binutils-gdb/gdb/xmodem.c

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/* 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_stderr);
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.");
}