summaryrefslogtreecommitdiff
path: root/gdb/xmodem.c
blob: 8257ea806bff84d1d2c862b79ce157c88455e78e (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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/* XMODEM support for GDB, the GNU debugger.
   Copyright 1995 Free Software Foundation, Inc.

   This file is part of GDB.

   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.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "serial.h"
#include "target.h"
#include "xmodem.h"

/* These definitions are for xmodem protocol. */

#define SOH	0x01
#define STX	0x02
#define ACK	0x06
#define NAK	0x15
#define EOT	0x04
#define CANCEL	0x18

static int blknum;		/* XMODEM block number */
static int crcflag;		/* Sez we are using CRC's instead of cksums */

static int
readchar (desc, timeout)
     serial_t desc;
     int timeout;
{
  int c;

  c = SERIAL_READCHAR (desc, timeout);

  if (remote_debug > 0)
    fputc_unfiltered (c, gdb_stdlog);

  if (c >= 0)
    return c;

  if (c == SERIAL_TIMEOUT)
    error ("Timeout reading from remote system.");

  perror_with_name ("xmodem.c:readchar()");
}

#define CRC16 0x1021		/* Generator polynomial (X^16 + X^12 + X^5 + 1) */

static unsigned short *crctab;

/* Call this to init the fast CRC-16 calculation table.  */

static void
crcinit ()
{
  static int crctab_inited = 0;
  int val;

  if (crctab_inited == 1)
    return;

  crctab = xmalloc (256 * sizeof (short));

  for (val = 0; val <= 255; val++)
    {
      int i;
      unsigned int crc;

      crc = val << 8;

      for (i = 0; i < 8; ++i)
	{
	  crc <<= 1;

	  if (crc & 0x10000)
	    crc ^= CRC16;
	}

      crctab[val] = crc;
    }

  crctab_inited = 1;
}

/* Calculate a CRC-16 for the LEN byte message pointed at by P.  */

static unsigned short
docrc (p, len)
     unsigned char *p;
     int len;
{
  unsigned short crc = 0;

  while (len-- > 0)
    crc = (crc << 8) ^ crctab[(crc >> 8) ^ *p++];

  return crc;
}

/* Start up the transmit process.  Reset state variables.  Wait for receiver to
   send NAK or CRC request.  */

int
xmodem_init_xfer (desc)
     serial_t desc;
{
  int c;
  int i;

  blknum = 1;
  crcflag = 0;
  crcinit ();

  for (i = 1; i <= 10; i++)
    {
      c = readchar (desc, 6);

      switch (c)
	{
	case 'C':
	  crcflag = 1;
	case NAK:
	  return 0;
	default:
	  fprintf_unfiltered (gdb_stderr, "xmodem_init_xfer: Got unexpected character %c (0%o)\n", c, c);
	  continue;
	case CANCEL:		/* target aborted load */
	  fprintf_unfiltered (gdb_stderr, "Got a CANCEL from the target.\n");
	  continue;
	}
    }
  error ("xmodem_init_xfer:  Too many unexpected characters.");
}

/* Take 128 bytes of data and make a packet out of it.

 *      Each packet looks like this:
 *      +-----+-------+-------+------+-----+
 *      | SOH | Seq1. | Seq2. | data | SUM |
 *      +-----+-------+-------+------+-----+
 *      SOH  = 0x01
 *      Seq1 = The sequence number.
 *      Seq2 = The complement of the sequence number.
 *      Data = A 128 bytes of data.
 *      SUM  = Add the contents of the 128 bytes and use the low-order
 *             8 bits of the result.
 *
 * send_xmodem_packet fills in the XMODEM fields of PACKET and sends it to the
 * remote system.  PACKET must be XMODEM_PACKETSIZE bytes long.  The data must
 * start 3 bytes after the beginning of the packet to leave room for the
 * XMODEM header.  LEN is the length of the data portion of the packet (and
 * must be <= 128 bytes).  If it is < 128 bytes, ^Z padding will be added.
 */

void
xmodem_send_packet (desc, packet, len, hashmark)
     serial_t desc;
     unsigned char *packet;
     int len;
     int hashmark;
{
  int i;
  int retries;
  int pktlen;
  int datasize;

  /* build the packet header */

  packet[1] = blknum;
  packet[2] = ~blknum;

  blknum++;

  if (len <= XMODEM_DATASIZE)
    {
      packet[0] = SOH;
      datasize = XMODEM_DATASIZE;
    }
  else if (len <= XMODEM_1KDATASIZE)
    {
      packet[0] = STX;
      datasize = XMODEM_1KDATASIZE;
    }
  else
    abort ();			/* Packet way too large */

  /* Add ^Z padding if packet < 128 (or 1024) bytes */

  memset (packet + 3 + len, '\026', datasize - len);

  if (crcflag)
    {
      int crc;

      crc = docrc (packet + 3, datasize);

      packet[3 + datasize] = crc >> 8;
      packet[3 + datasize + 1] = crc;
      pktlen = datasize + 5;
    }
  else
    {
      int sum;

      sum = 0;
      for (i = 3; i < datasize + 3; i++)
	sum += packet[i];

      packet[3 + datasize] = sum;	/* add the checksum */
      pktlen = datasize + 4;
    }

  for (retries = 3; retries >= 0; retries--)
    {
      int c;

      SERIAL_WRITE (desc, packet, pktlen);

      c = readchar (desc, 3);
      switch (c)
	{
	case ACK:
	  return;
	case NAK:
	  if (!hashmark)
	    continue;
	  putchar_unfiltered ('-');
	  gdb_flush (gdb_stdout);
	  continue;
	case CANCEL:
	  error ("xmodem_send_packet: Transfer aborted by receiver.");
	default:
	  fprintf_unfiltered (gdb_stderr, "xmodem_send_packet: Got unexpected character %c (0%o)\n", c, c);
	  continue;
	}
    }

  SERIAL_WRITE (desc, "\004", 1);	/* Send an EOT */

  error ("xmodem_send_packet:  Excessive retries.");
}

/* Finish off the transfer.  Send out the EOT, and wait for an ACK.  */

void
xmodem_finish_xfer (desc)
     serial_t desc;
{
  int retries;

  for (retries = 10; retries >= 0; retries--)
    {
      int c;

      SERIAL_WRITE (desc, "\004", 1);	/* Send an EOT */

      c = readchar (desc, 3);
      switch (c)
	{
	case ACK:
	  return;
	case NAK:
	  continue;
	case CANCEL:
	  error ("xmodem_finish_xfer: Transfer aborted by receiver.");
	default:
	  fprintf_unfiltered (gdb_stderr, "xmodem_send_packet: Got unexpected character %c (0%o)\n", c, c);
	  continue;
	}
    }

  error ("xmodem_finish_xfer:  Excessive retries.");
}