xref: /openbmc/u-boot/common/xyzModem.c (revision fabbeb33) 
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 #include <watchdog.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 /* Data & state local to the protocol */
43 static struct
44 {
45   int *__chan;
46   unsigned char pkt[1024], *bufp;
47   unsigned char blk, cblk, crc1, crc2;
48   unsigned char next_blk;	/* Expected block */
49   int len, mode, total_retries;
50   int total_SOH, total_STX, total_CAN;
51   bool crc_mode, at_eof, tx_ack;
52   unsigned long file_length, read_length;
53 } xyz;
54 
55 #define xyzModem_CHAR_TIMEOUT            2000	/* 2 seconds */
56 #define xyzModem_MAX_RETRIES             20
57 #define xyzModem_MAX_RETRIES_WITH_CRC    10
58 #define xyzModem_CAN_COUNT                3	/* Wait for 3 CAN before quitting */
59 
60 
61 typedef int cyg_int32;
62 static int
63 CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
64 {
65 
66   ulong now = get_timer(0);
67   WATCHDOG_RESET();
68   while (!tstc ())
69     {
70       if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
71         break;
72     }
73   if (tstc ())
74     {
75       *c = getc ();
76       return 1;
77     }
78   return 0;
79 }
80 
81 static void
82 CYGACC_COMM_IF_PUTC (char x, char y)
83 {
84   putc (y);
85 }
86 
87 /* Validate a hex character */
88 __inline__ static bool
89 _is_hex (char c)
90 {
91   return (((c >= '0') && (c <= '9')) ||
92 	  ((c >= 'A') && (c <= 'F')) || ((c >= 'a') && (c <= 'f')));
93 }
94 
95 /* Convert a single hex nibble */
96 __inline__ static int
97 _from_hex (char c)
98 {
99   int ret = 0;
100 
101   if ((c >= '0') && (c <= '9'))
102     {
103       ret = (c - '0');
104     }
105   else if ((c >= 'a') && (c <= 'f'))
106     {
107       ret = (c - 'a' + 0x0a);
108     }
109   else if ((c >= 'A') && (c <= 'F'))
110     {
111       ret = (c - 'A' + 0x0A);
112     }
113   return ret;
114 }
115 
116 /* Convert a character to lower case */
117 __inline__ static char
118 _tolower (char c)
119 {
120   if ((c >= 'A') && (c <= 'Z'))
121     {
122       c = (c - 'A') + 'a';
123     }
124   return c;
125 }
126 
127 /* Parse (scan) a number */
128 static bool
129 parse_num (char *s, unsigned long *val, char **es, char *delim)
130 {
131   bool first = true;
132   int radix = 10;
133   char c;
134   unsigned long result = 0;
135   int digit;
136 
137   while (*s == ' ')
138     s++;
139   while (*s)
140     {
141       if (first && (s[0] == '0') && (_tolower (s[1]) == 'x'))
142 	{
143 	  radix = 16;
144 	  s += 2;
145 	}
146       first = false;
147       c = *s++;
148       if (_is_hex (c) && ((digit = _from_hex (c)) < radix))
149 	{
150 	  /* Valid digit */
151 	  result = (result * radix) + digit;
152 	}
153       else
154 	{
155 	  if (delim != (char *) 0)
156 	    {
157 	      /* See if this character is one of the delimiters */
158 	      char *dp = delim;
159 	      while (*dp && (c != *dp))
160 		dp++;
161 	      if (*dp)
162 		break;		/* Found a good delimiter */
163 	    }
164 	  return false;		/* Malformatted number */
165 	}
166     }
167   *val = result;
168   if (es != (char **) 0)
169     {
170       *es = s;
171     }
172   return true;
173 }
174 
175 
176 #if defined(DEBUG) && !defined(CONFIG_USE_TINY_PRINTF)
177 /*
178  * Note: this debug setup works by storing the strings in a fixed buffer
179  */
180 static char zm_debug_buf[8192];
181 static char *zm_out = zm_debug_buf;
182 static char *zm_out_start = zm_debug_buf;
183 
184 static int
185 zm_dprintf(char *fmt, ...)
