Update this to the latest version from Steve Gerakines. This is an easy
drop-in for me and looks substantailly neater than the previous version, so I'll give the floppy tape users a break (but just this once :).
This commit is contained in:
jkh
parent
5b9b00defa
commit
b95edccba4
@ -1,7 +1,8 @@
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# $Id$
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# $Id: Makefile,v 1.2 1994/02/07 08:40:16 rgrimes Exp $
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PROG= ft
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MAN8= ft.8
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SRCS= ft.c ftecc.c
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COPTS= -O2 -finline-functions -funroll-loops -fexpensive-optimizations
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.include <bsd.prog.mk>
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219
sbin/ft/ft.c
219
sbin/ft/ft.c
@ -1,5 +1,5 @@
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/*
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* Copyright (c) 1993 Steve Gerakines
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* Copyright (c) 1993, 1994 Steve Gerakines
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*
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* This is freely redistributable software. You may do anything you
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* wish with it, so long as the above notice stays intact.
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@ -18,6 +18,10 @@
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*
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* ft.c - simple floppy tape filter
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*
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* 06/07/94 v1.0 ++sg
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* Added support for tape retension. Added retries for ecc failures.
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* Moved to release.
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*
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* 01/28/94 v0.3b (Jim Babb)
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* Fixed bug when all sectors in a segment are marked bad.
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*
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@ -27,7 +31,7 @@
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* 09/02/93 v0.2 pl01
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* Initial revision.
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*
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* usage: ftfilt [ -f tape ] [ description ]
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* usage: ft [ -f tape ] [ description ]
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*/
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#include <stdio.h>
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@ -51,6 +55,7 @@ int tvlast; /* TRUE if last volume in set */
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long tvsize = 0; /* tape volume size in bytes */
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long tvtime = NULL; /* tape change time */
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char *tvnote = ""; /* tape note */
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int doretension = 0; /* TRUE if we should retension tape */
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/* Lookup the badmap for a given track and segment. */
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#define BADMAP(t,s) hptr->qh_badmap[(t)*geo.g_segtrk+(s)]
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@ -62,45 +67,22 @@ char *tvnote = ""; /* tape note */
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#define equal(s1,s2) (strcmp(s1, s2) == 0)
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/* Entry */
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main(int argc, char *argv[])
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/*
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* Print tape usage and then leave.
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*/
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void
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usage(void)
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{
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int r, s;
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char *tape, *getenv();
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if (argc > 2 && (equal(argv[1], "-t") || equal(argv[1], "-f"))) {
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argc -= 2;
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tape = argv[2];
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argv += 2;
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} else
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if ((tape = getenv("TAPE")) == NULL)
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tape = DEFQIC;
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if (argc > 1) {
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tvnote = argv[1];
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if (strlen(tvnote) > 18) argv[1][18] = '\0';
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}
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/* Open the tape device */
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if ((tfd = open(tape, 2)) < 0) {
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perror(tape);
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exit(1);
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}
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if (!isatty(0))
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do_write();
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else if (!isatty(1))
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do_read();
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else
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do_getname();
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close(tfd);
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exit(0);
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fprintf(stderr, "usage: ft [ -r ] [ -f device ] [ \"description\" ]\n");
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exit(1);
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}
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/* Check status of tape drive */
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int check_stat(int fd, int wr)
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/*
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* Check status of tape drive
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*/
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int
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check_stat(int fd, int wr)
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{
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int r, s;
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int sawit = 0;
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@ -138,8 +120,11 @@ int check_stat(int fd, int wr)
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}
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ULONG qtimeval(time_t t)
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/*
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* Convert time_t value to QIC time value.
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*/
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ULONG
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qtimeval(time_t t)
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{
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struct tm *tp;
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ULONG r;
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@ -154,8 +139,12 @@ ULONG qtimeval(time_t t)
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return(r);
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}
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/* Return tm struct from QIC date format. */
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struct tm *qtime(UCHAR *qt)
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/*
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* Return tm struct from QIC date format.
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*/
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struct tm *
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qtime(UCHAR *qt)
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{
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ULONG *vp = (ULONG *)qt;
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struct tm t;
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@ -178,7 +167,10 @@ struct tm *qtime(UCHAR *qt)
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return(localtime(&tv));
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}
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/* Return a string, zero terminated */
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/*
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* Return a string, zero terminated.
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*/
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char *qstr(char *str, int nchar)
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{
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static char tstr[256];
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@ -187,7 +179,11 @@ char *qstr(char *str, int nchar)
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return(tstr);
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}
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/* Read header from tape */
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/*
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* Read header from tape
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*/
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int
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get_header(int fd)
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{
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int r, sn, bytes;
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@ -238,6 +234,9 @@ get_header(int fd)
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}
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/*
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* Open /dev/tty and ask for next volume.
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*/
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ask_vol(int vn)
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{
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FILE *inp;
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@ -255,21 +254,26 @@ ask_vol(int vn)
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}
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/* Return the name of the tape only. */
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do_getname()
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/*
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* Return the name of the tape only.
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*/
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void
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do_getname(void)
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{
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if (check_stat(tfd, 0)) exit(1);
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if (get_header(tfd)) exit(1);
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fprintf(stderr, "\"%s\" - %s",
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qstr(hptr->qh_tname,44), asctime(qtime(hptr->qh_chgdate)));
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ioctl(tfd, QIOREWIND);
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}
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/* Extract data from tape to stdout */
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do_read()
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/*
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* Extract data from tape to stdout.
