xref: /openbmc/u-boot/common/xyzModem.c (revision 274bced8)
1 /*
2  *==========================================================================
3  *
4  *      xyzModem.c
5  *
6  *      RedBoot stream handler for xyzModem protocol
7  *
8  *==========================================================================
9  * SPDX-License-Identifier:	eCos-2.0
10  *==========================================================================
11  *#####DESCRIPTIONBEGIN####
12  *
13  * Author(s):    gthomas
14  * Contributors: gthomas, tsmith, Yoshinori Sato
15  * Date:         2000-07-14
16  * Purpose:
17  * Description:
18  *
19  * This code is part of RedBoot (tm).
20  *
21  *####DESCRIPTIONEND####
22  *
23  *==========================================================================
24  */
25 #include <common.h>
26 #include <xyzModem.h>
27 #include <stdarg.h>
28 #include <crc.h>
29 
30 /* Assumption - run xyzModem protocol over the console port */
31 
32 /* Values magic to the protocol */
33 #define SOH 0x01
34 #define STX 0x02
35 #define EOT 0x04
36 #define ACK 0x06
37 #define BSP 0x08
38 #define NAK 0x15
39 #define CAN 0x18
40 #define EOF 0x1A		/* ^Z for DOS officionados */
41 
42 #define USE_YMODEM_LENGTH
43 
44 /* Data & state local to the protocol */
45 static struct
46 {
47 #ifdef REDBOOT
48   hal_virtual_comm_table_t *__chan;
49 #else
50   int *__chan;
51 #endif
52   unsigned char pkt[1024], *bufp;
53   unsigned char blk, cblk, crc1, crc2;
54   unsigned char next_blk;	/* Expected block */
55   int len, mode, total_retries;
56   int total_SOH, total_STX, total_CAN;
57   bool crc_mode, at_eof, tx_ack;
58 #ifdef USE_YMODEM_LENGTH
59   unsigned long file_length, read_length;
60 #endif
61 } xyz;
62 
63 #define xyzModem_CHAR_TIMEOUT            2000	/* 2 seconds */
64 #define xyzModem_MAX_RETRIES             20
65 #define xyzModem_MAX_RETRIES_WITH_CRC    10
66 #define xyzModem_CAN_COUNT                3	/* Wait for 3 CAN before quitting */
67 
68 
69 #ifndef REDBOOT			/*SB */
70 typedef int cyg_int32;
71 static int
72 CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
73 {
74 
75   ulong now = get_timer(0);
76   while (!tstc ())
77     {
78       if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
79         break;
80     }
81   if (tstc ())
82     {
83       *c = getc ();
84       return 1;
85     }
86   return 0;
87 }
88 
89 static void
90 CYGACC_COMM_IF_PUTC (char x, char y)
91 {
92   putc (y);
93 }
94 
95 /* Validate a hex character */
96 __inline__ static bool
97 _is_hex (char c)
98 {
99   return (((c >= '0') && (c <= '9')) ||
100 	  ((c >= 'A') && (c <= 'F')) || ((c >= 'a') && (c <= 'f')));
101 }
102 
103 /* Convert a single hex nibble */
104 __inline__ static int
105 _from_hex (char c)
106 {
107   int ret = 0;
108 
109   if ((c >= '0') && (c <= '9'))
110     {
111       ret = (c - '0');
112     }
113   else if ((c >= 'a') && (c <= 'f'))
114     {
115       ret = (c - 'a' + 0x0a);
116     }
117   else if ((c >= 'A') && (c <= 'F'))
118     {
119       ret = (c - 'A' + 0x0A);
120     }
121   return ret;
122 }
123 
124 /* Convert a character to lower case */
125 __inline__ static char
126 _tolower (char c)
127 {
128   if ((c >= 'A') && (c <= 'Z'))
129     {
130       c = (c - 'A') + 'a';
131     }
132   return c;
133 }
134 
135 /* Parse (scan) a number */
136 static bool
137 parse_num (char *s, unsigned long *val, char **es, char *delim)
138 {
139   bool first = true;
140   int radix = 10;
141   char c;
142   unsigned long result = 0;
143   int digit;
144 
145   while (*s == ' ')
146     s++;
147   while (*s)
148     {
