xref: /openbmc/u-boot/common/xyzModem.c (revision e11ef3d2) 
1 // SPDX-License-Identifier: eCos-2.0
2 /*
3  *==========================================================================
4  *
5  *      xyzModem.c
6  *
7  *      RedBoot stream handler for xyzModem protocol
8  *
9  *==========================================================================
10  *#####DESCRIPTIONBEGIN####
11  *
12  * Author(s):    gthomas
13  * Contributors: gthomas, tsmith, Yoshinori Sato
14  * Date:         2000-07-14
15  * Purpose:
16  * Description:
17  *
18  * This code is part of RedBoot (tm).
19  *
20  *####DESCRIPTIONEND####
21  *
22  *==========================================================================
23  */
24 #include <common.h>
25 #include <xyzModem.h>
26 #include <stdarg.h>
27 #include <u-boot/crc.h>
28 
29 /* Assumption - run xyzModem protocol over the console port */
30 
31 /* Values magic to the protocol */
32 #define SOH 0x01
33 #define STX 0x02
34 #define EOT 0x04
35 #define ACK 0x06
36 #define BSP 0x08
37 #define NAK 0x15
38 #define CAN 0x18
39 #define EOF 0x1A		/* ^Z for DOS officionados */
40 
41 /* Data & state local to the protocol */
42 static struct
43 {
44   int *__chan;
45   unsigned char pkt[1024], *bufp;
46   unsigned char blk, cblk, crc1, crc2;
47   unsigned char next_blk;	/* Expected block */
48   int len, mode, total_retries;
49   int total_SOH, total_STX, total_CAN;
50   bool crc_mode, at_eof, tx_ack;
51   unsigned long file_length, read_length;
52 } xyz;
53 
54 #define xyzModem_CHAR_TIMEOUT            2000	/* 2 seconds */
55 #define xyzModem_MAX_RETRIES             20
56 #define xyzModem_MAX_RETRIES_WITH_CRC    10
57 #define xyzModem_CAN_COUNT                3	/* Wait for 3 CAN before quitting */
58 
59 
60 typedef int cyg_int32;
61 static int
62 CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
63 {
64 
65   ulong now = get_timer(0);
66   while (!tstc ())
67     {
68       if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
69         break;
70     }
71   if (tstc ())
72     {
73       *c = getc ();
74       return 1;
75     }
76   return 0;
77 }
78 
79 static void
80 CYGACC_COMM_IF_PUTC (char x, char y)
81 {
82   putc (y);
83 }
84 
85 /* Validate a hex character */
86 __inline__ static bool
87 _is_hex (char c)
88 {
89   return (((c >= '0') && (c <= '9')) ||
90 	  ((c >= 'A') && (c <= 'F')) || ((c >= 'a') && (c <= 'f')));
91 }
92 
93 /* Convert a single hex nibble */
94 __inline__ static int
95 _from_hex (char c)
96 {
97   int ret = 0;
98 
99   if ((c >= '0') && (c <= '9'))
100     {
101       ret = (c - '0');
102     }
103   else if ((c >= 'a') && (c <= 'f'))
104     {
105       ret = (c - 'a' + 0x0a);
106     }
107   else if ((c >= 'A') && (c <= 'F'))
108     {
109       ret = (c - 'A' + 0x0A);
110     }
111   return ret;
112 }
113 
114 /* Convert a character to lower case */
115 __inline__ static char
116 _tolower (char c)
117 {
118   if ((c >= 'A') && (c <= 'Z'))
119     {
120       c = (c - 'A') + 'a';
121     }
122   return c;
123 }
124 
125 /* Parse (scan) a number */
126 static bool
127 parse_num (char *s, unsigned long *val, char **es, char *delim)
128 {
129   bool first = true;
130   int radix = 10;
131   char c;
132   unsigned long result = 0;
133   int digit;
134 
135   while (*s == ' ')
136     s++;
137   while (*s)
138     {
139       if (first && (s[0] == '0') && (_tolower (s[1]) == 'x'))
140 	{
141 	  radix = 16;
142 	  s += 2;
143 	}
144       first = false;
145       c = *s++;
146       if (_is_hex (c) && ((digit = _from_hex (c)) < radix))
147 	{
148 	  /* Valid digit */
149 	  result = (result * radix) + digit;
150 	}
151       else
152 	{
153 	  if (delim != (char *) 0)
154 	    {
155 	      /* See if this character is one of the delimiters */
156 	      char *dp = delim;
157 	      while (*dp && (c != *dp))
158 		dp++;
159 	      if (*dp)
160 		break;		/* Found a good delimiter */
161 	    }
162 	  return false;		/* Malformatted number */
163 	}
164     }
165   *val = result;
166   if (es != (char **) 0)
167     {
168       *es = s;
169     }
170   return true;
171 }
172 
173 
174 #if defined(DEBUG) && !defined(CONFIG_USE_TINY_PRINTF)
175 /*
176  * Note: this debug setup works by storing the strings in a fixed buffer
177  */
178 static char zm_debug_buf[8192];
179 static char *zm_out = zm_debug_buf;
180 static char *zm_out_start = zm_debug_buf;
181 
182 static int
183 zm_dprintf(char *fmt, ...)
