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
|
/*-
* Copyright (c) 2006 Sam Leffler
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Support for redirecting console msgs to gdb. We register
* a pseudo console to hook cnputc and send stuff to the gdb
* port. The only trickiness here is buffering output so this
* isn't dog slow.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cons.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <machine/gdb_machdep.h>
#include <machine/kdb.h>
#include <gdb/gdb.h>
#include <gdb/gdb_int.h>
struct gdbcons {
int npending;
/* /2 for hex conversion, -6 for protocol glue */
char buf[GDB_BUFSZ/2 - 6];
struct callout flush;
};
static struct gdbcons state = { -1 };
static int gdbcons_enable = 0;
SYSCTL_INT(_debug, OID_AUTO, gdbcons, CTLFLAG_RW, &gdbcons_enable,
0, "copy console messages to gdb");
TUNABLE_INT("debug.gdbcons", &gdbcons_enable);
static void
gdb_cnprobe(struct consdev *cp)
{
sprintf(cp->cn_name, "gdb");
cp->cn_pri = CN_LOW; /* XXX no way to say "write only" */
}
static void
gdb_cninit(struct consdev *cp)
{
struct gdbcons *c = &state;
/* setup tx buffer and callout */
if (c->npending == -1) {
c->npending = 0;
callout_init(&c->flush, CALLOUT_MPSAFE);
cp->cn_arg = c;
}
}
static void
gdb_cnterm(struct consdev *cp)
{
}
static int
gdb_cngetc(struct consdev *cp)
{
return -1;
}
static void
gdb_tx_puthex(int c)
{
const char *hex = "0123456789abcdef";
gdb_tx_char(hex[(c>>4)&0xf]);
gdb_tx_char(hex[(c>>0)&0xf]);
}
static void
gdb_cnflush(void *arg)
{
struct gdbcons *gc = arg;
int i;
gdb_tx_begin('O');
for (i = 0; i < gc->npending; i++)
gdb_tx_puthex(gc->buf[i]);
gdb_tx_end();
gc->npending = 0;
}
/*
* This glop is to figure out when it's safe to use callouts
* to defer buffer flushing. There's probably a better way
* and/or an earlier point in the boot process when it's ok.
*/
static int calloutok = 0;
static void
oktousecallout(void *data __unused)
{
calloutok = 1;
}
SYSINIT(gdbhack, SI_SUB_RUN_SCHEDULER, SI_ORDER_ANY, oktousecallout, NULL)
static void
gdb_cnputc(struct consdev *cp, int c)
{
struct gdbcons *gc;
if (gdbcons_enable && gdb_cur != NULL && gdb_listening) {
gc = cp->cn_arg;
if (gc->npending != 0) {
/*
* Cancel any pending callout and flush the
* buffer if there's no space for this byte.
*/
if (calloutok)
callout_stop(&gc->flush);
if (gc->npending == sizeof(gc->buf))
gdb_cnflush(gc);
}
gc->buf[gc->npending++] = c;
/*
* Flush on end of line; this is especially helpful
* during boot when we don't have callouts to flush
* the buffer. Otherwise we defer flushing; a 1/4
* second is a guess.
*/
if (c == '\n')
gdb_cnflush(gc);
else if (calloutok)
callout_reset(&gc->flush, hz/4, gdb_cnflush, gc);
}
}
CONSOLE_DRIVER(gdb);
/*
* Our console device only gets attached if the system is booted
* with RB_MULTIPLE set so gdb_init also calls us to attach the
* console so we're setup regardless.
*/
void
gdb_consinit(void)
{
gdb_cnprobe(&gdb_consdev);
gdb_cninit(&gdb_consdev);
cnadd(&gdb_consdev);
}
|