149       if (first && (s[0] == '0') && (_tolower (s[1]) == 'x'))
150 	{
151 	  radix = 16;
152 	  s += 2;
153 	}
154       first = false;
155       c = *s++;
156       if (_is_hex (c) && ((digit = _from_hex (c)) < radix))
157 	{
158 	  /* Valid digit */
159 #ifdef CYGPKG_HAL_MIPS
160 	  /* FIXME: tx49 compiler generates 0x2539018 for MUL which */
161 	  /* isn't any good. */
162 	  if (16 == radix)
163 	    result = result << 4;
164 	  else
165 	    result = 10 * result;
166 	  result += digit;
167 #else
168 	  result = (result * radix) + digit;
169 #endif
170 	}
171       else
172 	{
173 	  if (delim != (char *) 0)
174 	    {
175 	      /* See if this character is one of the delimiters */
176 	      char *dp = delim;
177 	      while (*dp && (c != *dp))
178 		dp++;
179 	      if (*dp)
180 		break;		/* Found a good delimiter */
181 	    }
182 	  return false;		/* Malformatted number */
183 	}
184     }
185   *val = result;
186   if (es != (char **) 0)
187     {
188       *es = s;
189     }
190   return true;
191 }
192 
193 #endif
194 
195 #define USE_SPRINTF
196 #ifdef DEBUG
197 #ifndef USE_SPRINTF
198 /*
199  * Note: this debug setup only works if the target platform has two serial ports
200  * available so that the other one (currently only port 1) can be used for debug
201  * messages.
202  */
203 static int
204 zm_dprintf (char *fmt, ...)
205 {
206   int cur_console;
207   va_list args;
208 
209   va_start (args, fmt);
210 #ifdef REDBOOT
211   cur_console =
212     CYGACC_CALL_IF_SET_CONSOLE_COMM
213     (CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
214   CYGACC_CALL_IF_SET_CONSOLE_COMM (1);
215 #endif
216   diag_vprintf (fmt, args);
217 #ifdef REDBOOT
218   CYGACC_CALL_IF_SET_CONSOLE_COMM (cur_console);
219 #endif
220 }
221 
222 static void
223 zm_flush (void)
224 {
225 }
226 
227 #else
228 /*
229  * Note: this debug setup works by storing the strings in a fixed buffer
230  */
231 #define FINAL
232 #ifdef FINAL
233 static char *zm_out = (char *) 0x00380000;
234 static char *zm_out_start = (char *) 0x00380000;
235 #else
236 static char zm_buf[8192];
237 static char *zm_out = zm_buf;
238 static char *zm_out_start = zm_buf;
239 
240 #endif
241 static int
242 zm_dprintf (char *fmt, ...)
243 {
244   int len;
245   va_list args;
246 
247   va_start (args, fmt);
248   len = diag_vsprintf (zm_out, fmt, args);
249   zm_out += len;
250   return len;
251 }
252 
253 static void
254 zm_flush (void)
255 {
256 #ifdef REDBOOT
257   char *p = zm_out_start;
258   while (*p)
259     mon_write_char (*p++);
260 #endif
261   zm_out = zm_out_start;
262 }
263 #endif
264 
265 static void
266 zm_dump_buf (void *buf, int len)
267 {
268 #ifdef REDBOOT
269   diag_vdump_buf_with_offset (zm_dprintf, buf, len, 0);
270 #else
271 
272 #endif
273 }
274 
275 static unsigned char zm_buf[2048];
276 static unsigned char *zm_bp;
277 
278 static void
279 zm_new (void)
280 {
281   zm_bp = zm_buf;
282 }
283 
284 static void
285 zm_save (unsigned char c)
286 {
287   *zm_bp++ = c;
288 }
289 
290 static void
291 zm_dump (int line)
292 {
293   zm_dprintf ("Packet at line: %d\n", line);
294   zm_dump_buf (zm_buf, zm_bp - zm_buf);
295 }
296 
297 #define ZM_DEBUG(x) x
298 #else
299 #define ZM_DEBUG(x)
300 #endif
301 
302 /* Wait for the line to go idle */
303 static void
304 xyzModem_flush (void)
305 {
306   int res;
307   char c;
308   while (true)
309     {
310       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
311       if (!res)
312 	return;
313     }
314 }
315 
316 static int
317 xyzModem_get_hdr (void)
318 {
319   char c;
320   int res;
