xref: /nrf52832-nimble/rt-thread/libcpu/arm/arm926/stack.c (revision 104654410c56c573564690304ae786df310c91fc)
1*10465441SEvalZero /*
2*10465441SEvalZero  * Copyright (c) 2006-2018, RT-Thread Development Team
3*10465441SEvalZero  *
4*10465441SEvalZero  * SPDX-License-Identifier: Apache-2.0
5*10465441SEvalZero  *
6*10465441SEvalZero  * Change Logs:
7*10465441SEvalZero  * Date           Author       Notes
8*10465441SEvalZero  * 2011-01-13     weety      copy from mini2440
9*10465441SEvalZero  */
10*10465441SEvalZero #include <rtthread.h>
11*10465441SEvalZero 
12*10465441SEvalZero /*****************************/
13*10465441SEvalZero /* CPU Mode                  */
14*10465441SEvalZero /*****************************/
15*10465441SEvalZero #define USERMODE        0x10
16*10465441SEvalZero #define FIQMODE         0x11
17*10465441SEvalZero #define IRQMODE         0x12
18*10465441SEvalZero #define SVCMODE         0x13
19*10465441SEvalZero #define ABORTMODE       0x17
20*10465441SEvalZero #define UNDEFMODE       0x1b
21*10465441SEvalZero #define MODEMASK        0x1f
22*10465441SEvalZero #define NOINT           0xc0
23*10465441SEvalZero 
24*10465441SEvalZero /**
25*10465441SEvalZero  * This function will initialize thread stack
26*10465441SEvalZero  *
27*10465441SEvalZero  * @param tentry the entry of thread
28*10465441SEvalZero  * @param parameter the parameter of entry
29*10465441SEvalZero  * @param stack_addr the beginning stack address
30*10465441SEvalZero  * @param texit the function will be called when thread exit
31*10465441SEvalZero  *
32*10465441SEvalZero  * @return stack address
33*10465441SEvalZero  */
rt_hw_stack_init(void * tentry,void * parameter,rt_uint8_t * stack_addr,void * texit)34*10465441SEvalZero rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
35*10465441SEvalZero                              rt_uint8_t *stack_addr, void *texit)
36*10465441SEvalZero {
37*10465441SEvalZero     rt_uint32_t *stk;
38*10465441SEvalZero 
39*10465441SEvalZero     stack_addr += sizeof(rt_uint32_t);
40*10465441SEvalZero     stack_addr  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
41*10465441SEvalZero     stk      = (rt_uint32_t *)stack_addr;
42*10465441SEvalZero 
43*10465441SEvalZero     *(--stk) = (rt_uint32_t)tentry;         /* entry point */
44*10465441SEvalZero     *(--stk) = (rt_uint32_t)texit;          /* lr */
45*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r12 */
46*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r11 */
47*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r10 */
48*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r9 */
49*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r8 */
50*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r7 */
51*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r6 */
52*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r5 */
53*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r4 */
54*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r3 */
55*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r2 */
56*10465441SEvalZero     *(--stk) = 0xdeadbeef;                  /* r1 */
57*10465441SEvalZero     *(--stk) = (rt_uint32_t)parameter;      /* r0 : argument */
58*10465441SEvalZero     /* cpsr */
59*10465441SEvalZero     if ((rt_uint32_t)tentry & 0x01)
60*10465441SEvalZero         *(--stk) = SVCMODE | 0x20;          /* thumb mode */
61*10465441SEvalZero     else
62*10465441SEvalZero         *(--stk) = SVCMODE;                 /* arm mode   */
63*10465441SEvalZero 
64*10465441SEvalZero     /* return task's current stack address */
65*10465441SEvalZero     return (rt_uint8_t *)stk;
66*10465441SEvalZero }
67