xref: /nrf52832-nimble/rt-thread/libcpu/arm/s3c44b0/stack.c (revision 042d53a763ad75cb1465103098bb88c245d95138)
1 /*
2  * Copyright (c) 2006-2018, RT-Thread Development Team
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  *
6  * Change Logs:
7  * Date           Author       Notes
8  * 2006-09-06     XuXinming    first version
9  */
10 #include <rtthread.h>
11 #include "s3c44b0.h"
12 
13 /**
14  * @addtogroup S3C44B0
15  */
16 /*@{*/
17 
18 /**
19  * This function will initialize thread stack
20  *
21  * @param tentry the entry of thread
22  * @param parameter the parameter of entry
23  * @param stack_addr the beginning stack address
24  * @param texit the function will be called when thread exit
25  *
26  * @return stack address
27  */
28 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
29                              rt_uint8_t *stack_addr, void *texit)
30 {
31     rt_uint32_t *stk;
32 
33     stack_addr += sizeof(rt_uint32_t);
34     stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
35     stk      = (rt_uint32_t *)stack_addr;
36     *(--stk) = (rt_uint32_t)tentry;         /* entry point */
37     *(--stk) = (rt_uint32_t)texit;          /* lr */
38     *(--stk) = 0xdeadbeef;                  /* r12 */
39     *(--stk) = 0xdeadbeef;                  /* r11 */
40     *(--stk) = 0xdeadbeef;                  /* r10 */
41     *(--stk) = 0xdeadbeef;                  /* r9 */
42     *(--stk) = 0xdeadbeef;                  /* r8 */
43     *(--stk) = 0xdeadbeef;                  /* r7 */
44     *(--stk) = 0xdeadbeef;                  /* r6 */
45     *(--stk) = 0xdeadbeef;                  /* r5 */
46     *(--stk) = 0xdeadbeef;                  /* r4 */
47     *(--stk) = 0xdeadbeef;                  /* r3 */
48     *(--stk) = 0xdeadbeef;                  /* r2 */
49     *(--stk) = 0xdeadbeef;                  /* r1 */
50     *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
51     *(--stk) = SVCMODE;                     /* cpsr */
52     *(--stk) = SVCMODE;                     /* spsr */
53 
54     /* return task's current stack address */
55     return (rt_uint8_t *)stk;
56 }
57 
58 /*@}*/
59