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*/
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void
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do_read(void)
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{
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int sno, vno, sbytes, r;
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int sno, vno, sbytes, r, eccfails;
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long curpos;
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char *hname;
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QIC_Segment s;
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@ -281,6 +285,13 @@ do_read()
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ask_vol(vno);
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continue;
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}
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if (doretension) {
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ioctl(tfd, QIOBOT);
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ioctl(tfd, QIOEOT);
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ioctl(tfd, QIOBOT);
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}
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if (get_header(tfd)) {
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ask_vol(vno);
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continue;
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@ -303,36 +314,50 @@ do_read()
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/* Process this volume */
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curpos = 0;
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for (sno = hptr->qh_first; tvsize > 0; sno++) {
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eccfails = 0;
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sno = hptr->qh_first;
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while (tvsize > 0) {
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s.sg_trk = sno / geo.g_segtrk;
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s.sg_seg = sno % geo.g_segtrk;
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s.sg_badmap = BADMAP(s.sg_trk,s.sg_seg);
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sbytes = sect_bytes(s.sg_badmap) - QCV_ECCSIZE;
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s.sg_data = (UCHAR *)&buff[0];
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/* skip segments with *all* sectors flagged as bad */
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if (sbytes > 0) {
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if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD");
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r = check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap);
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if (r) fprintf(stderr, "** warning: ecc failed at byte %ld\n",
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curpos);
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if (tvsize < sbytes) sbytes = tvsize;
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write(1, s.sg_data, sbytes);
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tvsize -= sbytes;
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curpos += sbytes;
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if (sbytes <= 0) {
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sno++;
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continue;
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}
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if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD");
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if (check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap)) {
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if (++eccfails <= 5) {
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fprintf(stderr,
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"ft: retry %d at segment %d byte %ld\n",
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eccfails, sno, curpos);
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continue;
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} else
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fprintf(stderr,
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"ft: *** ecc failure in segment %d at byte %ld\n",
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sno, curpos);
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}
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if (tvsize < sbytes) sbytes = tvsize;
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write(1, s.sg_data, sbytes);
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tvsize -= sbytes;
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curpos += sbytes;
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sno++;
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eccfails = 0;
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}
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if (tvlast) break;
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ioctl(tfd, QIOREWIND);
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ask_vol(++vno);
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}
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ioctl(tfd, QIOREWIND);
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return(0);
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}
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/* Dump data from stdin to tape */
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do_write()
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/*
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* Dump data from stdin to tape.
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*/
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void
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do_write(void)
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{
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int sno, vno, amt, sbytes;
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int c, maxseg, r;
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@ -348,6 +373,13 @@ do_write()
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ask_vol(vno);
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continue;
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}
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if (doretension) {
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ioctl(tfd, QIOBOT);
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ioctl(tfd, QIOEOT);
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ioctl(tfd, QIOBOT);
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}
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if (get_header(tfd)) {
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ask_vol(vno);
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continue;
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@ -376,6 +408,7 @@ do_write()
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break;
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}
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}
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/* skip the segment if *all* sectors are flagged as bad */
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if (amt) {
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if (amt < sbytes)
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@ -410,7 +443,7 @@ do_write()
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if (ioctl(tfd, QIOWRITE, &s) < 0) {
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perror("QIOWRITE");
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exit(1);
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}
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}
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}
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if (dhsn >= 0) {
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s.sg_trk = dhsn / geo.g_segtrk;
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@ -428,5 +461,57 @@ do_write()
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if (tvlast) break;
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ask_vol(++vno);
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}
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return(0);
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}
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/*
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* Entry.
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*/
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void
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main(int argc, char *argv[])
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{
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int r, s, i;
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char *tape, *getenv();
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/* Get device from environment, command line will override. */
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if ((tape = getenv("TAPE")) == NULL) tape = DEFQIC;
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/* Process args. */
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for (i = 1; i < argc; i++) {
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if (argv[i][0] != '-') break;
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switch (argv[i][1]) {
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case 'f':
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case 't':
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if (i == (argc - 1)) usage();
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tape = argv[++i];
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break;
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case 'r':
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doretension = 1;
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break;
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default:
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usage();
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}
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}
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if (i < (argc - 1)) usage();
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if (i < argc) {
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tvnote = argv[i];
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if (strlen(tvnote) > 18) argv[i][18] = '\0';
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}
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/* Open the tape device */
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if ((tfd = open(tape, 2)) < 0) {
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perror(tape);
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exit(1);
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}
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if (!isatty(0))
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do_write();
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else if (!isatty(1))
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do_read();
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else
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do_getname();
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close(tfd);
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exit(0);
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}
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128
sbin/ft/ftecc.c
128
sbin/ft/ftecc.c
@ -17,6 +17,11 @@
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* ftecc.c - QIC-40/80 Reed-Solomon error correction
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* 05/30/94 v1.0 ++sg
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* Did some minor optimization. The multiply by 0xc0 was a dog so it
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* was replaced with a table lookup. Fixed a couple of places where
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* bad sectors could go unnoticed. Moved to release.
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*
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* 03/22/94 v0.4
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* Major re-write. It can handle everything required by QIC now.
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*
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@ -111,6 +116,45 @@ static UCHAR alpha_log[] = {
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};
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/*
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* Multiplication table for 0xc0.
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*/
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static UCHAR mult_c0[] = {
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0x00, 0xc0, 0x07, 0xc7, 0x0e, 0xce, 0x09, 0xc9,
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0x1c, 0xdc, 0x1b, 0xdb, 0x12, 0xd2, 0x15, 0xd5,
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0x38, 0xf8, 0x3f, 0xff, 0x36, 0xf6, 0x31, 0xf1,
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0x24, 0xe4, 0x23, 0xe3, 0x2a, 0xea, 0x2d, 0xed,
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0x70, 0xb0, 0x77, 0xb7, 0x7e, 0xbe, 0x79, 0xb9,
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0x6c, 0xac, 0x6b, 0xab, 0x62, 0xa2, 0x65, 0xa5,
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0x48, 0x88, 0x4f, 0x8f, 0x46, 0x86, 0x41, 0x81,
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0x54, 0x94, 0x53, 0x93, 0x5a, 0x9a, 0x5d, 0x9d,
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0xe0, 0x20, 0xe7, 0x27, 0xee, 0x2e, 0xe9, 0x29,
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0xfc, 0x3c, 0xfb, 0x3b, 0xf2, 0x32, 0xf5, 0x35,
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0xd8, 0x18, 0xdf, 0x1f, 0xd6, 0x16, 0xd1, 0x11,
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0xc4, 0x04, 0xc3, 0x03, 0xca, 0x0a, 0xcd, 0x0d,
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0x90, 0x50, 0x97, 0x57, 0x9e, 0x5e, 0x99, 0x59,
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0x8c, 0x4c, 0x8b, 0x4b, 0x82, 0x42, 0x85, 0x45,
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0xa8, 0x68, 0xaf, 0x6f, 0xa6, 0x66, 0xa1, 0x61,
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0xb4, 0x74, 0xb3, 0x73, 0xba, 0x7a, 0xbd, 0x7d,
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0x47, 0x87, 0x40, 0x80, 0x49, 0x89, 0x4e, 0x8e,
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0x5b, 0x9b, 0x5c, 0x9c, 0x55, 0x95, 0x52, 0x92,
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0x7f, 0xbf, 0x78, 0xb8, 0x71, 0xb1, 0x76, 0xb6,
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0x63, 0xa3, 0x64, 0xa4, 0x6d, 0xad, 0x6a, 0xaa,
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0x37, 0xf7, 0x30, 0xf0, 0x39, 0xf9, 0x3e, 0xfe,
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0x2b, 0xeb, 0x2c, 0xec, 0x25, 0xe5, 0x22, 0xe2,
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0x0f, 0xcf, 0x08, 0xc8, 0x01, 0xc1, 0x06, 0xc6,
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0x13, 0xd3, 0x14, 0xd4, 0x1d, 0xdd, 0x1a, 0xda,
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0xa7, 0x67, 0xa0, 0x60, 0xa9, 0x69, 0xae, 0x6e,
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0xbb, 0x7b, 0xbc, 0x7c, 0xb5, 0x75, 0xb2, 0x72,
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0x9f, 0x5f, 0x98, 0x58, 0x91, 0x51, 0x96, 0x56,
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0x83, 0x43, 0x84, 0x44, 0x8d, 0x4d, 0x8a, 0x4a,
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0xd7, 0x17, 0xd0, 0x10, 0xd9, 0x19, 0xde, 0x1e,
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0xcb, 0x0b, 0xcc, 0x0c, 0xc5, 0x05, 0xc2, 0x02,
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0xef, 0x2f, 0xe8, 0x28, 0xe1, 0x21, 0xe6, 0x26,
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0xf3, 0x33, 0xf4, 0x34, 0xfd, 0x3d, 0xfa, 0x3a
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};
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/*
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* Return number of sectors available in a segment.