184 {
185 	int len;
186 	va_list args;
187 
188 	va_start(args, fmt);
189 	len = diag_vsprintf(zm_out, fmt, args);
190 	va_end(args);
191 	zm_out += len;
192 	return len;
193 }
194 
195 static void
196 zm_flush (void)
197 {
198   zm_out = zm_out_start;
199 }
200 
201 static void
202 zm_dump_buf (void *buf, int len)
203 {
204 
205 }
206 
207 static unsigned char zm_buf[2048];
208 static unsigned char *zm_bp;
209 
210 static void
211 zm_new (void)
212 {
213   zm_bp = zm_buf;
214 }
215 
216 static void
217 zm_save (unsigned char c)
218 {
219   *zm_bp++ = c;
220 }
221 
222 static void
223 zm_dump (int line)
224 {
225   zm_dprintf ("Packet at line: %d\n", line);
226   zm_dump_buf (zm_buf, zm_bp - zm_buf);
227 }
228 
229 #define ZM_DEBUG(x) x
230 #else
231 #define ZM_DEBUG(x)
232 #endif
233 
234 /* Wait for the line to go idle */
235 static void
236 xyzModem_flush (void)
237 {
238   int res;
239   char c;
240   while (true)
241     {
242       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
243       if (!res)
244 	return;
245     }
246 }
247 
248 static int
249 xyzModem_get_hdr (void)
250 {
251   char c;
252   int res;
253   bool hdr_found = false;
254   int i, can_total, hdr_chars;
255   unsigned short cksum;
256 
257   ZM_DEBUG (zm_new ());
258   /* Find the start of a header */
259   can_total = 0;
260   hdr_chars = 0;
261 
262   if (xyz.tx_ack)
263     {
264       CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
265       xyz.tx_ack = false;
266     }
267   while (!hdr_found)
268     {
269       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
270       ZM_DEBUG (zm_save (c));
271       if (res)
272 	{
273 	  hdr_chars++;
274 	  switch (c)
275 	    {
276 	    case SOH:
277 	      xyz.total_SOH++;
278 	    case STX:
279 	      if (c == STX)
280 		xyz.total_STX++;
281 	      hdr_found = true;
282 	      break;
283 	    case CAN:
284 	      xyz.total_CAN++;
285 	      ZM_DEBUG (zm_dump (__LINE__));
286 	      if (++can_total == xyzModem_CAN_COUNT)
287 		{
288 		  return xyzModem_cancel;
289 		}
290 	      else
291 		{
292 		  /* Wait for multiple CAN to avoid early quits */
293 		  break;
294 		}
295 	    case EOT:
296 	      /* EOT only supported if no noise */
297 	      if (hdr_chars == 1)
298 		{
299 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
300 		  ZM_DEBUG (zm_dprintf ("ACK on EOT #%d\n", __LINE__));
301 		  ZM_DEBUG (zm_dump (__LINE__));
302 		  return xyzModem_eof;
303 		}
304 	    default:
305 	      /* Ignore, waiting for start of header */
306 	      ;
307 	    }
308 	}
309       else
310 	{
311 	  /* Data stream timed out */
312 	  xyzModem_flush ();	/* Toss any current input */
313 	  ZM_DEBUG (zm_dump (__LINE__));
314 	  CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
315 	  return xyzModem_timeout;
316 	}
317     }
318 
319   /* Header found, now read the data */
320   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.blk);
321   ZM_DEBUG (zm_save (xyz.blk));
