xref: /original-bsd/sys/tahoe/stand/vdformat/smd_e.c (revision 319dde04)
1 #ifndef lint
2 static char sccsid[] = "@(#)smd_e.c	1.3 (Berkeley/CCI) 06/07/88";
3 #endif
4 
5 #include	"vdfmt.h"
6 
7 
8 /*
9 **	The sector format of the SMD controller looks like this:
10 **  32 bytes sector gap			(header error)
11 **   1 byte sync (0x19)			(header error)
12 **   2 bytes cylinder address		(header error)
13 **   1 byte track address		(header error)
14 **   1 byte sector address		(header error)
15 **   2 bytes alt cylinder address	(header error)
16 **   1 byte alt track address		(header error)
17 **   1 byte alt sector address		(header error)
18 **   4 bytes header crc			(header error)
19 **  34 bytes header gap			(data error)
20 ** 512 bytes data			(data error)
21 **   4 byte ecc				(data error)
22 **  ?? trailing pad			(data error)
23 */
24 
smd_e_decode_position(bad_entry,error)25 smd_e_decode_position(bad_entry, error)
26 register bs_entry *bad_entry;
27 register fmt_err *error;
28 {
29 	int	sector_length = lab->d_traksize / lab->d_nsectors;
30 	int	offset = (bad_entry->bs_offset-2) % sector_length;
31 	int	bytes = (bad_entry->bs_length / 8) + 4;
32 
33 	error->err_adr.cylinder = bad_entry->bs_cyl;
34 	error->err_adr.track = bad_entry->bs_trk;
35 	error->err_adr.sector = (bad_entry->bs_offset-2) / sector_length;
36 	if(error->err_adr.sector >= lab->d_nsectors) {
37 		error->err_adr.sector = lab->d_nsectors - 1;
38 		error->err_stat = DATA_ERROR;
39 	}
40 	else if((offset < 45) || ((offset+bytes) > sector_length))
41 		error->err_stat = HEADER_ERROR;
42 	else
43 		error->err_stat = DATA_ERROR;
44 }
45 
46 
47 /*
48 **
49 */
50 
smd_e_code_position(error,badent)51 smd_e_code_position(error, badent)
52 register fmt_err *error;
53 register bs_entry *badent;
54 {
55 	int		sector_length = lab->d_traksize / lab->d_nsectors;
56 
57 	badent->bs_length = 1;
58 	badent->bs_cyl = error->err_adr.cylinder;
59 	badent->bs_trk = error->err_adr.track;
60 	badent->bs_offset = error->err_adr.sector * sector_length;
61 	if(error->err_stat & HEADER_ERROR) {
62 		badent->bs_offset += 1;
63 	}
64 	else {
65 		badent->bs_offset += 60;
66 	}
67 	badent->bs_alt.cylinder = 0;
68 	badent->bs_alt.track = 0;
69 	badent->bs_alt.sector = 0;
70 	badent->bs_how = scanning;
71 }
72