1 /*
2 * File : cpuport.c
3 * This file is part of RT-Thread RTOS
4 * COPYRIGHT (C) 2012, 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 * 2012-02-13 mojingxian first version
13 */
14
15 #include <rtthread.h>
16
17 /* flag in interrupt handling */
18 rt_uint32_t rt_interrupt_from_thread;
19 rt_uint32_t rt_interrupt_to_thread;
20 rt_uint32_t rt_thread_switch_interrupt_flag;
21
22 /**
23 * initializes stack of thread
24 */
rt_hw_stack_init(void * tentry,void * parameter,rt_uint8_t * stack_addr,void * texit)25 rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
26 rt_uint8_t *stack_addr, void *texit)
27 {
28 unsigned char i;
29 unsigned long *stk;
30
31 stk = (unsigned long *)stack_addr; /* Load stack pointer */
32
33 /* Simulate a function call to the task with an argument */
34 stk -= 3; /* 3 words assigned for incoming args (R0, R1, R2) */
35
36 /* Now simulating vectoring to an ISR */
37 *--stk = (unsigned long)parameter; /* R0 value - caller's incoming argument #1 */
38 *--stk = (unsigned long)0; /* P1 value - value irrelevant */
39
40 *--stk = (unsigned long)texit; /* RETS value - NO task should return with RTS. */
41 /* however OS_CPU_Invalid_Task_Return is a safety */
42 /* catch-allfor tasks that return with an RTS */
43
44 *--stk = (unsigned long)parameter; /* R1 value - caller's incoming argument #2 */
45 /* (not relevant in current test example) */
46 *--stk = (unsigned long)parameter; /* R2 value - caller's incoming argument #3 */
47 /* (not relevant in current test example) */
48 *--stk = (unsigned long)0; /* P0 value - value irrelevant */
49 *--stk = (unsigned long)0; /* P2 value - value irrelevant */
50 *--stk = (unsigned long)0; /* ASTAT value - caller's ASTAT value - value */
51 /* irrelevant */
52
53 *--stk = (unsigned long)tentry; /* RETI value- pushing the start address of the task */
54
55 for (i = 0; i < 35; i++) /* remaining reg values - R7:3, P5:3, */
56 { /* 4 words of A1:0(.W,.X), LT0, LT1, */
57 *--stk = (unsigned long)0; /* LC0, LC1, LB0, LB1,I3:0, M3:0, L3:0, B3:0, */
58 } /* All values irrelevant */
59
60 return (rt_uint8_t *)stk; /* Return top-of-stack */
61 }
62
rt_hw_context_switch(rt_uint32_t from,rt_uint32_t to)63 void rt_hw_context_switch(rt_uint32_t from, rt_uint32_t to)
64 {
65 if (rt_thread_switch_interrupt_flag != 1)
66 {
67 rt_thread_switch_interrupt_flag = 1;
68 rt_interrupt_from_thread = from;
69 }
70
71 rt_interrupt_to_thread = to;
72 asm("raise 14;"); // Raise Interrupt 14 (trap)
73 }
74
rt_hw_context_switch_interrupt(rt_uint32_t from,rt_uint32_t to)75 void rt_hw_context_switch_interrupt(rt_uint32_t from, rt_uint32_t to)
76 {
77 if (rt_thread_switch_interrupt_flag != 1)
78 {
79 rt_thread_switch_interrupt_flag = 1;
80 rt_interrupt_from_thread = from;
81 }
82
83 rt_interrupt_to_thread = to;
84 asm("raise 14;"); // Raise Interrupt 14 (trap)
85 }
86
rt_hw_context_switch_to(rt_uint32_t to)87 void rt_hw_context_switch_to(rt_uint32_t to)
88 {
89 rt_thread_switch_interrupt_flag = 1;
90 rt_interrupt_from_thread = 0;
91 rt_interrupt_to_thread = to;
92 asm("raise 14;"); // Raise Interrupt 14 (trap)
93 }
94