322   if (!res)
323     {
324       ZM_DEBUG (zm_dump (__LINE__));
325       return xyzModem_timeout;
326     }
327   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.cblk);
328   ZM_DEBUG (zm_save (xyz.cblk));
329   if (!res)
330     {
331       ZM_DEBUG (zm_dump (__LINE__));
332       return xyzModem_timeout;
333     }
334   xyz.len = (c == SOH) ? 128 : 1024;
335   xyz.bufp = xyz.pkt;
336   for (i = 0; i < xyz.len; i++)
337     {
338       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
339       ZM_DEBUG (zm_save (c));
340       if (res)
341 	{
342 	  xyz.pkt[i] = c;
343 	}
344       else
345 	{
346 	  ZM_DEBUG (zm_dump (__LINE__));
347 	  return xyzModem_timeout;
348 	}
349     }
350   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc1);
351   ZM_DEBUG (zm_save (xyz.crc1));
352   if (!res)
353     {
354       ZM_DEBUG (zm_dump (__LINE__));
355       return xyzModem_timeout;
356     }
357   if (xyz.crc_mode)
358     {
359       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc2);
360       ZM_DEBUG (zm_save (xyz.crc2));
361       if (!res)
362 	{
363 	  ZM_DEBUG (zm_dump (__LINE__));
364 	  return xyzModem_timeout;
365 	}
366     }
367   ZM_DEBUG (zm_dump (__LINE__));
368   /* Validate the message */
369   if ((xyz.blk ^ xyz.cblk) != (unsigned char) 0xFF)
370     {
371       ZM_DEBUG (zm_dprintf
372 		("Framing error - blk: %x/%x/%x\n", xyz.blk, xyz.cblk,
373 		 (xyz.blk ^ xyz.cblk)));
374       ZM_DEBUG (zm_dump_buf (xyz.pkt, xyz.len));
375       xyzModem_flush ();
376       return xyzModem_frame;
377     }
378   /* Verify checksum/CRC */
379   if (xyz.crc_mode)
380     {
381       cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
382       if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
383 	{
384 	  ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
385 				xyz.crc1, xyz.crc2, cksum & 0xFFFF));
386 	  return xyzModem_cksum;
387 	}
388     }
389   else
390     {
391       cksum = 0;
392       for (i = 0; i < xyz.len; i++)
393 	{
394 	  cksum += xyz.pkt[i];
395 	}
396       if (xyz.crc1 != (cksum & 0xFF))
397 	{
398 	  ZM_DEBUG (zm_dprintf
399 		    ("Checksum error - recvd: %x, computed: %x\n", xyz.crc1,
400 		     cksum & 0xFF));
401 	  return xyzModem_cksum;
402 	}
403     }
404   /* If we get here, the message passes [structural] muster */
405   return 0;
406 }
407 
408 int
409 xyzModem_stream_open (connection_info_t * info, int *err)
410 {
411   int stat = 0;
412   int retries = xyzModem_MAX_RETRIES;
413   int crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;
414 
415 /*    ZM_DEBUG(zm_out = zm_out_start); */
416 #ifdef xyzModem_zmodem
417   if (info->mode == xyzModem_zmodem)
418     {
419       *err = xyzModem_noZmodem;
420       return -1;
421     }
422 #endif
423 
424 /* TODO: CHECK ! */
425   int dummy = 0;
426   xyz.__chan = &dummy;
427   xyz.len = 0;
428   xyz.crc_mode = true;
429   xyz.at_eof = false;
430   xyz.tx_ack = false;
