gdb/gdbserver/remote-utils.c

   1 /* Remote utility routines for the remote server for GDB.
   2    Copyright (C) 1986, 1989, 1993 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include <stdio.h>
  22 #include <signal.h>
  23 #include <sys/wait.h>
  24 #include <sys/ioctl.h>
  25 #include <a.out.h>
  26 #include <sys/file.h>
  27 #include <sgtty.h>
  28
  29 extern int remote_desc;
  30 extern int remote_debugging;
  31 extern int kiodebug;
  32
  33 void remote_open ();
  34 void remote_send ();
  35 void putpkt ();
  36 void getpkt ();
  37
  38 void write_ok ();
  39 void write_enn ();
  40 void convert_ascii_to_int ();
  41 void convert_int_to_ascii ();
  42 void prepare_resume_reply ();
  43
  44 /* Open a connection to a remote debugger.
  45    NAME is the filename used for communication.  */
  46
  47 void
  48 remote_open (name, from_tty)
  49      char *name;
  50      int from_tty;
  51 {
  52   struct sgttyb sg;
  53
  54   remote_debugging = 0;
  55
  56   remote_desc = open (name, O_RDWR);
  57   if (remote_desc < 0)
  58     perror_with_name ("Could not open remote device");
  59
  60   ioctl (remote_desc, TIOCGETP, &sg);
  61   sg.sg_flags = RAW;
  62   ioctl (remote_desc, TIOCSETP, &sg);
  63
  64   fprintf (stderr, "Remote debugging using %s\n", name);
  65   remote_debugging = 1;
  66 }
  67
  68 /* Convert hex digit A to a number.  */
  69
  70 static int
  71 fromhex (a)
  72      int a;
  73 {
  74   if (a >= '0' && a <= '9')
  75     return a - '0';
  76   else if (a >= 'a' && a <= 'f')
  77     return a - 'a' + 10;
  78   else
  79     error ("Reply contains invalid hex digit");
  80 }
  81
  82 /* Convert number NIB to a hex digit.  */
  83
  84 static int
  85 tohex (nib)
  86      int nib;
  87 {
  88   if (nib < 10)
  89     return '0' + nib;
  90   else
  91     return 'a' + nib - 10;
  92 }
  93
  94 /* Send the command in BUF to the remote machine,
  95    and read the reply into BUF.
  96    Report an error if we get an error reply.  */
  97
  98 void
  99 remote_send (buf)
 100      char *buf;
 101 {
 102   putpkt (buf);
 103   getpkt (buf);
 104
 105   if (buf[0] == 'E')
 106     error ("Remote failure reply: E");
 107 }
 108
 109 /* Send a packet to the remote machine, with error checking.
 110    The data of the packet is in BUF.  */
 111
 112 void
 113 putpkt (buf)
 114      char *buf;
 115 {
 116   int i;
 117   unsigned char csum = 0;
 118   char buf2[2000];
 119   char buf3[1];
 120   int cnt = strlen (buf);
 121   char *p;
 122
 123   /* Copy the packet into buffer BUF2, encapsulating it
 124      and giving it a checksum.  */
 125
 126   p = buf2;
 127   *p++ = '$';
 128
 129   for (i = 0; i < cnt; i++)
 130     {
 131       csum += buf[i];
 132       *p++ = buf[i];
 133     }
 134   *p++ = '#';
 135   *p++ = tohex ((csum >> 4) & 0xf);
 136   *p++ = tohex (csum & 0xf);
 137
 138   /* Send it over and over until we get a positive ack.  */
 139
 140   do
 141     {
 142       write (remote_desc, buf2, p - buf2);
 143       read (remote_desc, buf3, 1);
 144     }
 145   while (buf3[0] != '+');
 146 }
 147
 148 static int
 149 readchar ()
 150 {
 151   char buf[1];
 152   while (read (remote_desc, buf, 1) != 1);
 153   return buf[0] & 0x7f;
 154 }
 155
 156 /* Read a packet from the remote machine, with error checking,
 157    and store it in BUF.  */
 158
 159 void
 160 getpkt (buf)
 161      char *buf;
 162 {
 163   char *bp;
 164   unsigned char csum, c, c1, c2;
 165   extern kiodebug;
 166
 167   while (1)
 168     {
 169       csum = 0;
 170       while ((c = readchar ()) != '$');
 171
 172       bp = buf;
 173       while (1)
 174         {
 175           c = readchar ();
