 * File      : stack.c
 * COPYRIGHT (C) 2008 - 2016, RT-Thread Development Team
 *
 *  This program 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.
 *
 *  This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-05-17     swkyer       first version
 * 2010-07-07     Bernard      porting to Ingenic CPU
 */
#include <rtthread.h>

/**
 * @addtogroup Ingenic
 */
/*@{*/

extern rt_uint32_t cp0_get_cause(void);
extern rt_uint32_t cp0_get_status(void);
extern rt_uint32_t cp0_get_hi(void);
extern rt_uint32_t cp0_get_lo(void);

/**
 * 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)
{
    rt_uint32_t *stk;
    static rt_uint32_t g_sr = 0;

    if (g_sr == 0)
    {
        g_sr = cp0_get_status();
        g_sr &= 0xfffffffe;
        g_sr |= 0x0403;
    }

    /** Start at stack top */
    stk = (rt_uint32_t *)stack_addr;
    *(stk)   = (rt_uint32_t) tentry;        /* pc: Entry Point */
    *(--stk) = (rt_uint32_t) 0xeeee;        /* c0_cause */
    *(--stk) = (rt_uint32_t) 0xffff;        /* c0_badvaddr */
    *(--stk) = (rt_uint32_t) cp0_get_lo();  /* lo */
    *(--stk) = (rt_uint32_t) cp0_get_hi();  /* hi */
    *(--stk) = (rt_uint32_t) g_sr;          /* C0_SR: HW2 = En, IE = En */
    *(--stk) = (rt_uint32_t) texit;         /* ra */
    *(--stk) = (rt_uint32_t) 0x0000001e;    /* s8 */
    *(--stk) = (rt_uint32_t) stack_addr;    /* sp */
    *(--stk) = (rt_uint32_t) 0x0000001c;    /* gp */
    *(--stk) = (rt_uint32_t) 0x0000001b;    /* k1 */
    *(--stk) = (rt_uint32_t) 0x0000001a;    /* k0 */
    *(--stk) = (rt_uint32_t) 0x00000019;    /* t9 */
    *(--stk) = (rt_uint32_t) 0x00000018;    /* t8 */
    *(--stk) = (rt_uint32_t) 0x00000017;    /* s7 */
    *(--stk) = (rt_uint32_t) 0x00000016;    /* s6 */
    *(--stk) = (rt_uint32_t) 0x00000015;    /* s5 */
    *(--stk) = (rt_uint32_t) 0x00000014;    /* s4 */
    *(--stk) = (rt_uint32_t) 0x00000013;    /* s3 */
    *(--stk) = (rt_uint32_t) 0x00000012;    /* s2 */
    *(--stk) = (rt_uint32_t) 0x00000011;    /* s1 */
    *(--stk) = (rt_uint32_t) 0x00000010;    /* s0 */
    *(--stk) = (rt_uint32_t) 0x0000000f;    /* t7 */
    *(--stk) = (rt_uint32_t) 0x0000000e;    /* t6 */
    *(--stk) = (rt_uint32_t) 0x0000000d;    /* t5 */
    *(--stk) = (rt_uint32_t) 0x0000000c;    /* t4 */
    *(--stk) = (rt_uint32_t) 0x0000000b;    /* t3 */
    *(--stk) = (rt_uint32_t) 0x0000000a;    /* t2 */
    *(--stk) = (rt_uint32_t) 0x00000009;    /* t1 */
    *(--stk) = (rt_uint32_t) 0x00000008;    /* t0 */
    *(--stk) = (rt_uint32_t) 0x00000007;    /* a3 */
    *(--stk) = (rt_uint32_t) 0x00000006;    /* a2 */
    *(--stk) = (rt_uint32_t) 0x00000005;    /* a1 */
    *(--stk) = (rt_uint32_t) parameter;     /* a0 */
    *(--stk) = (rt_uint32_t) 0x00000003;    /* v1 */
    *(--stk) = (rt_uint32_t) 0x00000002;    /* v0 */
    *(--stk) = (rt_uint32_t) 0x00000001;    /* at */
    *(--stk) = (rt_uint32_t) 0x00000000;    /* zero */

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

/*@}*/