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
CYGACC_COMM_IF_GETC_TIMEOUT(char chan,char * c)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
CYGACC_COMM_IF_PUTC(char x,char y)82 CYGACC_COMM_IF_PUTC (char x, char y)
83 {
84 putc (y);
85 }
86
87 /* Validate a hex character */
88 __inline__ static bool
_is_hex(char c)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
_from_hex(char c)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
_tolower(char c)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
parse_num(char * s,unsigned long * val,char ** es,char * delim)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) && !CONFIG_IS_ENABLED(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
zm_dprintf(char * fmt,...)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
zm_flush(void)198 zm_flush (void)
199 {
200 zm_out = zm_out_start;
201 }
202
203 static void
zm_dump_buf(void * buf,int len)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
zm_new(void)213 zm_new (void)
214 {
215 zm_bp = zm_buf;
216 }
217
218 static void
zm_save(unsigned char c)219 zm_save (unsigned char c)
220 {
221 *zm_bp++ = c;
222 }
223
224 static void
zm_dump(int line)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
xyzModem_flush(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
xyzModem_get_hdr(void)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
xyzModem_stream_open(connection_info_t * info,int * err)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
xyzModem_stream_read(char * buf,int size,int * err)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
xyzModem_stream_close(int * err)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
xyzModem_stream_terminate(bool abort,int (* getc)(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 *
xyzModem_error(int err)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