321   bool hdr_found = false;
322   int i, can_total, hdr_chars;
323   unsigned short cksum;
324 
325   ZM_DEBUG (zm_new ());
326   /* Find the start of a header */
327   can_total = 0;
328   hdr_chars = 0;
329 
330   if (xyz.tx_ack)
331     {
332       CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
333       xyz.tx_ack = false;
334     }
335   while (!hdr_found)
336     {
337       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
338       ZM_DEBUG (zm_save (c));
339       if (res)
340 	{
341 	  hdr_chars++;
342 	  switch (c)
343 	    {
344 	    case SOH:
345 	      xyz.total_SOH++;
346 	    case STX:
347 	      if (c == STX)
348 		xyz.total_STX++;
349 	      hdr_found = true;
350 	      break;
351 	    case CAN:
352 	      xyz.total_CAN++;
353 	      ZM_DEBUG (zm_dump (__LINE__));
354 	      if (++can_total == xyzModem_CAN_COUNT)
355 		{
356 		  return xyzModem_cancel;
357 		}
358 	      else
359 		{
360 		  /* Wait for multiple CAN to avoid early quits */
361 		  break;
362 		}
363 	    case EOT:
364 	      /* EOT only supported if no noise */
365 	      if (hdr_chars == 1)
366 		{
367 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
368 		  ZM_DEBUG (zm_dprintf ("ACK on EOT #%d\n", __LINE__));
369 		  ZM_DEBUG (zm_dump (__LINE__));
370 		  return xyzModem_eof;
371 		}
372 	    default:
373 	      /* Ignore, waiting for start of header */
374 	      ;
375 	    }
376 	}
377       else
378 	{
379 	  /* Data stream timed out */
380 	  xyzModem_flush ();	/* Toss any current input */
381 	  ZM_DEBUG (zm_dump (__LINE__));
382 	  CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
383 	  return xyzModem_timeout;
384 	}
385     }
386 
387   /* Header found, now read the data */
388   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.blk);
389   ZM_DEBUG (zm_save (xyz.blk));
390   if (!res)
391     {
392       ZM_DEBUG (zm_dump (__LINE__));
393       return xyzModem_timeout;
394     }
395   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.cblk);
396   ZM_DEBUG (zm_save (xyz.cblk));
397   if (!res)
398     {
399       ZM_DEBUG (zm_dump (__LINE__));
400       return xyzModem_timeout;
401     }
402   xyz.len = (c == SOH) ? 128 : 1024;
403   xyz.bufp = xyz.pkt;
404   for (i = 0; i < xyz.len; i++)
405     {
406       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
407       ZM_DEBUG (zm_save (c));
408       if (res)
409 	{
410 	  xyz.pkt[i] = c;
411 	}
412       else
413 	{
414 	  ZM_DEBUG (zm_dump (__LINE__));
415 	  return xyzModem_timeout;
416 	}
417     }
418   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc1);
419   ZM_DEBUG (zm_save (xyz.crc1));
420   if (!res)
421     {
422       ZM_DEBUG (zm_dump (__LINE__));
423       return xyzModem_timeout;
424     }
425   if (xyz.crc_mode)
426     {
427       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc2);
428       ZM_DEBUG (zm_save (xyz.crc2));
429       if (!res)
430 	{
431 	  ZM_DEBUG (zm_dump (__LINE__));
432 	  return xyzModem_timeout;
433 	}
434     }
435   ZM_DEBUG (zm_dump (__LINE__));
436   /* Validate the message */
437   if ((xyz.blk ^ xyz.cblk) != (unsigned char) 0xFF)
438     {
439       ZM_DEBUG (zm_dprintf
440 		("Framing error - blk: %x/%x/%x\n", xyz.blk, xyz.cblk,
441 		 (xyz.blk ^ xyz.cblk)));
442       ZM_DEBUG (zm_dump_buf (xyz.pkt, xyz.len));
443       xyzModem_flush ();
444       return xyzModem_frame;
445     }
446   /* Verify checksum/CRC */
447   if (xyz.crc_mode)
448     {
449       cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
450       if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
451 	{