431   xyz.mode = info->mode;
432   xyz.total_retries = 0;
433   xyz.total_SOH = 0;
434   xyz.total_STX = 0;
435   xyz.total_CAN = 0;
436   xyz.read_length = 0;
437   xyz.file_length = 0;
438 
439   CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
440 
441   if (xyz.mode == xyzModem_xmodem)
442     {
443       /* X-modem doesn't have an information header - exit here */
444       xyz.next_blk = 1;
445       return 0;
446     }
447 
448   while (retries-- > 0)
449     {
450       stat = xyzModem_get_hdr ();
451       if (stat == 0)
452 	{
453 	  /* Y-modem file information header */
454 	  if (xyz.blk == 0)
455 	    {
456 	      /* skip filename */
457 	      while (*xyz.bufp++);
458 	      /* get the length */
459 	      parse_num ((char *) xyz.bufp, &xyz.file_length, NULL, " ");
460 	      /* The rest of the file name data block quietly discarded */
461 	      xyz.tx_ack = true;
462 	    }
463 	  xyz.next_blk = 1;
464 	  xyz.len = 0;
465 	  return 0;
466 	}
467       else if (stat == xyzModem_timeout)
468 	{
469 	  if (--crc_retries <= 0)
470 	    xyz.crc_mode = false;
471 	  CYGACC_CALL_IF_DELAY_US (5 * 100000);	/* Extra delay for startup */
472 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
473 	  xyz.total_retries++;
474 	  ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
475 	}
476       if (stat == xyzModem_cancel)
477 	{
478 	  break;
479 	}
480     }
481   *err = stat;
482   ZM_DEBUG (zm_flush ());
483   return -1;
484 }
485 
486 int
487 xyzModem_stream_read (char *buf, int size, int *err)
488 {
489   int stat, total, len;
490   int retries;
491 
492   total = 0;
493   stat = xyzModem_cancel;
494   /* Try and get 'size' bytes into the buffer */
495   while (!xyz.at_eof && (size > 0))
496     {
497       if (xyz.len == 0)
498 	{
499 	  retries = xyzModem_MAX_RETRIES;
500 	  while (retries-- > 0)
501 	    {
502 	      stat = xyzModem_get_hdr ();
503 	      if (stat == 0)
504 		{
505 		  if (xyz.blk == xyz.next_blk)
506 		    {
507 		      xyz.tx_ack = true;
508 		      ZM_DEBUG (zm_dprintf
509 				("ACK block %d (%d)\n", xyz.blk, __LINE__));
510 		      xyz.next_blk = (xyz.next_blk + 1) & 0xFF;
511 
512 		      if (xyz.mode == xyzModem_xmodem || xyz.file_length == 0)
513 			{
514 			  /* Data blocks can be padded with ^Z (EOF) characters */
515 			  /* This code tries to detect and remove them */
516 			  if ((xyz.bufp[xyz.len - 1] == EOF) &&
517 			      (xyz.bufp[xyz.len - 2] == EOF) &&
518 			      (xyz.bufp[xyz.len - 3] == EOF))
519 			    {
520 			      while (xyz.len
521 				     && (xyz.bufp[xyz.len - 1] == EOF))
522 				{
523 				  xyz.len--;
524 				}
525 			    }
526 			}
527 
528 		      /*
529 		       * See if accumulated length exceeds that of the file.
530 		       * If so, reduce size (i.e., cut out pad bytes)
531 		       * Only do this for Y-modem (and Z-modem should it ever
532 		       * be supported since it can fall back to Y-modem mode).
