summaryrefslogtreecommitdiffstats
path: root/arch/ppc64/xmon/start.c
blob: a9265bcc79b24d1e3750efdb3ec86e7ee3d1cd61 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*
 * Copyright (C) 1996 Paul Mackerras.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
#include <linux/config.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sysrq.h>
#include <linux/init.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/processor.h>
#include <asm/udbg.h>
#include <asm/system.h>
#include "nonstdio.h"

#ifdef CONFIG_MAGIC_SYSRQ

static void sysrq_handle_xmon(int key, struct pt_regs *pt_regs,
			      struct tty_struct *tty) 
{
	/* ensure xmon is enabled */
	xmon_init();
	debugger(pt_regs);
}

static struct sysrq_key_op sysrq_xmon_op = 
{
	.handler =	sysrq_handle_xmon,
	.help_msg =	"Xmon",
	.action_msg =	"Entering xmon",
};

static int __init setup_xmon_sysrq(void)
{
	register_sysrq_key('x', &sysrq_xmon_op);
	return 0;
}
__initcall(setup_xmon_sysrq);
#endif /* CONFIG_MAGIC_SYSRQ */

int
xmon_write(void *handle, void *ptr, int nb)
{
	return udbg_write(ptr, nb);
}

int
xmon_read(void *handle, void *ptr, int nb)
{
	return udbg_read(ptr, nb);
}

int
xmon_read_poll(void)
{
	return udbg_getc_poll();
}
 
FILE *xmon_stdin;
FILE *xmon_stdout;

int
xmon_putc(int c, void *f)
{
	char ch = c;

	if (c == '\n')
		xmon_putc('\r', f);
	return xmon_write(f, &ch, 1) == 1? c: -1;
}

int
xmon_putchar(int c)
{
	return xmon_putc(c, xmon_stdout);
}

int
xmon_fputs(char *str, void *f)
{
	int n = strlen(str);

	return xmon_write(f, str, n) == n? 0: -1;
}

int
xmon_readchar(void)
{
	char ch;

	for (;;) {
		switch (xmon_read(xmon_stdin, &ch, 1)) {
		case 1:
			return ch;
		case -1:
			xmon_printf("read(stdin) returned -1\r\n", 0, 0);
			return -1;
		}
	}
}

static char line[256];
static char *lineptr;
static int lineleft;

int
xmon_getchar(void)
{
	int c;

	if (lineleft == 0) {
		lineptr = line;
		for (;;) {
			c = xmon_readchar();
			if (c == -1 || c == 4)
				break;
			if (c == '\r' || c == '\n') {
				*lineptr++ = '\n';
				xmon_putchar('\n');
				break;
			}
			switch (c) {
			case 0177:
			case '\b':
				if (lineptr > line) {
					xmon_putchar('\b');
					xmon_putchar(' ');
					xmon_putchar('\b');
					--lineptr;
				}
				break;
			case 'U' & 0x1F:
				while (lineptr > line) {
					xmon_putchar('\b');
					xmon_putchar(' ');
					xmon_putchar('\b');
					--lineptr;
				}
				break;
			default:
				if (lineptr >= &line[sizeof(line) - 1])
					xmon_putchar('\a');
				else {
					xmon_putchar(c);
					*lineptr++ = c;
				}
			}
		}
		lineleft = lineptr - line;
		lineptr = line;
	}
	if (lineleft == 0)
		return -1;
	--lineleft;
	return *lineptr++;
}

char *
xmon_fgets(char *str, int nb, void *f)
{
	char *p;
	int c;

	for (p = str; p < str + nb - 1; ) {
		c = xmon_getchar();
		if (c == -1) {
			if (p == str)
				return NULL;
			break;
		}
		*p++ = c;
		if (c == '\n')
			break;
	}
	*p = 0;
	return str;
}