1 /*
2  * Copyright (c) 2006-2021, RT-Thread Development Team
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  *
6  * Change Logs:
7  * Date           Author       Notes
8  * 2011-09-23     Bernard      the first version
9  * 2011-10-05     Bernard      add thumb mode
10  */
11 #include <rtthread.h>
12 #include <cpuport.h>
13 #include <board.h>
14 
15 /**
16  * @addtogroup ARM Cortex-A
17  */
18 /*@{*/
19 
20 /**
21  * This function will initialize thread stack
22  *
23  * @param tentry the entry of thread
24  * @param parameter the parameter of entry
25  * @param stack_addr the beginning stack address
26  * @param texit the function will be called when thread exit
27  *
28  * @return stack address
29  */
rt_hw_stack_init(void * tentry,void * parameter,rt_uint8_t * stack_addr,void * texit)30 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
31                              rt_uint8_t *stack_addr, void *texit)
32 {
33     rt_uint32_t *stk;
34 
35     stack_addr += sizeof(rt_uint32_t);
36     stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
37     stk      = (rt_uint32_t *)stack_addr;
38     *(--stk) = (rt_uint32_t)_thread_start;  /* entry point */
39     *(--stk) = (rt_uint32_t)texit;          /* lr */
40     *(--stk) = 0xdeadbeef;                  /* r12 */
41     *(--stk) = 0xdeadbeef;                  /* r11 */
42     *(--stk) = 0xdeadbeef;                  /* r10 */
43     *(--stk) = 0xdeadbeef;                  /* r9 */
44     *(--stk) = 0xdeadbeef;                  /* r8 */
45     *(--stk) = 0xdeadbeef;                  /* r7 */
46     *(--stk) = 0xdeadbeef;                  /* r6 */
47     *(--stk) = 0xdeadbeef;                  /* r5 */
48     *(--stk) = 0xdeadbeef;                  /* r4 */
49     *(--stk) = 0xdeadbeef;                  /* r3 */
50     *(--stk) = 0xdeadbeef;                  /* r2 */
51     *(--stk) = (rt_uint32_t)tentry;         /* r1 : argument 2 for trampoline */
52     *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument 1 */
53     /* cpsr */
54     if ((rt_uint32_t)tentry & 0x01)
55         *(--stk) = SVCMODE | 0x20;          /* thumb mode */
56     else
57         *(--stk) = SVCMODE;                 /* arm mode   */
58 
59 #ifdef RT_USING_SMART
60     *(--stk) = 0;       /* user lr */
61     *(--stk) = 0;       /* user sp*/
62 #endif
63 #ifdef RT_USING_FPU
64     *(--stk) = 0;       /* not use fpu*/
65 #endif
66 
67     /* return task's current stack address */
68     return (rt_uint8_t *)stk;
69 }
70 
71 /*@}*/
72