The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/gdb/gdb_cons.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2006 Sam Leffler
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  *
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
   16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   18  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   25  */
   26 
   27 /* 
   28  * Support for redirecting console msgs to gdb.  We register
   29  * a pseudo console to hook cnputc and send stuff to the gdb
   30  * port.  The only trickiness here is buffering output so this
   31  * isn't dog slow.
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: releng/8.0/sys/gdb/gdb_cons.c 177255 2008-03-16 13:02:04Z rwatson $");
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/cons.h>
   40 #include <sys/kdb.h>
   41 #include <sys/kernel.h>
   42 #include <sys/malloc.h>
   43 #include <sys/reboot.h>
   44 #include <sys/sysctl.h>
   45 
   46 #include <machine/gdb_machdep.h>
   47 #include <machine/kdb.h>
   48 
   49 #include <gdb/gdb.h>
   50 #include <gdb/gdb_int.h>
   51 
   52 struct gdbcons {
   53         int     npending;
   54         /* /2 for hex conversion, -6 for protocol glue */
   55         char    buf[GDB_BUFSZ/2 - 6];
   56         struct callout flush;
   57 };
   58 static struct gdbcons state = { -1 };
   59 
   60 static  int gdbcons_enable = 0;
   61 SYSCTL_INT(_debug, OID_AUTO, gdbcons, CTLFLAG_RW, &gdbcons_enable,
   62             0, "copy console messages to gdb");
   63 TUNABLE_INT("debug.gdbcons", &gdbcons_enable);
   64 
   65 static void
   66 gdb_cnprobe(struct consdev *cp)
   67 {
   68         sprintf(cp->cn_name, "gdb");
   69         cp->cn_pri = CN_LOW;            /* XXX no way to say "write only" */
   70 }
   71 
   72 static void
   73 gdb_cninit(struct consdev *cp)
   74 {
   75         struct gdbcons *c = &state;
   76 
   77         /* setup tx buffer and callout */
   78         if (c->npending == -1) {
   79                 c->npending = 0;
   80                 callout_init(&c->flush, CALLOUT_MPSAFE);
   81                 cp->cn_arg = c;
   82         }
   83 }
   84 
   85 static void
   86 gdb_cnterm(struct consdev *cp)
   87 {
   88 }
   89 
   90 static int
   91 gdb_cngetc(struct consdev *cp)
   92 {
   93         return -1;
   94 }
   95 
   96 static void
   97 gdb_tx_puthex(int c)
   98 {
   99         const char *hex = "0123456789abcdef";
  100 
  101         gdb_tx_char(hex[(c>>4)&0xf]);
  102         gdb_tx_char(hex[(c>>0)&0xf]);
  103 }
  104 
  105 static void
  106 gdb_cnflush(void *arg)
  107 {
  108         struct gdbcons *gc = arg;
  109         int i;
  110 
  111         gdb_tx_begin('O');
  112         for (i = 0; i < gc->npending; i++)
  113                 gdb_tx_puthex(gc->buf[i]);
  114         gdb_tx_end();
  115         gc->npending = 0;
  116 }
  117 
  118 /*
  119  * This glop is to figure out when it's safe to use callouts
  120  * to defer buffer flushing.  There's probably a better way
  121  * and/or an earlier point in the boot process when it's ok.
  122  */
  123 static int calloutok = 0;
  124 static void
  125 oktousecallout(void *data __unused)
  126 {
  127         calloutok = 1;
  128 }
  129 SYSINIT(gdbhack, SI_SUB_RUN_SCHEDULER, SI_ORDER_ANY, oktousecallout, NULL);
  130 
  131 static void
  132 gdb_cnputc(struct consdev *cp, int c)
  133 {
  134         struct gdbcons *gc;
  135 
  136         if (gdbcons_enable && gdb_cur != NULL && gdb_listening) {
  137                 gc = cp->cn_arg;
  138                 if (gc->npending != 0) {
  139                         /*
  140                          * Cancel any pending callout and flush the
  141                          * buffer if there's no space for this byte.
  142                          */
  143                         if (calloutok)
  144                                 callout_stop(&gc->flush);
  145                         if (gc->npending == sizeof(gc->buf))
  146                                 gdb_cnflush(gc);
  147                 }
  148                 gc->buf[gc->npending++] = c;
  149                 /*
  150                  * Flush on end of line; this is especially helpful
  151                  * during boot when we don't have callouts to flush
  152                  * the buffer.  Otherwise we defer flushing; a 1/4 
  153                  * second is a guess.
  154                  */
  155                 if (c == '\n')
  156                         gdb_cnflush(gc);
  157                 else if (calloutok)
  158                         callout_reset(&gc->flush, hz/4, gdb_cnflush, gc);
  159         }
  160 }
  161 
  162 CONSOLE_DRIVER(gdb);
  163 
  164 /*
  165  * Our console device only gets attached if the system is booted
  166  * with RB_MULTIPLE set so gdb_init also calls us to attach the
  167  * console so we're setup regardless.
  168  */
  169 void
  170 gdb_consinit(void)
  171 {
  172         gdb_cnprobe(&gdb_consdev);
  173         gdb_cninit(&gdb_consdev);
  174         cnadd(&gdb_consdev);
  175 }

Cache object: 4e2574cf83e67107b8d6e4072bc0ad47


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.