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*/
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@ -142,29 +186,37 @@ sect_bytes(ULONG badmap)
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/*
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* Multiply two numbers in the field.
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*/
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static UCHAR
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static inline UCHAR
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multiply(UCHAR a, UCHAR b)
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{
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int tmp;
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if (!a || !b) return(0);
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return(alpha_power[(alpha_log[a] + alpha_log[b]) % 255]);
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tmp = alpha_log[a] + alpha_log[b];
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if (tmp > 254) tmp -= 255;
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return(alpha_power[tmp]);
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}
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|
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/*
|
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* Multiply by an exponent.
|
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*/
|
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static UCHAR
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static inline UCHAR
|
||||
multiply_out(UCHAR a, int b)
|
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{
|
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int tmp;
|
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|
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if (!a) return(0);
|
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return(alpha_power[(alpha_log[a] + b) % 255]);
|
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tmp = alpha_log[a] + b;
|
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if (tmp > 254) tmp -= 255;
|
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return(alpha_power[tmp]);
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}
|
||||
|
||||
|
||||
/*
|
||||
* Divide two numbers.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
divide(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp;
|
||||
@ -179,7 +231,7 @@ divide(UCHAR a, UCHAR b)
|
||||
/*
|
||||
* Divide using exponent.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
divide_out(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp;
|
||||
@ -194,13 +246,13 @@ divide_out(UCHAR a, UCHAR b)
|
||||
/*
|
||||
* This returns the value z^{a-b}.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
z_of_ab(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp = a - b;
|
||||
|
||||
if (tmp < 0) tmp += 255;
|
||||
return(alpha_power[tmp % 255]);
|
||||
return(alpha_power[tmp]);
|
||||
}
|
||||
|
||||
|
||||
@ -208,12 +260,13 @@ z_of_ab(UCHAR a, UCHAR b)
|
||||
* Calculate the inverse matrix for two or three errors. Returns 0
|
||||
* if there is no inverse or 1 if successful.
|
||||
*/
|
||||
static int
|
||||
static inline int
|
||||
calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
{
|
||||
/* First some variables to remember some of the results. */
|
||||
UCHAR z20, z10, z21, z12, z01, z02;
|
||||
UCHAR i0, i1, i2;
|
||||
UCHAR iv0, iv1, iv2;
|
||||
|
||||
if (nerrs < 2) return(1);
|
||||
if (nerrs > 3) return(0);
|
||||
@ -243,21 +296,21 @@ calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
if (!inv->log_denom) return(0);
|
||||
inv->log_denom = 255 - alpha_log[inv->log_denom];
|
||||
|
||||
inv->zs[0][0] = multiply_out(alpha_power[i1] ^ alpha_power[i2],
|
||||
inv->log_denom);
|
||||
iv0 = alpha_power[255 - i0];
|
||||
iv1 = alpha_power[255 - i1];
|
||||
iv2 = alpha_power[255 - i2];
|
||||
i0 = alpha_power[i0];
|
||||
i1 = alpha_power[i1];
|
||||
i2 = alpha_power[i2];
|
||||
inv->zs[0][0] = multiply_out(i1 ^ i2, inv->log_denom);
|
||||
inv->zs[0][1] = multiply_out(z21 ^ z12, inv->log_denom);
|
||||
inv->zs[0][2] = multiply_out(alpha_power[255-i1] ^ alpha_power[255-i2],
|
||||
inv->log_denom);
|
||||
inv->zs[1][0] = multiply_out(alpha_power[i0] ^ alpha_power[i2],
|
||||
inv->log_denom);
|
||||
inv->zs[0][2] = multiply_out(iv1 ^ iv2, inv->log_denom);
|
||||
inv->zs[1][0] = multiply_out(i0 ^ i2, inv->log_denom);
|
||||
inv->zs[1][1] = multiply_out(z20 ^ z02, inv->log_denom);
|
||||
inv->zs[1][2] = multiply_out(alpha_power[255-i0] ^ alpha_power[255-i2],
|
||||
inv->log_denom);
|
||||
inv->zs[2][0] = multiply_out(alpha_power[i0] ^ alpha_power[i1],
|
||||
inv->log_denom);
|
||||
inv->zs[1][2] = multiply_out(iv0 ^ iv2, inv->log_denom);
|
||||
inv->zs[2][0] = multiply_out(i0 ^ i1, inv->log_denom);
|
||||
inv->zs[2][1] = multiply_out(z10 ^ z01, inv->log_denom);
|
||||
inv->zs[2][2] = multiply_out(alpha_power[255-i0] ^ alpha_power[255-i1],
|
||||
inv->log_denom);
|
||||
inv->zs[2][2] = multiply_out(iv0 ^ iv1, inv->log_denom);
|
||||
}
|
||||
return(1);
|
||||
}
|
||||
@ -266,7 +319,7 @@ calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
/*
|
||||
* Determine the error magnitudes for a given matrix and syndromes.