533 		       */
534 		      if (xyz.mode != xyzModem_xmodem && 0 != xyz.file_length)
535 			{
536 			  xyz.read_length += xyz.len;
537 			  if (xyz.read_length > xyz.file_length)
538 			    {
539 			      xyz.len -= (xyz.read_length - xyz.file_length);
540 			    }
541 			}
542 		      break;
543 		    }
544 		  else if (xyz.blk == ((xyz.next_blk - 1) & 0xFF))
545 		    {
546 		      /* Just re-ACK this so sender will get on with it */
547 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
548 		      continue;	/* Need new header */
549 		    }
550 		  else
551 		    {
552 		      stat = xyzModem_sequence;
553 		    }
554 		}
555 	      if (stat == xyzModem_cancel)
556 		{
557 		  break;
558 		}
559 	      if (stat == xyzModem_eof)
560 		{
561 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
562 		  ZM_DEBUG (zm_dprintf ("ACK (%d)\n", __LINE__));
563 		  if (xyz.mode == xyzModem_ymodem)
564 		    {
565 		      CYGACC_COMM_IF_PUTC (*xyz.__chan,
566 					   (xyz.crc_mode ? 'C' : NAK));
567 		      xyz.total_retries++;
568 		      ZM_DEBUG (zm_dprintf ("Reading Final Header\n"));
569 		      stat = xyzModem_get_hdr ();
570 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
571 		      ZM_DEBUG (zm_dprintf ("FINAL ACK (%d)\n", __LINE__));
572 		    }
573 		  xyz.at_eof = true;
574 		  break;
575 		}
576 	      CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
577 	      xyz.total_retries++;
578 	      ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
579 	    }
580 	  if (stat < 0)
581 	    {
582 	      *err = stat;
583 	      xyz.len = -1;
584 	      return total;
585 	    }
586 	}
587       /* Don't "read" data from the EOF protocol package */
588       if (!xyz.at_eof)
589 	{
590 	  len = xyz.len;
591 	  if (size < len)
592 	    len = size;
593 	  memcpy (buf, xyz.bufp, len);
594 	  size -= len;
595 	  buf += len;
596 	  total += len;
597 	  xyz.len -= len;
598 	  xyz.bufp += len;
599 	}
600     }
601   return total;
602 }
603 
604 void
605 xyzModem_stream_close (int *err)
606 {
607   diag_printf
608     ("xyzModem - %s mode, %d(SOH)/%d(STX)/%d(CAN) packets, %d retries\n",
609      xyz.crc_mode ? "CRC" : "Cksum", xyz.total_SOH, xyz.total_STX,
610      xyz.total_CAN, xyz.total_retries);
611   ZM_DEBUG (zm_flush ());
612 }
613 
614 /* Need to be able to clean out the input buffer, so have to take the */
615 /* getc */
616 void
617 xyzModem_stream_terminate (bool abort, int (*getc) (void))
618 {
619   int c;
620 
621   if (abort)
622     {
623       ZM_DEBUG (zm_dprintf ("!!!! TRANSFER ABORT !!!!\n"));
624       switch (xyz.mode)
625 	{
626 	case xyzModem_xmodem:
627 	case xyzModem_ymodem:
628 	  /* The X/YMODEM Spec seems to suggest that multiple CAN followed by an equal */
629 	  /* number of Backspaces is a friendly way to get the other end to abort. */
630 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
631 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
632 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
633 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
634 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
635 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
636 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
637 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
638 	  /* Now consume the rest of what's waiting on the line. */
639 	  ZM_DEBUG (zm_dprintf ("Flushing serial line.\n"));
640 	  xyzModem_flush ();
641 	  xyz.at_eof = true;
642 	  break;
643 #ifdef xyzModem_zmodem
644 	case xyzModem_zmodem:
645 	  /* Might support it some day I suppose. */
646 #endif
647 	  break;
648 	}
649     }
650   else
651     {
652       ZM_DEBUG (zm_dprintf ("Engaging cleanup mode...\n"));
653       /*
654        * Consume any trailing crap left in the inbuffer from
655        * previous received blocks. Since very few files are an exact multiple
656        * of the transfer block size, there will almost always be some gunk here.
657        * If we don't eat it now, RedBoot will think the user typed it.
658        */
659       ZM_DEBUG (zm_dprintf ("Trailing gunk:\n"));
660       while ((c = (*getc) ()) > -1)
661         ;
662       ZM_DEBUG (zm_dprintf ("\n"));
663       /*
664        * Make a small delay to give terminal programs like minicom
665        * time to get control again after their file transfer program
666        * exits.
667        */
668       CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
669     }
670 }
671 
672 char *
673 xyzModem_error (int err)
674 {
675   switch (err)
676     {
677     case xyzModem_access:
678       return "Can't access file";
679       break;
680     case xyzModem_noZmodem:
681       return "Sorry, zModem not available yet";
682       break;
683     case xyzModem_timeout:
684       return "Timed out";
685       break;
686     case xyzModem_eof:
687       return "End of file";
688       break;
689     case xyzModem_cancel:
690       return "Cancelled";
691       break;
692     case xyzModem_frame:
693       return "Invalid framing";
694       break;
695     case xyzModem_cksum:
696       return "CRC/checksum error";
697       break;
698     case xyzModem_sequence:
699       return "Block sequence error";
700       break;
701     default:
702       return "Unknown error";
703       break;
704     }
705 }
706 
707 /*
708  * RedBoot interface
709  */
710