452 	  ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
453 				xyz.crc1, xyz.crc2, cksum & 0xFFFF));
454 	  return xyzModem_cksum;
455 	}
456     }
457   else
458     {
459       cksum = 0;
460       for (i = 0; i < xyz.len; i++)
461 	{
462 	  cksum += xyz.pkt[i];
463 	}
464       if (xyz.crc1 != (cksum & 0xFF))
465 	{
466 	  ZM_DEBUG (zm_dprintf
467 		    ("Checksum error - recvd: %x, computed: %x\n", xyz.crc1,
468 		     cksum & 0xFF));
469 	  return xyzModem_cksum;
470 	}
471     }
472   /* If we get here, the message passes [structural] muster */
473   return 0;
474 }
475 
476 int
477 xyzModem_stream_open (connection_info_t * info, int *err)
478 {
479 #ifdef REDBOOT
480   int console_chan;
481 #endif
482   int stat = 0;
483   int retries = xyzModem_MAX_RETRIES;
484   int crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;
485 
486 /*    ZM_DEBUG(zm_out = zm_out_start); */
487 #ifdef xyzModem_zmodem
488   if (info->mode == xyzModem_zmodem)
489     {
490       *err = xyzModem_noZmodem;
491       return -1;
492     }
493 #endif
494 
495 #ifdef REDBOOT
496   /* Set up the I/O channel.  Note: this allows for using a different port in the future */
497   console_chan =
498     CYGACC_CALL_IF_SET_CONSOLE_COMM
499     (CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
500   if (info->chan >= 0)
501     {
502       CYGACC_CALL_IF_SET_CONSOLE_COMM (info->chan);
503     }
504   else
505     {
506       CYGACC_CALL_IF_SET_CONSOLE_COMM (console_chan);
507     }
508   xyz.__chan = CYGACC_CALL_IF_CONSOLE_PROCS ();
509 
510   CYGACC_CALL_IF_SET_CONSOLE_COMM (console_chan);
511   CYGACC_COMM_IF_CONTROL (*xyz.__chan, __COMMCTL_SET_TIMEOUT,
512 			  xyzModem_CHAR_TIMEOUT);
513 #else
514 /* TODO: CHECK ! */
515   int dummy = 0;
516   xyz.__chan = &dummy;
517 #endif
518   xyz.len = 0;
519   xyz.crc_mode = true;
520   xyz.at_eof = false;
521   xyz.tx_ack = false;
522   xyz.mode = info->mode;
523   xyz.total_retries = 0;
524   xyz.total_SOH = 0;
525   xyz.total_STX = 0;
526   xyz.total_CAN = 0;
527 #ifdef USE_YMODEM_LENGTH
528   xyz.read_length = 0;
529   xyz.file_length = 0;
530 #endif
531 
532   CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
533 
534   if (xyz.mode == xyzModem_xmodem)
535     {
536       /* X-modem doesn't have an information header - exit here */
537       xyz.next_blk = 1;
538       return 0;
539     }
540 
541   while (retries-- > 0)
542     {
543       stat = xyzModem_get_hdr ();
544       if (stat == 0)
545 	{
546 	  /* Y-modem file information header */
547 	  if (xyz.blk == 0)
548 	    {
549 #ifdef USE_YMODEM_LENGTH
550 	      /* skip filename */
551 	      while (*xyz.bufp++);
552 	      /* get the length */
553 	      parse_num ((char *) xyz.bufp, &xyz.file_length, NULL, " ");
554 #endif
555 	      /* The rest of the file name data block quietly discarded */
556 	      xyz.tx_ack = true;
557 	    }
558 	  xyz.next_blk = 1;
559 	  xyz.len = 0;
560 	  return 0;
561 	}
562       else if (stat == xyzModem_timeout)
563 	{
564 	  if (--crc_retries <= 0)
565 	    xyz.crc_mode = false;
566 	  CYGACC_CALL_IF_DELAY_US (5 * 100000);	/* Extra delay for startup */
567 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
568 	  xyz.total_retries++;
569 	  ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
570 	}
571       if (stat == xyzModem_cancel)
572 	{
573 	  break;
574 	}
575     }
576   *err = stat;
577   ZM_DEBUG (zm_flush ());
578   return -1;
579 }
580 
581 int
582 xyzModem_stream_read (char *buf, int size, int *err)
583 {
584   int stat, total, len;
585   int retries;
586 
587   total = 0;