|
||||
*/
|
||||
static void
|
||||
static inline void
|
||||
determine(int nerrs, struct inv_mat *inv, UCHAR *ss, UCHAR *es)
|
||||
{
|
||||
UCHAR tmp;
|
||||
@ -283,21 +336,22 @@ determine(int nerrs, struct inv_mat *inv, UCHAR *ss, UCHAR *es)
|
||||
/*
|
||||
* Compute the 3 syndrome values.
|
||||
*/
|
||||
static int
|
||||
static inline int
|
||||
compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss)
|
||||
{
|
||||
UCHAR r0, r1, r2, t1, t2;
|
||||
UCHAR *rptr;
|
||||
int row;
|
||||
|
||||
rptr = &data[col];
|
||||
rptr = data + col;
|
||||
data += nblks << 10;
|
||||
r0 = r1 = r2 = 0;
|
||||
for (row = 0; row < nblks; row++, rptr += QCV_BLKSIZE) {
|
||||
while (rptr < data) {
|
||||
t1 = *rptr ^ r0;
|
||||
t2 = multiply(0xc0, t1);
|
||||
t2 = mult_c0[t1];
|
||||
r0 = t2 ^ r1;
|
||||
r1 = t2 ^ r2;
|
||||
r2 = t1;
|
||||
rptr += QCV_BLKSIZE;
|
||||
}
|
||||
if (r0 || r1 || r2) {
|
||||
ss[0] = divide_out(r0 ^ divide_out(r1 ^ divide_out(r2, 1), 1), nblks);
|
||||
@ -315,24 +369,28 @@ compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss)
|
||||
int
|
||||
set_parity (UCHAR *data, ULONG badmap)
|
||||
{
|
||||
int col, row, max;
|
||||
UCHAR r0, r1, r2, t1, t2;
|
||||
UCHAR *rptr;
|
||||
int max, row, col;
|
||||
|
||||
max = sect_count(badmap) - 3;
|
||||
for (col = 0; col < QCV_BLKSIZE; col++, data++) {
|
||||
col = QCV_BLKSIZE;
|
||||
while (col--) {
|
||||
rptr = data;
|
||||
r0 = r1 = r2 = 0;
|
||||
for (row = 0; row < max; row++, rptr += QCV_BLKSIZE) {
|
||||
row = max;
|
||||
while (row--) {
|
||||
t1 = *rptr ^ r0;
|
||||
t2 = multiply(0xc0, t1);
|
||||
t2 = mult_c0[t1];
|
||||
r0 = t2 ^ r1;
|
||||
r1 = t2 ^ r2;
|
||||
r2 = t1;
|
||||
rptr += QCV_BLKSIZE;
|
||||
}
|
||||
*rptr = r0; rptr += QCV_BLKSIZE;
|
||||
*rptr = r1; rptr += QCV_BLKSIZE;
|
||||
*rptr = r2;
|
||||
data++;
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
@ -359,8 +417,8 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
if (crcmap) {
|
||||
for (i = 0; i < nblks; i++) {
|
||||
if (crcmap & (1 << i)) {
|
||||
if (crcerrs == 3) return(1);
|
||||
eblk[crcerrs++] = i;
|
||||
if (crcerrs >= 3) break;
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -380,7 +438,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
eblk[crcerrs] = alpha_log[divide(ss[1], ss[0])];
|
||||
if (eblk[crcerrs] >= nblks) return(1);
|
||||
es[0] = ss[1];
|
||||
crcerrs++;
|
||||
if (++crcerrs > 3) return(1);
|
||||
break;
|
||||
|
||||
case 1: /* 1 error (+ possible failures) */
|
||||
@ -394,7 +452,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
} else { /* add failure */
|
||||
eblk[crcerrs] = alpha_log[divide(i1, i2)];
|
||||
if (eblk[crcerrs] >= nblks) return(1);
|
||||
crcerrs++;
|
||||
if (++crcerrs > 3) return(1);
|
||||
if (!calculate_inverse(crcerrs, eblk, &inv)) return(1);
|
||||
}
|
||||
determine(crcerrs, &inv, ss, es);
|
||||
@ -411,7 +469,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
|
||||
/* Make corrections. */
|
||||
for (i = 0; i < crcerrs; i++) {
|
||||
data[eblk[i] * QCV_BLKSIZE+col] ^= es[i];
|
||||
data[(eblk[i] << 10) | col] ^= es[i];
|
||||
ss[0] ^= divide_out(es[i], eblk[i]);
|
||||
ss[1] ^= es[i];
|
||||
ss[2] ^= multiply_out(es[i], eblk[i]);
|
||||
|
||||
@ -1,7 +1,8 @@
|
||||
# $Id$
|
||||
# $Id: Makefile,v 1.2 1994/02/07 08:40:16 rgrimes Exp $
|
||||
|
||||
PROG= ft
|
||||
MAN8= ft.8
|
||||
SRCS= ft.c ftecc.c
|
||||
COPTS= -O2 -finline-functions -funroll-loops -fexpensive-optimizations
|
||||
|
||||
.include <bsd.prog.mk>
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
/*
|
||||
* Copyright (c) 1993 Steve Gerakines
|
||||
* Copyright (c) 1993, 1994 Steve Gerakines
|
||||
*
|
||||
* This is freely redistributable software. You may do anything you
|
||||
* wish with it, so long as the above notice stays intact.
|
||||
@ -18,6 +18,10 @@
|
||||
*
|
||||
* ft.c - simple floppy tape filter
|
||||
*
|
||||
* 06/07/94 v1.0 ++sg
|
||||
* Added support for tape retension. Added retries for ecc failures.
|
||||
* Moved to release.
|
||||
*
|
||||
* 01/28/94 v0.3b (Jim Babb)
|
||||
* Fixed bug when all sectors in a segment are marked bad.
|
||||
*
|
||||
@ -27,7 +31,7 @@
|
||||
* 09/02/93 v0.2 pl01
|
||||
* Initial revision.