186 {
187 	int len;
188 	va_list args;
189 
190 	va_start(args, fmt);
191 	len = diag_vsprintf(zm_out, fmt, args);
192 	va_end(args);
193 	zm_out += len;
194 	return len;
195 }
196 
197 static void
198 zm_flush (void)
199 {
200   zm_out = zm_out_start;
201 }
202 
203 static void
204 zm_dump_buf (void *buf, int len)
205 {
206 
207 }
208 
209 static unsigned char zm_buf[2048];
210 static unsigned char *zm_bp;
211 
212 static void
213 zm_new (void)
214 {
215   zm_bp = zm_buf;
216 }
217 
218 static void
219 zm_save (unsigned char c)
220 {
221   *zm_bp++ = c;
222 }
223 
224 static void
225 zm_dump (int line)
226 {
227   zm_dprintf ("Packet at line: %d\n", line);
228   zm_dump_buf (zm_buf, zm_bp - zm_buf);
229 }
230 
231 #define ZM_DEBUG(x) x
232 #else
233 #define ZM_DEBUG(x)
234 #endif
235 
236 /* Wait for the line to go idle */
237 static void
238 xyzModem_flush (void)
239 {
240   int res;
241   char c;
242   while (true)
243     {
244       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
245       if (!res)
246 	return;
247     }
248 }
249 
250 static int
251 xyzModem_get_hdr (void)
252 {
253   char c;
254   int res;
255   bool hdr_found = false;
256   int i, can_total, hdr_chars;
257   unsigned short cksum;
258 
259   ZM_DEBUG (zm_new ());
260   /* Find the start of a header */
261   can_total = 0;
262   hdr_chars = 0;
263 
264   if (xyz.tx_ack)
265     {
266       CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
267       xyz.tx_ack = false;
268     }
269   while (!hdr_found)
270     {
271       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
272       ZM_DEBUG (zm_save (c));
273       if (res)
274 	{
275 	  hdr_chars++;
276 	  switch (c)
277 	    {
278 	    case SOH:
279 	      xyz.total_SOH++;
280 	    case STX:
281 	      if (c == STX)
282 		xyz.total_STX++;
283 	      hdr_found = true;
284 	      break;
285 	    case CAN:
286 	      xyz.total_CAN++;
287 	      ZM_DEBUG (zm_dump (__LINE__));
288 	      if (++can_total == xyzModem_CAN_COUNT)
289 		{
290 		  return xyzModem_cancel;
291 		}
292 	      else
293 		{
294 		  /* Wait for multiple CAN to avoid early quits */
295 		  break;
296 		}
297 	    case EOT:
298 	      /* EOT only supported if no noise */
299 	      if (hdr_chars == 1)
300 		{
301 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
302 		  ZM_DEBUG (zm_dprintf ("ACK on EOT #%d\n", __LINE__));
303 		  ZM_DEBUG (zm_dump (__LINE__));
304 		  return xyzModem_eof;
305 		}
306 	    default:
307 	      /* Ignore, waiting for start of header */
308 	      ;
309 	    }
310 	}
311       else
312 	{
313 	  /* Data stream timed out */
314 	  xyzModem_flush ();	/* Toss any current input */
315 	  ZM_DEBUG (zm_dump (__LINE__));
316 	  CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
317 	  return xyzModem_timeout;
318 	}
319     }
320 
321   /* Header found, now read the data */
322   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.blk);
323   ZM_DEBUG (zm_save (xyz.blk));
324   if (!res)
325     {
326       ZM_DEBUG (zm_dump (__LINE__));
327       return xyzModem_timeout;
328     }
329   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.cblk);
330   ZM_DEBUG (zm_save (xyz.cblk));
331   if (!res)
332     {
333       ZM_DEBUG (zm_dump (__LINE__));
334       return xyzModem_timeout;
335     }
336   xyz.len = (c == SOH) ? 128 : 1024;
337   xyz.bufp = xyz.pkt;
338   for (i = 0; i < xyz.len; i++)
339     {
340       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
341       ZM_DEBUG (zm_save (c));
342       if (res)
343 	{
344 	  xyz.pkt[i] = c;