588   stat = xyzModem_cancel;
589   /* Try and get 'size' bytes into the buffer */
590   while (!xyz.at_eof && (size > 0))
591     {
592       if (xyz.len == 0)
593 	{
594 	  retries = xyzModem_MAX_RETRIES;
595 	  while (retries-- > 0)
596 	    {
597 	      stat = xyzModem_get_hdr ();
598 	      if (stat == 0)
599 		{
600 		  if (xyz.blk == xyz.next_blk)
601 		    {
602 		      xyz.tx_ack = true;
603 		      ZM_DEBUG (zm_dprintf
604 				("ACK block %d (%d)\n", xyz.blk, __LINE__));
605 		      xyz.next_blk = (xyz.next_blk + 1) & 0xFF;
606 
607 #if defined(xyzModem_zmodem) || defined(USE_YMODEM_LENGTH)
608 		      if (xyz.mode == xyzModem_xmodem || xyz.file_length == 0)
609 			{
610 #else
611 		      if (1)
612 			{
613 #endif
614 			  /* Data blocks can be padded with ^Z (EOF) characters */
615 			  /* This code tries to detect and remove them */
616 			  if ((xyz.bufp[xyz.len - 1] == EOF) &&
617 			      (xyz.bufp[xyz.len - 2] == EOF) &&
618 			      (xyz.bufp[xyz.len - 3] == EOF))
619 			    {
620 			      while (xyz.len
621 				     && (xyz.bufp[xyz.len - 1] == EOF))
622 				{
623 				  xyz.len--;
624 				}
625 			    }
626 			}
627 
628 #ifdef USE_YMODEM_LENGTH
629 		      /*
630 		       * See if accumulated length exceeds that of the file.
631 		       * If so, reduce size (i.e., cut out pad bytes)
632 		       * Only do this for Y-modem (and Z-modem should it ever
633 		       * be supported since it can fall back to Y-modem mode).
634 		       */
635 		      if (xyz.mode != xyzModem_xmodem && 0 != xyz.file_length)
636 			{
637 			  xyz.read_length += xyz.len;
638 			  if (xyz.read_length > xyz.file_length)
639 			    {
640 			      xyz.len -= (xyz.read_length - xyz.file_length);
641 			    }
642 			}
643 #endif
644 		      break;
645 		    }
646 		  else if (xyz.blk == ((xyz.next_blk - 1) & 0xFF))
647 		    {
648 		      /* Just re-ACK this so sender will get on with it */
649 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
650 		      continue;	/* Need new header */
651 		    }
652 		  else
653 		    {
654 		      stat = xyzModem_sequence;
655 		    }
656 		}
657 	      if (stat == xyzModem_cancel)
658 		{
659 		  break;
660 		}
661 	      if (stat == xyzModem_eof)
662 		{
663 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
664 		  ZM_DEBUG (zm_dprintf ("ACK (%d)\n", __LINE__));
665 		  if (xyz.mode == xyzModem_ymodem)
666 		    {
667 		      CYGACC_COMM_IF_PUTC (*xyz.__chan,
668 					   (xyz.crc_mode ? 'C' : NAK));
669 		      xyz.total_retries++;
670 		      ZM_DEBUG (zm_dprintf ("Reading Final Header\n"));
671 		      stat = xyzModem_get_hdr ();
672 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
673 		      ZM_DEBUG (zm_dprintf ("FINAL ACK (%d)\n", __LINE__));
674 		    }
675 		  xyz.at_eof = true;
676 		  break;
677 		}
678 	      CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
679 	      xyz.total_retries++;
680 	      ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
681 	    }
682 	  if (stat < 0)
683 	    {
684 	      *err = stat;
685 	      xyz.len = -1;
686 	      return total;
687 	    }
688 	}
689       /* Don't "read" data from the EOF protocol package */
690       if (!xyz.at_eof)
691 	{
692 	  len = xyz.len;
693 	  if (size < len)
694 	    len = size;
695 	  memcpy (buf, xyz.bufp, len);
696 	  size -= len;
697 	  buf += len;
698 	  total += len;
699 	  xyz.len -= len;
700 	  xyz.bufp += len;
701 	}
702     }
703   return total;
704 }
705 
706 void
707 xyzModem_stream_close (int *err)
708 {
709   diag_printf
710     ("xyzModem - %s mode, %d(SOH)/%d(STX)/%d(CAN) packets, %d retries\n",