|
||||
*
|
||||
* usage: ftfilt [ -f tape ] [ description ]
|
||||
* usage: ft [ -f tape ] [ description ]
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
@ -51,6 +55,7 @@ int tvlast; /* TRUE if last volume in set */
|
||||
long tvsize = 0; /* tape volume size in bytes */
|
||||
long tvtime = NULL; /* tape change time */
|
||||
char *tvnote = ""; /* tape note */
|
||||
int doretension = 0; /* TRUE if we should retension tape */
|
||||
|
||||
/* Lookup the badmap for a given track and segment. */
|
||||
#define BADMAP(t,s) hptr->qh_badmap[(t)*geo.g_segtrk+(s)]
|
||||
@ -62,45 +67,22 @@ char *tvnote = ""; /* tape note */
|
||||
#define equal(s1,s2) (strcmp(s1, s2) == 0)
|
||||
|
||||
|
||||
|
||||
/* Entry */
|
||||
main(int argc, char *argv[])
|
||||
/*
|
||||
* Print tape usage and then leave.
|
||||
*/
|
||||
void
|
||||
usage(void)
|
||||
{
|
||||
int r, s;
|
||||
char *tape, *getenv();
|
||||
|
||||
if (argc > 2 && (equal(argv[1], "-t") || equal(argv[1], "-f"))) {
|
||||
argc -= 2;
|
||||
tape = argv[2];
|
||||
argv += 2;
|
||||
} else
|
||||
if ((tape = getenv("TAPE")) == NULL)
|
||||
tape = DEFQIC;
|
||||
if (argc > 1) {
|
||||
tvnote = argv[1];
|
||||
if (strlen(tvnote) > 18) argv[1][18] = '\0';
|
||||
}
|
||||
|
||||
/* Open the tape device */
|
||||
if ((tfd = open(tape, 2)) < 0) {
|
||||
perror(tape);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
if (!isatty(0))
|
||||
do_write();
|
||||
else if (!isatty(1))
|
||||
do_read();
|
||||
else
|
||||
do_getname();
|
||||
|
||||
close(tfd);
|
||||
exit(0);
|
||||
fprintf(stderr, "usage: ft [ -r ] [ -f device ] [ \"description\" ]\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
|
||||
/* Check status of tape drive */
|
||||
int check_stat(int fd, int wr)
|
||||
/*
|
||||
* Check status of tape drive
|
||||
*/
|
||||
int
|
||||
check_stat(int fd, int wr)
|
||||
{
|
||||
int r, s;
|
||||
int sawit = 0;
|
||||
@ -138,8 +120,11 @@ int check_stat(int fd, int wr)
|
||||
}
|
||||
|
||||
|
||||
|
||||
ULONG qtimeval(time_t t)
|
||||
/*
|
||||
* Convert time_t value to QIC time value.
|
||||
*/
|
||||
ULONG
|
||||
qtimeval(time_t t)
|
||||
{
|
||||
struct tm *tp;
|
||||
ULONG r;
|
||||
@ -154,8 +139,12 @@ ULONG qtimeval(time_t t)
|
||||
return(r);
|
||||
}
|
||||
|
||||
/* Return tm struct from QIC date format. */
|
||||
struct tm *qtime(UCHAR *qt)
|
||||
|
||||
/*
|
||||
* Return tm struct from QIC date format.
|
||||
*/
|
||||
struct tm *
|
||||
qtime(UCHAR *qt)
|
||||
{
|
||||
ULONG *vp = (ULONG *)qt;
|
||||
struct tm t;
|
||||
@ -178,7 +167,10 @@ struct tm *qtime(UCHAR *qt)
|
||||
return(localtime(&tv));
|
||||
}
|
||||
|
||||
/* Return a string, zero terminated */
|
||||
|
||||
/*
|
||||
* Return a string, zero terminated.
|
||||
*/
|
||||
char *qstr(char *str, int nchar)
|
||||
{
|
||||
static char tstr[256];
|
||||
@ -187,7 +179,11 @@ char *qstr(char *str, int nchar)
|
||||
return(tstr);
|
||||
}
|
||||
|
||||
/* Read header from tape */
|
||||
|
||||
/*
|
||||
* Read header from tape
|
||||
*/
|
||||
int
|
||||
get_header(int fd)
|
||||
{
|
||||
int r, sn, bytes;
|
||||
@ -238,6 +234,9 @@ get_header(int fd)
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Open /dev/tty and ask for next volume.
|
||||
*/
|
||||
ask_vol(int vn)
|
||||
{
|
||||
FILE *inp;
|
||||
@ -255,21 +254,26 @@ ask_vol(int vn)
|
||||
}
|
||||
|
||||
|
||||
/* Return the name of the tape only. */
|
||||
do_getname()
|
||||
/*
|
||||
* Return the name of the tape only.
|
||||
*/
|
||||
void
|
||||
do_getname(void)
|
||||
{
|
||||
if (check_stat(tfd, 0)) exit(1);
|
||||
if (get_header(tfd)) exit(1);
|
||||
fprintf(stderr, "\"%s\" - %s",
|
||||
qstr(hptr->qh_tname,44), asctime(qtime(hptr->qh_chgdate)));
|
||||
ioctl(tfd, QIOREWIND);
|
||||
}
|
||||
|
||||
|
||||
/* Extract data from tape to stdout */
|
||||
do_read()
|
||||
/*
|
||||
* Extract data from tape to stdout.