345 	}
346       else
347 	{
348 	  ZM_DEBUG (zm_dump (__LINE__));
349 	  return xyzModem_timeout;
350 	}
351     }
352   res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc1);
353   ZM_DEBUG (zm_save (xyz.crc1));
354   if (!res)
355     {
356       ZM_DEBUG (zm_dump (__LINE__));
357       return xyzModem_timeout;
358     }
359   if (xyz.crc_mode)
360     {
361       res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc2);
362       ZM_DEBUG (zm_save (xyz.crc2));
363       if (!res)
364 	{
365 	  ZM_DEBUG (zm_dump (__LINE__));
366 	  return xyzModem_timeout;
367 	}
368     }
369   ZM_DEBUG (zm_dump (__LINE__));
370   /* Validate the message */
371   if ((xyz.blk ^ xyz.cblk) != (unsigned char) 0xFF)
372     {
373       ZM_DEBUG (zm_dprintf
374 		("Framing error - blk: %x/%x/%x\n", xyz.blk, xyz.cblk,
375 		 (xyz.blk ^ xyz.cblk)));
376       ZM_DEBUG (zm_dump_buf (xyz.pkt, xyz.len));
377       xyzModem_flush ();
378       return xyzModem_frame;
379     }
380   /* Verify checksum/CRC */
381   if (xyz.crc_mode)
382     {
383       cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
384       if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
385 	{
386 	  ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
387 				xyz.crc1, xyz.crc2, cksum & 0xFFFF));
388 	  return xyzModem_cksum;
389 	}
390     }
391   else
392     {
393       cksum = 0;
394       for (i = 0; i < xyz.len; i++)
395 	{
396 	  cksum += xyz.pkt[i];
397 	}
398       if (xyz.crc1 != (cksum & 0xFF))
399 	{
400 	  ZM_DEBUG (zm_dprintf
401 		    ("Checksum error - recvd: %x, computed: %x\n", xyz.crc1,
402 		     cksum & 0xFF));
403 	  return xyzModem_cksum;
404 	}
405     }
406   /* If we get here, the message passes [structural] muster */
407   return 0;
408 }
409 
410 int
411 xyzModem_stream_open (connection_info_t * info, int *err)
412 {
413   int stat = 0;
414   int retries = xyzModem_MAX_RETRIES;
415   int crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;
416 
417 /*    ZM_DEBUG(zm_out = zm_out_start); */
418 #ifdef xyzModem_zmodem
419   if (info->mode == xyzModem_zmodem)
420     {
421       *err = xyzModem_noZmodem;
422       return -1;
423     }
424 #endif
425 
426 /* TODO: CHECK ! */
427   int dummy = 0;
428   xyz.__chan = &dummy;
429   xyz.len = 0;
430   xyz.crc_mode = true;
431   xyz.at_eof = false;
432   xyz.tx_ack = false;
433   xyz.mode = info->mode;
434   xyz.total_retries = 0;
435   xyz.total_SOH = 0;
436   xyz.total_STX = 0;
437   xyz.total_CAN = 0;
438   xyz.read_length = 0;
439   xyz.file_length = 0;
440 
441   CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
442 
443   if (xyz.mode == xyzModem_xmodem)
444     {
445       /* X-modem doesn't have an information header - exit here */
446       xyz.next_blk = 1;
447       return 0;
448     }
449 
450   while (retries-- > 0)
451     {
452       stat = xyzModem_get_hdr ();
453       if (stat == 0)
454 	{
455 	  /* Y-modem file information header */
456 	  if (xyz.blk == 0)
457 	    {
458 	      /* skip filename */
459 	      while (*xyz.bufp++);
460 	      /* get the length */
461 	      parse_num ((char *) xyz.bufp, &xyz.file_length, NULL, " ");
462 	      /* The rest of the file name data block quietly discarded */
463 	      xyz.tx_ack = true;
464 	    }
465 	  xyz.next_blk = 1;
466 	  xyz.len = 0;
467 	  return 0;
468 	}
469       else if (stat == xyzModem_timeout)
470 	{
471 	  if (--crc_retries <= 0)
472 	    xyz.crc_mode = false;
473 	  CYGACC_CALL_IF_DELAY_US (5 * 100000);	/* Extra delay for startup */
