1 /*
2 * File : cpuport.c
3 * This file is part of RT-Thread RTOS
4 * COPYRIGHT (C) 2009 - 2011, RT-Thread Development Team
5 *
6 * The license and distribution terms for this file may be
7 * found in the file LICENSE in this distribution or at
8 * http://www.rt-thread.org/license/LICENSE
9 *
10 * Change Logs:
11 * Date Author Notes
12 * 20011-05-23 aozima the first version for PIC32.
13 * 20011-09-05 aozima merge all of C source code into cpuport.c.
14 */
15 #include <rtthread.h>
16
17 /**
18 * @addtogroup PIC32
19 */
20 /*@{*/
21
22 /* exception and interrupt handler table */
23 rt_uint32_t rt_interrupt_from_thread, rt_interrupt_to_thread;
24 rt_uint32_t rt_thread_switch_interrupt_flag;
25
_get_gp(void)26 rt_uint32_t __attribute__((nomips16)) _get_gp(void)
27 {
28 rt_uint32_t result;
29
30 // get the gp reg
31 asm volatile("move %0, $28" : "=r"(result));
32
33 return result;
34 }
35
36 /**
37 * This function will initialize thread stack
38 *
39 * @param tentry the entry of thread
40 * @param parameter the parameter of entry
41 * @param stack_addr the beginning stack address
42 * @param texit the function will be called when thread exit
43 *
44 * @return stack address
45 */
rt_hw_stack_init(void * tentry,void * parameter,rt_uint8_t * stack_addr,void * texit)46 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter, rt_uint8_t *stack_addr, void *texit)
47 {
48 rt_uint32_t *stk;
49
50 /** Start at stack top */
51 stk = (rt_uint32_t *)stack_addr;
52 *(stk) = (rt_uint32_t) tentry; /* pc: Entry Point */
53 *(--stk) = (rt_uint32_t) 0x00800000; /* c0_cause: IV=1, */
54 *(--stk) = (rt_uint32_t) 0; /* c0_badvaddr */
55 *(--stk) = (rt_uint32_t) 0; /* lo */
56 *(--stk) = (rt_uint32_t) 0; /* hi */
57 *(--stk) = (rt_uint32_t) 1; /* C0_SR: IE = En, */
58 *(--stk) = (rt_uint32_t) texit; /* 31 ra */
59 *(--stk) = (rt_uint32_t) 0x0000001e; /* 30 s8 */
60 *(--stk) = (rt_uint32_t) stack_addr; /* 29 sp */
61 *(--stk) = (rt_uint32_t) _get_gp(); /* 28 gp */
62 *(--stk) = (rt_uint32_t) 0x0000001b; /* 27 k1 */
63 *(--stk) = (rt_uint32_t) 0x0000001a; /* 26 k0 */
64 *(--stk) = (rt_uint32_t) 0x00000019; /* 25 t9 */
65 *(--stk) = (rt_uint32_t) 0x00000018; /* 24 t8 */
66 *(--stk) = (rt_uint32_t) 0x00000017; /* 23 s7 */
67 *(--stk) = (rt_uint32_t) 0x00000016; /* 22 s6 */
68 *(--stk) = (rt_uint32_t) 0x00000015; /* 21 s5 */
69 *(--stk) = (rt_uint32_t) 0x00000014; /* 20 s4 */
70 *(--stk) = (rt_uint32_t) 0x00000013; /* 19 s3 */
71 *(--stk) = (rt_uint32_t) 0x00000012; /* 18 s2 */
72 *(--stk) = (rt_uint32_t) 0x00000011; /* 17 s1 */
73 *(--stk) = (rt_uint32_t) 0x00000010; /* 16 s0 */
74 *(--stk) = (rt_uint32_t) 0x0000000f; /* 15 t7 */
75 *(--stk) = (rt_uint32_t) 0x0000000e; /* 14 t6 */
76 *(--stk) = (rt_uint32_t) 0x0000000d; /* 13 t5 */
77 *(--stk) = (rt_uint32_t) 0x0000000c; /* 12 t4 */
78 *(--stk) = (rt_uint32_t) 0x0000000b; /* 11 t3 */
79 *(--stk) = (rt_uint32_t) 0x0000000a; /* 10 t2 */
80 *(--stk) = (rt_uint32_t) 0x00000009; /* 9 t1 */
81 *(--stk) = (rt_uint32_t) 0x00000008; /* 8 t0 */
82 *(--stk) = (rt_uint32_t) 0x00000007; /* 7 a3 */
83 *(--stk) = (rt_uint32_t) 0x00000006; /* 6 a2 */
84 *(--stk) = (rt_uint32_t) 0x00000005; /* 5 a1 */
85 *(--stk) = (rt_uint32_t) parameter; /* 4 a0 */
86 *(--stk) = (rt_uint32_t) 0x00000003; /* 3 v1 */
87 *(--stk) = (rt_uint32_t) 0x00000002; /* 2 v0 */
88 *(--stk) = (rt_uint32_t) 0x00000001; /* 1 at */
89 *(--stk) = (rt_uint32_t) 0x00000000; /* 0 zero */
90
91 /* return task's current stack address */
92 return (rt_uint8_t *)stk;
93 }
94
95
96 /*@}*/
97