|
||||
*/
|
||||
void
|
||||
do_read(void)
|
||||
{
|
||||
int sno, vno, sbytes, r;
|
||||
int sno, vno, sbytes, r, eccfails;
|
||||
long curpos;
|
||||
char *hname;
|
||||
QIC_Segment s;
|
||||
@ -281,6 +285,13 @@ do_read()
|
||||
ask_vol(vno);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (doretension) {
|
||||
ioctl(tfd, QIOBOT);
|
||||
ioctl(tfd, QIOEOT);
|
||||
ioctl(tfd, QIOBOT);
|
||||
}
|
||||
|
||||
if (get_header(tfd)) {
|
||||
ask_vol(vno);
|
||||
continue;
|
||||
@ -303,36 +314,50 @@ do_read()
|
||||
|
||||
/* Process this volume */
|
||||
curpos = 0;
|
||||
for (sno = hptr->qh_first; tvsize > 0; sno++) {
|
||||
eccfails = 0;
|
||||
sno = hptr->qh_first;
|
||||
while (tvsize > 0) {
|
||||
s.sg_trk = sno / geo.g_segtrk;
|
||||
s.sg_seg = sno % geo.g_segtrk;
|
||||
s.sg_badmap = BADMAP(s.sg_trk,s.sg_seg);
|
||||
sbytes = sect_bytes(s.sg_badmap) - QCV_ECCSIZE;
|
||||
s.sg_data = (UCHAR *)&buff[0];
|
||||
|
||||
/* skip segments with *all* sectors flagged as bad */
|
||||
if (sbytes > 0) {
|
||||
if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD");
|
||||
r = check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap);
|
||||
if (r) fprintf(stderr, "** warning: ecc failed at byte %ld\n",
|
||||
curpos);
|
||||
if (tvsize < sbytes) sbytes = tvsize;
|
||||
write(1, s.sg_data, sbytes);
|
||||
tvsize -= sbytes;
|
||||
curpos += sbytes;
|
||||
if (sbytes <= 0) {
|
||||
sno++;
|
||||
continue;
|
||||
}
|
||||
if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD");
|
||||
|
||||
if (check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap)) {
|
||||
if (++eccfails <= 5) {
|
||||
fprintf(stderr,
|
||||
"ft: retry %d at segment %d byte %ld\n",
|
||||
eccfails, sno, curpos);
|
||||
continue;
|
||||
} else
|
||||
fprintf(stderr,
|
||||
"ft: *** ecc failure in segment %d at byte %ld\n",
|
||||
sno, curpos);
|
||||
}
|
||||
if (tvsize < sbytes) sbytes = tvsize;
|
||||
write(1, s.sg_data, sbytes);
|
||||
tvsize -= sbytes;
|
||||
curpos += sbytes;
|
||||
sno++;
|
||||
eccfails = 0;
|
||||
}
|
||||
if (tvlast) break;
|
||||
ioctl(tfd, QIOREWIND);
|
||||
ask_vol(++vno);
|
||||
}
|
||||
ioctl(tfd, QIOREWIND);
|
||||
return(0);
|
||||
}
|
||||
|
||||
|
||||
/* Dump data from stdin to tape */
|
||||
do_write()
|
||||
/*
|
||||
* Dump data from stdin to tape.
|
||||
*/
|
||||
void
|
||||
do_write(void)
|
||||
{
|
||||
int sno, vno, amt, sbytes;
|
||||
int c, maxseg, r;
|
||||
@ -348,6 +373,13 @@ do_write()
|
||||
ask_vol(vno);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (doretension) {
|
||||
ioctl(tfd, QIOBOT);
|
||||
ioctl(tfd, QIOEOT);
|
||||
ioctl(tfd, QIOBOT);
|
||||
}
|
||||
|
||||
if (get_header(tfd)) {
|
||||
ask_vol(vno);
|
||||
continue;
|
||||
@ -376,6 +408,7 @@ do_write()
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* skip the segment if *all* sectors are flagged as bad */
|
||||
if (amt) {
|
||||
if (amt < sbytes)
|
||||
@ -410,7 +443,7 @@ do_write()
|
||||
if (ioctl(tfd, QIOWRITE, &s) < 0) {
|
||||
perror("QIOWRITE");
|
||||
exit(1);
|
||||
}
|
||||
}
|
||||
}
|
||||
if (dhsn >= 0) {
|
||||
s.sg_trk = dhsn / geo.g_segtrk;
|
||||
@ -428,5 +461,57 @@ do_write()
|
||||
if (tvlast) break;
|
||||
ask_vol(++vno);
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Entry.
|
||||
*/
|
||||
void
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
int r, s, i;
|
||||
char *tape, *getenv();
|
||||
|
||||
|
||||
/* Get device from environment, command line will override. */
|
||||
if ((tape = getenv("TAPE")) == NULL) tape = DEFQIC;
|
||||
|
||||
/* Process args. */
|
||||
for (i = 1; i < argc; i++) {
|
||||
if (argv[i][0] != '-') break;
|
||||
switch (argv[i][1]) {
|
||||
case 'f':
|
||||
case 't':
|
||||
if (i == (argc - 1)) usage();
|
||||
tape = argv[++i];
|
||||
break;
|
||||
case 'r':
|
||||
doretension = 1;
|
||||
break;
|
||||
default:
|
||||
usage();
|
||||
}
|
||||
}
|
||||
if (i < (argc - 1)) usage();
|
||||
if (i < argc) {
|
||||
tvnote = argv[i];
|
||||
if (strlen(tvnote) > 18) argv[i][18] = '\0';
|
||||
}
|
||||
|
||||
/* Open the tape device */
|
||||
if ((tfd = open(tape, 2)) < 0) {
|
||||
perror(tape);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
if (!isatty(0))
|
||||
do_write();
|
||||
else if (!isatty(1))
|
||||
do_read();
|
||||
else
|
||||
do_getname();
|
||||
|
||||
close(tfd);
|
||||
exit(0);
|
||||
}
|
||||
|
||||
@ -17,6 +17,11 @@
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* ftecc.c - QIC-40/80 Reed-Solomon error correction
|
||||
* 05/30/94 v1.0 ++sg
|
||||
* Did some minor optimization. The multiply by 0xc0 was a dog so it
|
||||
* was replaced with a table lookup. Fixed a couple of places where
|
||||
* bad sectors could go unnoticed. Moved to release.
|
||||
*
|
||||
* 03/22/94 v0.4
|
||||
* Major re-write. It can handle everything required by QIC now.
|
||||
*
|
||||
@ -111,6 +116,45 @@ static UCHAR alpha_log[] = {
|
||||
};
|
||||
|
||||
|
||||
/*
|
||||
* Multiplication table for 0xc0.
