xref: /nrf52832-nimble/rt-thread/libcpu/risc-v/common/cpuport.c (revision 104654410c56c573564690304ae786df310c91fc)
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  * 2018/10/28     Bernard      The unify RISC-V porting code.
9  */
10 
11 #include <rthw.h>
12 #include <rtthread.h>
13 
14 #include "cpuport.h"
15 
16 #ifndef RT_USING_SMP
17 volatile rt_ubase_t  rt_interrupt_from_thread = 0;
18 volatile rt_ubase_t  rt_interrupt_to_thread   = 0;
19 volatile rt_uint32_t rt_thread_switch_interrupt_flag = 0;
20 #endif
21 
22 struct rt_hw_stack_frame
23 {
24     rt_ubase_t epc;        /* epc - epc    - program counter                     */
25     rt_ubase_t ra;         /* x1  - ra     - return address for jumps            */
26     rt_ubase_t mstatus;    /*              - machine status register             */
27     rt_ubase_t gp;         /* x3  - gp     - global pointer                      */
28     rt_ubase_t tp;         /* x4  - tp     - thread pointer                      */
29     rt_ubase_t t0;         /* x5  - t0     - temporary register 0                */
30     rt_ubase_t t1;         /* x6  - t1     - temporary register 1                */
31     rt_ubase_t t2;         /* x7  - t2     - temporary register 2                */
32     rt_ubase_t s0_fp;      /* x8  - s0/fp  - saved register 0 or frame pointer   */
33     rt_ubase_t s1;         /* x9  - s1     - saved register 1                    */
34     rt_ubase_t a0;         /* x10 - a0     - return value or function argument 0 */
35     rt_ubase_t a1;         /* x11 - a1     - return value or function argument 1 */
36     rt_ubase_t a2;         /* x12 - a2     - function argument 2                 */
37     rt_ubase_t a3;         /* x13 - a3     - function argument 3                 */
38     rt_ubase_t a4;         /* x14 - a4     - function argument 4                 */
39     rt_ubase_t a5;         /* x15 - a5     - function argument 5                 */
40     rt_ubase_t a6;         /* x16 - a6     - function argument 6                 */
41     rt_ubase_t a7;         /* x17 - s7     - function argument 7                 */
42     rt_ubase_t s2;         /* x18 - s2     - saved register 2                    */
43     rt_ubase_t s3;         /* x19 - s3     - saved register 3                    */
44     rt_ubase_t s4;         /* x20 - s4     - saved register 4                    */
45     rt_ubase_t s5;         /* x21 - s5     - saved register 5                    */
46     rt_ubase_t s6;         /* x22 - s6     - saved register 6                    */
47     rt_ubase_t s7;         /* x23 - s7     - saved register 7                    */
48     rt_ubase_t s8;         /* x24 - s8     - saved register 8                    */
49     rt_ubase_t s9;         /* x25 - s9     - saved register 9                    */
50     rt_ubase_t s10;        /* x26 - s10    - saved register 10                   */
51     rt_ubase_t s11;        /* x27 - s11    - saved register 11                   */
52     rt_ubase_t t3;         /* x28 - t3     - temporary register 3                */
53     rt_ubase_t t4;         /* x29 - t4     - temporary register 4                */
54     rt_ubase_t t5;         /* x30 - t5     - temporary register 5                */
55     rt_ubase_t t6;         /* x31 - t6     - temporary register 6                */
56 };
57 
58 /**
59  * This function will initialize thread stack
60  *
61  * @param tentry the entry of thread
62  * @param parameter the parameter of entry
63  * @param stack_addr the beginning stack address
64  * @param texit the function will be called when thread exit
65  *
66  * @return stack address
67  */
rt_hw_stack_init(void * tentry,void * parameter,rt_uint8_t * stack_addr,void * texit)68 rt_uint8_t *rt_hw_stack_init(void       *tentry,
69                              void       *parameter,
70                              rt_uint8_t *stack_addr,
71                              void       *texit)
72 {
73     struct rt_hw_stack_frame *frame;
74     rt_uint8_t         *stk;
75     int                i;
76 
77     stk  = stack_addr + sizeof(rt_ubase_t);
78     stk  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_ubase_t)stk, REGBYTES);
79     stk -= sizeof(struct rt_hw_stack_frame);
80 
81     frame = (struct rt_hw_stack_frame *)stk;
82 
83     for (i = 0; i < sizeof(struct rt_hw_stack_frame) / sizeof(rt_ubase_t); i++)
84     {
85         ((rt_ubase_t *)frame)[i] = 0xdeadbeef;
86     }
87 
88     frame->ra      = (rt_ubase_t)texit;
89     frame->a0      = (rt_ubase_t)parameter;
90     frame->epc     = (rt_ubase_t)tentry;
91 
92     /* force to machine mode(MPP=11) and set MPIE to 1 */
93     frame->mstatus = 0x00007880;
94 
95     return stk;
96 }
97 
98 /*
99  * #ifdef RT_USING_SMP
100  * void rt_hw_context_switch_interrupt(void *context, rt_ubase_t from, rt_ubase_t to, struct rt_thread *to_thread);
101  * #else
102  * void rt_hw_context_switch_interrupt(rt_ubase_t from, rt_ubase_t to);
103  * #endif
104  */
105 #ifndef RT_USING_SMP
rt_hw_context_switch_interrupt(rt_ubase_t from,rt_ubase_t to)106 void rt_hw_context_switch_interrupt(rt_ubase_t from, rt_ubase_t to)
107 {
108     if (rt_thread_switch_interrupt_flag == 0)
109         rt_interrupt_from_thread = from;
110 
111     rt_interrupt_to_thread = to;
112     rt_thread_switch_interrupt_flag = 1;
113 
114     return ;
115 }
116 #endif /* end of RT_USING_SMP */
117 
118 /** shutdown CPU */
rt_hw_cpu_shutdown()119 void rt_hw_cpu_shutdown()
120 {
121     rt_uint32_t level;
122     rt_kprintf("shutdown...\n");
123 
124     level = rt_hw_interrupt_disable();
125     while (level)
126     {
127         RT_ASSERT(0);
128     }
129 }
130