474 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
475 	  xyz.total_retries++;
476 	  ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
477 	}
478       if (stat == xyzModem_cancel)
479 	{
480 	  break;
481 	}
482     }
483   *err = stat;
484   ZM_DEBUG (zm_flush ());
485   return -1;
486 }
487 
488 int
489 xyzModem_stream_read (char *buf, int size, int *err)
490 {
491   int stat, total, len;
492   int retries;
493 
494   total = 0;
495   stat = xyzModem_cancel;
496   /* Try and get 'size' bytes into the buffer */
497   while (!xyz.at_eof && (size > 0))
498     {
499       if (xyz.len == 0)
500 	{
501 	  retries = xyzModem_MAX_RETRIES;
502 	  while (retries-- > 0)
503 	    {
504 	      stat = xyzModem_get_hdr ();
505 	      if (stat == 0)
506 		{
507 		  if (xyz.blk == xyz.next_blk)
508 		    {
509 		      xyz.tx_ack = true;
510 		      ZM_DEBUG (zm_dprintf
511 				("ACK block %d (%d)\n", xyz.blk, __LINE__));
512 		      xyz.next_blk = (xyz.next_blk + 1) & 0xFF;
513 
514 		      if (xyz.mode == xyzModem_xmodem || xyz.file_length == 0)
515 			{
516 			  /* Data blocks can be padded with ^Z (EOF) characters */
517 			  /* This code tries to detect and remove them */
518 			  if ((xyz.bufp[xyz.len - 1] == EOF) &&
519 			      (xyz.bufp[xyz.len - 2] == EOF) &&
520 			      (xyz.bufp[xyz.len - 3] == EOF))
521 			    {
522 			      while (xyz.len
523 				     && (xyz.bufp[xyz.len - 1] == EOF))
524 				{
525 				  xyz.len--;
526 				}
527 			    }
528 			}
529 
530 		      /*
531 		       * See if accumulated length exceeds that of the file.
532 		       * If so, reduce size (i.e., cut out pad bytes)
533 		       * Only do this for Y-modem (and Z-modem should it ever
534 		       * be supported since it can fall back to Y-modem mode).
535 		       */
536 		      if (xyz.mode != xyzModem_xmodem && 0 != xyz.file_length)
537 			{
538 			  xyz.read_length += xyz.len;
539 			  if (xyz.read_length > xyz.file_length)
540 			    {
541 			      xyz.len -= (xyz.read_length - xyz.file_length);
542 			    }
543 			}
544 		      break;
545 		    }
546 		  else if (xyz.blk == ((xyz.next_blk - 1) & 0xFF))
547 		    {
548 		      /* Just re-ACK this so sender will get on with it */
549 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
550 		      continue;	/* Need new header */
551 		    }
552 		  else
553 		    {
554 		      stat = xyzModem_sequence;
555 		    }
556 		}
557 	      if (stat == xyzModem_cancel)
558 		{
559 		  break;
560 		}
561 	      if (stat == xyzModem_eof)
562 		{
563 		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
564 		  ZM_DEBUG (zm_dprintf ("ACK (%d)\n", __LINE__));
565 		  if (xyz.mode == xyzModem_ymodem)
566 		    {
567 		      CYGACC_COMM_IF_PUTC (*xyz.__chan,
568 					   (xyz.crc_mode ? 'C' : NAK));
569 		      xyz.total_retries++;
570 		      ZM_DEBUG (zm_dprintf ("Reading Final Header\n"));
571 		      stat = xyzModem_get_hdr ();
572 		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
573 		      ZM_DEBUG (zm_dprintf ("FINAL ACK (%d)\n", __LINE__));
574 		    }
575 		  xyz.at_eof = true;
576 		  break;
577 		}
578 	      CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
579 	      xyz.total_retries++;
580 	      ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
581 	    }
582 	  if (stat < 0)
583 	    {
584 	      *err = stat;
585 	      xyz.len = -1;
586 	      return total;
587 	    }
588 	}
589       /* Don't "read" data from the EOF protocol package */
590       if (!xyz.at_eof)
591 	{
592 	  len = xyz.len;
593 	  if (size < len)
594 	    len = size;