|
||||
*/
|
||||
static UCHAR mult_c0[] = {
|
||||
0x00, 0xc0, 0x07, 0xc7, 0x0e, 0xce, 0x09, 0xc9,
|
||||
0x1c, 0xdc, 0x1b, 0xdb, 0x12, 0xd2, 0x15, 0xd5,
|
||||
0x38, 0xf8, 0x3f, 0xff, 0x36, 0xf6, 0x31, 0xf1,
|
||||
0x24, 0xe4, 0x23, 0xe3, 0x2a, 0xea, 0x2d, 0xed,
|
||||
0x70, 0xb0, 0x77, 0xb7, 0x7e, 0xbe, 0x79, 0xb9,
|
||||
0x6c, 0xac, 0x6b, 0xab, 0x62, 0xa2, 0x65, 0xa5,
|
||||
0x48, 0x88, 0x4f, 0x8f, 0x46, 0x86, 0x41, 0x81,
|
||||
0x54, 0x94, 0x53, 0x93, 0x5a, 0x9a, 0x5d, 0x9d,
|
||||
0xe0, 0x20, 0xe7, 0x27, 0xee, 0x2e, 0xe9, 0x29,
|
||||
0xfc, 0x3c, 0xfb, 0x3b, 0xf2, 0x32, 0xf5, 0x35,
|
||||
0xd8, 0x18, 0xdf, 0x1f, 0xd6, 0x16, 0xd1, 0x11,
|
||||
0xc4, 0x04, 0xc3, 0x03, 0xca, 0x0a, 0xcd, 0x0d,
|
||||
0x90, 0x50, 0x97, 0x57, 0x9e, 0x5e, 0x99, 0x59,
|
||||
0x8c, 0x4c, 0x8b, 0x4b, 0x82, 0x42, 0x85, 0x45,
|
||||
0xa8, 0x68, 0xaf, 0x6f, 0xa6, 0x66, 0xa1, 0x61,
|
||||
0xb4, 0x74, 0xb3, 0x73, 0xba, 0x7a, 0xbd, 0x7d,
|
||||
0x47, 0x87, 0x40, 0x80, 0x49, 0x89, 0x4e, 0x8e,
|
||||
0x5b, 0x9b, 0x5c, 0x9c, 0x55, 0x95, 0x52, 0x92,
|
||||
0x7f, 0xbf, 0x78, 0xb8, 0x71, 0xb1, 0x76, 0xb6,
|
||||
0x63, 0xa3, 0x64, 0xa4, 0x6d, 0xad, 0x6a, 0xaa,
|
||||
0x37, 0xf7, 0x30, 0xf0, 0x39, 0xf9, 0x3e, 0xfe,
|
||||
0x2b, 0xeb, 0x2c, 0xec, 0x25, 0xe5, 0x22, 0xe2,
|
||||
0x0f, 0xcf, 0x08, 0xc8, 0x01, 0xc1, 0x06, 0xc6,
|
||||
0x13, 0xd3, 0x14, 0xd4, 0x1d, 0xdd, 0x1a, 0xda,
|
||||
0xa7, 0x67, 0xa0, 0x60, 0xa9, 0x69, 0xae, 0x6e,
|
||||
0xbb, 0x7b, 0xbc, 0x7c, 0xb5, 0x75, 0xb2, 0x72,
|
||||
0x9f, 0x5f, 0x98, 0x58, 0x91, 0x51, 0x96, 0x56,
|
||||
0x83, 0x43, 0x84, 0x44, 0x8d, 0x4d, 0x8a, 0x4a,
|
||||
0xd7, 0x17, 0xd0, 0x10, 0xd9, 0x19, 0xde, 0x1e,
|
||||
0xcb, 0x0b, 0xcc, 0x0c, 0xc5, 0x05, 0xc2, 0x02,
|
||||
0xef, 0x2f, 0xe8, 0x28, 0xe1, 0x21, 0xe6, 0x26,
|
||||
0xf3, 0x33, 0xf4, 0x34, 0xfd, 0x3d, 0xfa, 0x3a
|
||||
};
|
||||
|
||||
|
||||
/*
|
||||
* Return number of sectors available in a segment.
|
||||
*/
|
||||
@ -142,29 +186,37 @@ sect_bytes(ULONG badmap)
|
||||
/*
|
||||
* Multiply two numbers in the field.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
multiply(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp;
|
||||
|
||||
if (!a || !b) return(0);
|
||||
return(alpha_power[(alpha_log[a] + alpha_log[b]) % 255]);
|
||||
tmp = alpha_log[a] + alpha_log[b];
|
||||
if (tmp > 254) tmp -= 255;
|
||||
return(alpha_power[tmp]);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Multiply by an exponent.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
multiply_out(UCHAR a, int b)
|
||||
{
|
||||
int tmp;
|
||||
|
||||
if (!a) return(0);
|
||||
return(alpha_power[(alpha_log[a] + b) % 255]);
|
||||
tmp = alpha_log[a] + b;
|
||||
if (tmp > 254) tmp -= 255;
|
||||
return(alpha_power[tmp]);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Divide two numbers.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
divide(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp;
|
||||
@ -179,7 +231,7 @@ divide(UCHAR a, UCHAR b)
|
||||
/*
|
||||
* Divide using exponent.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
divide_out(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp;
|
||||
@ -194,13 +246,13 @@ divide_out(UCHAR a, UCHAR b)
|
||||
/*
|
||||
* This returns the value z^{a-b}.
|
||||
*/
|
||||
static UCHAR
|
||||
static inline UCHAR
|
||||
z_of_ab(UCHAR a, UCHAR b)
|
||||
{
|
||||
int tmp = a - b;
|
||||
|
||||
if (tmp < 0) tmp += 255;
|
||||
return(alpha_power[tmp % 255]);
|
||||
return(alpha_power[tmp]);
|
||||
}
|
||||
|
||||
|
||||
@ -208,12 +260,13 @@ z_of_ab(UCHAR a, UCHAR b)
|
||||
* Calculate the inverse matrix for two or three errors. Returns 0
|
||||
* if there is no inverse or 1 if successful.