 176           if (c == '#')
 177             break;
 178           *bp++ = c;
 179           csum += c;
 180         }
 181       *bp = 0;
 182
 183       c1 = fromhex (readchar ());
 184       c2 = fromhex (readchar ());
 185       if (csum == (c1 << 4) + c2)
 186         break;
 187
 188       fprintf (stderr, "Bad checksum, sentsum=0x%x, csum=0x%x, buf=%s\n",
 189                (c1 << 4) + c2, csum, buf);
 190       write (remote_desc, "-", 1);
 191     }
 192
 193   write (remote_desc, "+", 1);
 194 }
 195
 196 void
 197 write_ok (buf)
 198      char *buf;
 199 {
 200   buf[0] = 'O';
 201   buf[1] = 'k';
 202   buf[2] = '\0';
 203 }
 204
 205 void
 206 write_enn (buf)
 207      char *buf;
 208 {
 209   buf[0] = 'E';
 210   buf[1] = 'N';
 211   buf[2] = 'N';
 212   buf[3] = '\0';
 213 }
 214
 215 void
 216 convert_int_to_ascii (from, to, n)
 217      char *from, *to;
 218      int n;
 219 {
 220   int nib;
 221   char ch;
 222   while (n--)
 223     {
 224       ch = *from++;
 225       nib = ((ch & 0xf0) >> 4) & 0x0f;
 226       *to++ = tohex (nib);
 227       nib = ch & 0x0f;
 228       *to++ = tohex (nib);
 229     }
 230   *to++ = 0;
 231 }
 232
 233
 234 void
 235 convert_ascii_to_int (from, to, n)
 236      char *from, *to;
 237      int n;
 238 {
 239   int nib1, nib2;
 240   while (n--)
 241     {
 242       nib1 = fromhex (*from++);
 243       nib2 = fromhex (*from++);
 244       *to++ = (((nib1 & 0x0f) << 4) & 0xf0) | (nib2 & 0x0f);
 245     }
 246 }
 247
 248 static char *
 249 outreg(regno, buf)
 250      int regno;
 251      char *buf;
 252 {
 253   extern char registers[];
 254
 255   *buf++ = tohex (regno >> 4);
 256   *buf++ = tohex (regno & 0xf);
 257   *buf++ = ':';
 258   convert_int_to_ascii (&registers[REGISTER_BYTE (regno)], buf, 4);
 259   buf += 8;
 260   *buf++ = ';';
 261
 262   return buf;
 263 }
 264
 265 void
 266 prepare_resume_reply (buf, status, signal)
 267      char *buf, status;
 268      unsigned char signal;
 269 {
 270   int nib;
 271   char ch;
 272
 273   *buf++ = 'T';
 274
 275   nib = ((signal & 0xf0) >> 4);
 276   *buf++ = tohex (nib);
 277   nib = signal & 0x0f;
 278   *buf++ = tohex (nib);
 279
 280   buf = outreg (PC_REGNUM, buf);
 281   buf = outreg (FP_REGNUM, buf);
 282   buf = outreg (SP_REGNUM, buf);
 283 #ifdef NPC_REGNUM
 284   buf = outreg (NPC_REGNUM, buf);
 285 #endif
 286 #ifdef O7_REGNUM
 287   buf = outreg (O7_REGNUM, buf);
 288 #endif
 289
 290   *buf++ = 0;
 291 }
 292
 293 void
 294 decode_m_packet (from, mem_addr_ptr, len_ptr)
 295      char *from;
 296      unsigned int *mem_addr_ptr, *len_ptr;
 297 {
 298   int i = 0, j = 0;
 299   char ch;
 300   *mem_addr_ptr = *len_ptr = 0;
 301
 302   while ((ch = from[i++]) != ',')
 303     {
 304       *mem_addr_ptr = *mem_addr_ptr << 4;
 305       *mem_addr_ptr |= fromhex (ch) & 0x0f;
 306     }
 307
 308   for (j = 0; j < 4; j++)
 309     {
 310       if ((ch = from[i++]) == 0)
 311         break;
 312       *len_ptr = *len_ptr << 4;
 313       *len_ptr |= fromhex (ch) & 0x0f;
 314     }
 315 }
 316
 317 void
 318 decode_M_packet (from, mem_addr_ptr, len_ptr, to)
 319      char *from, *to;
 320      unsigned int *mem_addr_ptr, *len_ptr;
 321 {
 322   int i = 0, j = 0;
 323   char ch;
 324   *mem_addr_ptr = *len_ptr = 0;
 325
 326   while ((ch = from[i++]) != ',')
 327     {
 328       *mem_addr_ptr = *mem_addr_ptr << 4;
 329       *mem_addr_ptr |= fromhex (ch) & 0x0f;
 330     }
 331
 332   while ((ch = from[i++]) != ':')
 333     {
 334       *len_ptr = *len_ptr << 4;
 335       *len_ptr |= fromhex (ch) & 0x0f;
 336     }
 337
 338   convert_ascii_to_int (&from[i++], to, *len_ptr);
 339 }