595 	  memcpy (buf, xyz.bufp, len);
596 	  size -= len;
597 	  buf += len;
598 	  total += len;
599 	  xyz.len -= len;
600 	  xyz.bufp += len;
601 	}
602     }
603   return total;
604 }
605 
606 void
607 xyzModem_stream_close (int *err)
608 {
609   diag_printf
610     ("xyzModem - %s mode, %d(SOH)/%d(STX)/%d(CAN) packets, %d retries\n",
611      xyz.crc_mode ? "CRC" : "Cksum", xyz.total_SOH, xyz.total_STX,
612      xyz.total_CAN, xyz.total_retries);
613   ZM_DEBUG (zm_flush ());
614 }
615 
616 /* Need to be able to clean out the input buffer, so have to take the */
617 /* getc */
618 void
619 xyzModem_stream_terminate (bool abort, int (*getc) (void))
620 {
621   int c;
622 
623   if (abort)
624     {
625       ZM_DEBUG (zm_dprintf ("!!!! TRANSFER ABORT !!!!\n"));
626       switch (xyz.mode)
627 	{
628 	case xyzModem_xmodem:
629 	case xyzModem_ymodem:
630 	  /* The X/YMODEM Spec seems to suggest that multiple CAN followed by an equal */
631 	  /* number of Backspaces is a friendly way to get the other end to abort. */
632 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
633 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
634 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
635 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
636 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
637 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
638 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
639 	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
640 	  /* Now consume the rest of what's waiting on the line. */
641 	  ZM_DEBUG (zm_dprintf ("Flushing serial line.\n"));
642 	  xyzModem_flush ();
643 	  xyz.at_eof = true;
644 	  break;
645 #ifdef xyzModem_zmodem
646 	case xyzModem_zmodem:
647 	  /* Might support it some day I suppose. */
648 #endif
649 	  break;
650 	}
651     }
652   else
653     {
654       ZM_DEBUG (zm_dprintf ("Engaging cleanup mode...\n"));
655       /*
656        * Consume any trailing crap left in the inbuffer from
657        * previous received blocks. Since very few files are an exact multiple
658        * of the transfer block size, there will almost always be some gunk here.
659        * If we don't eat it now, RedBoot will think the user typed it.
660        */
661       ZM_DEBUG (zm_dprintf ("Trailing gunk:\n"));
662       while ((c = (*getc) ()) > -1)
663         ;
664       ZM_DEBUG (zm_dprintf ("\n"));
665       /*
666        * Make a small delay to give terminal programs like minicom
667        * time to get control again after their file transfer program
668        * exits.
669        */
670       CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
671     }
672 }
673 
674 char *
675 xyzModem_error (int err)
676 {
677   switch (err)
678     {
679     case xyzModem_access:
680       return "Can't access file";
681       break;
682     case xyzModem_noZmodem:
683       return "Sorry, zModem not available yet";
684       break;
685     case xyzModem_timeout:
686       return "Timed out";
687       break;
688     case xyzModem_eof:
689       return "End of file";
690       break;
691     case xyzModem_cancel:
692       return "Cancelled";
693       break;
694     case xyzModem_frame:
695       return "Invalid framing";
696       break;
697     case xyzModem_cksum:
698       return "CRC/checksum error";
699       break;
700     case xyzModem_sequence:
701       return "Block sequence error";
702       break;
703     default:
704       return "Unknown error";
705       break;
706     }
707 }
708 
709 /*
710  * RedBoot interface
711  */
712