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comparison src/arm.c @ 0:83c23a36980d

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Init
author Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp>
date Fri, 26 May 2017 23:11:05 +0900
parents
children d876c9a65239
comparison
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-1:000000000000 0:83c23a36980d
1 // BSP support routine
2 #include "types.h"
3 #include "defs.h"
4 #include "param.h"
5 #include "memlayout.h"
6 #include "proc.h"
7 #include "arm.h"
8 #include "mmu.h"
9
10 void cli (void)
11 {
12 uint val;
13
14 // ok, enable paging using read/modify/write
15 asm("MRS %[v], cpsr": [v]"=r" (val)::);
16 val |= DIS_INT;
17 asm("MSR cpsr_cxsf, %[v]": :[v]"r" (val):);
18 }
19
20 void sti (void)
21 {
22 uint val;
23
24 // ok, enable paging using read/modify/write
25 asm("MRS %[v], cpsr": [v]"=r" (val)::);
26 val &= ~DIS_INT;
27 asm("MSR cpsr_cxsf, %[v]": :[v]"r" (val):);
28 }
29
30 // return the cpsr used for user program
31 uint spsr_usr ()
32 {
33 uint val;
34
35 // ok, enable paging using read/modify/write
36 asm("MRS %[v], cpsr": [v]"=r" (val)::);
37 val &= ~MODE_MASK;
38 val |= USR_MODE;
39
40 return val;
41 }
42
43 // return whether interrupt is currently enabled
44 int int_enabled ()
45 {
46 uint val;
47
48 // ok, enable paging using read/modify/write
49 asm("MRS %[v], cpsr": [v]"=r" (val)::);
50
51 return !(val & DIS_INT);
52 }
53
54 // Pushcli/popcli are like cli/sti except that they are matched:
55 // it takes two popcli to undo two pushcli. Also, if interrupts
56 // are off, then pushcli, popcli leaves them off.
57
58 void pushcli (void)
59 {
60 int enabled;
61
62 enabled = int_enabled();
63
64 cli();
65
66 if (cpu->ncli++ == 0) {
67 cpu->intena = enabled;
68 }
69 }
70
71 void popcli (void)
72 {
73 if (int_enabled()) {
74 panic("popcli - interruptible");
75 }
76
77 if (--cpu->ncli < 0) {
78 cprintf("cpu (%d)->ncli: %d\n", cpu, cpu->ncli);
79 panic("popcli -- ncli < 0");
80 }
81
82 if ((cpu->ncli == 0) && cpu->intena) {
83 sti();
84 }
85 }
86
87 // Record the current call stack in pcs[] by following the call chain.
88 // In ARM ABI, the function prologue is as:
89 // push {fp, lr}
90 // add fp, sp, #4
91 // so, fp points to lr, the return address
92 void getcallerpcs (void * v, uint pcs[])
93 {
94 uint *fp;
95 int i;
96
97 fp = (uint*) v;
98
99 for (i = 0; i < N_CALLSTK; i++) {
100 if ((fp == 0) || (fp < (uint*) KERNBASE) || (fp == (uint*) 0xffffffff)) {
101 break;
102 }
103
104 fp = fp - 1; // points fp to the saved fp
105 pcs[i] = fp[1]; // saved lr
106 fp = (uint*) fp[0]; // saved fp
107 }
108
109 for (; i < N_CALLSTK; i++) {
110 pcs[i] = 0;
111 }
112 }
113
114 void show_callstk (char *s)
115 {
116 int i;
117 uint pcs[N_CALLSTK];
118
119 cprintf("%s\n", s);
120
121 getcallerpcs(get_fp(), pcs);
122
123 for (i = N_CALLSTK - 1; i >= 0; i--) {
124 cprintf("%d: 0x%x\n", i + 1, pcs[i]);
125 }
126
127 }