711      xyz.crc_mode ? "CRC" : "Cksum", xyz.total_SOH, xyz.total_STX,
712      xyz.total_CAN, xyz.total_retries);
713   ZM_DEBUG (zm_flush ());
714 }
715 
716 /* Need to be able to clean out the input buffer, so have to take the */
717 /* getc */
718 void
719 xyzModem_stream_terminate (bool abort, int (*getc) (void))
720 {
721   int c;
722 
723   if (abort)
724     {
725       ZM_DEBUG (zm_dprintf ("!!!! TRANSFER ABORT !!!!\n"));
726       switch (xyz.mode)
727 	{
728 	case xyzModem_xmodem:
729 	case xyzModem_ymodem:
730 	  /* The X/YMODEM Spec seems to suggest that multiple CAN followed by an equal */
731 	  /* number of Backspaces is a friendly way to get the other end to abort. */
732 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
733 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
734 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
735 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
736 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
737 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
738 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
739 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
740 	  /* Now consume the rest of what's waiting on the line. */
741 	  ZM_DEBUG (zm_dprintf ("Flushing serial line.\n"));
742 	  xyzModem_flush ();
743 	  xyz.at_eof = true;
744 	  break;
745 #ifdef xyzModem_zmodem
746 	case xyzModem_zmodem:
747 	  /* Might support it some day I suppose. */
748 #endif
749 	  break;
750 	}
751     }
752   else
753     {
754       ZM_DEBUG (zm_dprintf ("Engaging cleanup mode...\n"));
755       /*
756        * Consume any trailing crap left in the inbuffer from
757        * previous received blocks. Since very few files are an exact multiple
758        * of the transfer block size, there will almost always be some gunk here.
759        * If we don't eat it now, RedBoot will think the user typed it.
760        */
761       ZM_DEBUG (zm_dprintf ("Trailing gunk:\n"));
762       while ((c = (*getc) ()) > -1)
763         ;
764       ZM_DEBUG (zm_dprintf ("\n"));
765       /*
766        * Make a small delay to give terminal programs like minicom
767        * time to get control again after their file transfer program
768        * exits.
769        */
770       CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
771     }
772 }
773 
774 char *
775 xyzModem_error (int err)
776 {
777   switch (err)
778     {
779     case xyzModem_access:
780       return "Can't access file";
781       break;
782     case xyzModem_noZmodem:
783       return "Sorry, zModem not available yet";
784       break;
785     case xyzModem_timeout:
786       return "Timed out";
787       break;
788     case xyzModem_eof:
789       return "End of file";
790       break;
791     case xyzModem_cancel:
792       return "Cancelled";
793       break;
794     case xyzModem_frame:
795       return "Invalid framing";
796       break;
797     case xyzModem_cksum:
798       return "CRC/checksum error";
799       break;
800     case xyzModem_sequence:
801       return "Block sequence error";
802       break;
803     default:
804       return "Unknown error";
805       break;
806     }
807 }
808 
809 /*
810  * RedBoot interface
811  */
812 #if 0				/* SB */
813 GETC_IO_FUNCS (xyzModem_io, xyzModem_stream_open, xyzModem_stream_close,
814 	       xyzModem_stream_terminate, xyzModem_stream_read,
815 	       xyzModem_error);
816 RedBoot_load (xmodem, xyzModem_io, false, false, xyzModem_xmodem);
817 RedBoot_load (ymodem, xyzModem_io, false, false, xyzModem_ymodem);
818 #endif
819