|
||||
*/
|
||||
static int
|
||||
static inline int
|
||||
calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
{
|
||||
/* First some variables to remember some of the results. */
|
||||
UCHAR z20, z10, z21, z12, z01, z02;
|
||||
UCHAR i0, i1, i2;
|
||||
UCHAR iv0, iv1, iv2;
|
||||
|
||||
if (nerrs < 2) return(1);
|
||||
if (nerrs > 3) return(0);
|
||||
@ -243,21 +296,21 @@ calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
if (!inv->log_denom) return(0);
|
||||
inv->log_denom = 255 - alpha_log[inv->log_denom];
|
||||
|
||||
inv->zs[0][0] = multiply_out(alpha_power[i1] ^ alpha_power[i2],
|
||||
inv->log_denom);
|
||||
iv0 = alpha_power[255 - i0];
|
||||
iv1 = alpha_power[255 - i1];
|
||||
iv2 = alpha_power[255 - i2];
|
||||
i0 = alpha_power[i0];
|
||||
i1 = alpha_power[i1];
|
||||
i2 = alpha_power[i2];
|
||||
inv->zs[0][0] = multiply_out(i1 ^ i2, inv->log_denom);
|
||||
inv->zs[0][1] = multiply_out(z21 ^ z12, inv->log_denom);
|
||||
inv->zs[0][2] = multiply_out(alpha_power[255-i1] ^ alpha_power[255-i2],
|
||||
inv->log_denom);
|
||||
inv->zs[1][0] = multiply_out(alpha_power[i0] ^ alpha_power[i2],
|
||||
inv->log_denom);
|
||||
inv->zs[0][2] = multiply_out(iv1 ^ iv2, inv->log_denom);
|
||||
inv->zs[1][0] = multiply_out(i0 ^ i2, inv->log_denom);
|
||||
inv->zs[1][1] = multiply_out(z20 ^ z02, inv->log_denom);
|
||||
inv->zs[1][2] = multiply_out(alpha_power[255-i0] ^ alpha_power[255-i2],
|
||||
inv->log_denom);
|
||||
inv->zs[2][0] = multiply_out(alpha_power[i0] ^ alpha_power[i1],
|
||||
inv->log_denom);
|
||||
inv->zs[1][2] = multiply_out(iv0 ^ iv2, inv->log_denom);
|
||||
inv->zs[2][0] = multiply_out(i0 ^ i1, inv->log_denom);
|
||||
inv->zs[2][1] = multiply_out(z10 ^ z01, inv->log_denom);
|
||||
inv->zs[2][2] = multiply_out(alpha_power[255-i0] ^ alpha_power[255-i1],
|
||||
inv->log_denom);
|
||||
inv->zs[2][2] = multiply_out(iv0 ^ iv1, inv->log_denom);
|
||||
}
|
||||
return(1);
|
||||
}
|
||||
@ -266,7 +319,7 @@ calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv)
|
||||
/*
|
||||
* Determine the error magnitudes for a given matrix and syndromes.
|
||||
*/
|
||||
static void
|
||||
static inline void
|
||||
determine(int nerrs, struct inv_mat *inv, UCHAR *ss, UCHAR *es)
|
||||
{
|
||||
UCHAR tmp;
|
||||
@ -283,21 +336,22 @@ determine(int nerrs, struct inv_mat *inv, UCHAR *ss, UCHAR *es)
|
||||
/*
|
||||
* Compute the 3 syndrome values.
|
||||
*/
|
||||
static int
|
||||
static inline int
|
||||
compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss)
|
||||
{
|
||||
UCHAR r0, r1, r2, t1, t2;
|
||||
UCHAR *rptr;
|
||||
int row;
|
||||
|
||||
rptr = &data[col];
|
||||
rptr = data + col;
|
||||
data += nblks << 10;
|
||||
r0 = r1 = r2 = 0;
|
||||
for (row = 0; row < nblks; row++, rptr += QCV_BLKSIZE) {
|
||||
while (rptr < data) {
|
||||
t1 = *rptr ^ r0;
|
||||
t2 = multiply(0xc0, t1);
|
||||
t2 = mult_c0[t1];
|
||||
r0 = t2 ^ r1;
|
||||
r1 = t2 ^ r2;
|
||||
r2 = t1;
|
||||
rptr += QCV_BLKSIZE;
|
||||
}
|
||||
if (r0 || r1 || r2) {
|
||||
ss[0] = divide_out(r0 ^ divide_out(r1 ^ divide_out(r2, 1), 1), nblks);
|
||||
@ -315,24 +369,28 @@ compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss)
|
||||
int
|
||||
set_parity (UCHAR *data, ULONG badmap)
|
||||
{
|
||||
int col, row, max;
|
||||
UCHAR r0, r1, r2, t1, t2;
|
||||
UCHAR *rptr;
|
||||
int max, row, col;
|
||||
|
||||
max = sect_count(badmap) - 3;
|
||||
for (col = 0; col < QCV_BLKSIZE; col++, data++) {
|
||||
col = QCV_BLKSIZE;
|
||||
while (col--) {
|
||||
rptr = data;
|
||||
r0 = r1 = r2 = 0;
|
||||
for (row = 0; row < max; row++, rptr += QCV_BLKSIZE) {
|
||||
row = max;
|
||||
while (row--) {
|
||||
t1 = *rptr ^ r0;
|
||||
t2 = multiply(0xc0, t1);
|
||||
t2 = mult_c0[t1];
|
||||
r0 = t2 ^ r1;
|
||||
r1 = t2 ^ r2;
|
||||
r2 = t1;
|
||||
rptr += QCV_BLKSIZE;
|
||||
}
|
||||
*rptr = r0; rptr += QCV_BLKSIZE;
|
||||
*rptr = r1; rptr += QCV_BLKSIZE;
|
||||
*rptr = r2;
|
||||
data++;
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
@ -359,8 +417,8 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
if (crcmap) {
|
||||
for (i = 0; i < nblks; i++) {
|
||||
if (crcmap & (1 << i)) {
|
||||
if (crcerrs == 3) return(1);
|
||||
eblk[crcerrs++] = i;
|
||||
if (crcerrs >= 3) break;
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -380,7 +438,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
eblk[crcerrs] = alpha_log[divide(ss[1], ss[0])];
|
||||
if (eblk[crcerrs] >= nblks) return(1);
|
||||
es[0] = ss[1];
|
||||
crcerrs++;
|
||||
if (++crcerrs > 3) return(1);
|
||||
break;
|
||||
|
||||
case 1: /* 1 error (+ possible failures) */
|
||||
@ -394,7 +452,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
} else { /* add failure */
|
||||
eblk[crcerrs] = alpha_log[divide(i1, i2)];
|
||||
if (eblk[crcerrs] >= nblks) return(1);
|
||||
crcerrs++;
|
||||
if (++crcerrs > 3) return(1);
|
||||
if (!calculate_inverse(crcerrs, eblk, &inv)) return(1);
|
||||
}
|
||||
determine(crcerrs, &inv, ss, es);
|
||||
@ -411,7 +469,7 @@ check_parity(UCHAR *data, ULONG badmap, ULONG crcmap)
|
||||
|
||||
/* Make corrections. */
|
||||
for (i = 0; i < crcerrs; i++) {
|
||||
data[eblk[i] * QCV_BLKSIZE+col] ^= es[i];
|
||||
data[(eblk[i] << 10) | col] ^= es[i];
|
||||
ss[0] ^= divide_out(es[i], eblk[i]);
|
||||
ss[1] ^= es[i];
|
||||
ss[2] ^= multiply_out(es[i], eblk[i]);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user