BSD 4_3_Tahoe release

[unix-history] / usr / src / sys / tahoestand / vdformat / smd_e.c

#ifndef lint
static char sccsid[] = "@(#)smd_e.c     1.3 (Berkeley/CCI) 6/7/88";
#endif

#include        "vdfmt.h"


/*
**      The sector format of the SMD controller looks like this:
**  32 bytes sector gap                 (header error)
**   1 byte sync (0x19)                 (header error)
**   2 bytes cylinder address           (header error)
**   1 byte track address               (header error)
**   1 byte sector address              (header error)
**   2 bytes alt cylinder address       (header error)
**   1 byte alt track address           (header error)
**   1 byte alt sector address          (header error)
**   4 bytes header crc                 (header error)
**  34 bytes header gap                 (data error)
** 512 bytes data                       (data error)
**   4 byte ecc                         (data error)
**  ?? trailing pad                     (data error)
*/

smd_e_decode_position(bad_entry, error)
register bs_entry *bad_entry;
register fmt_err *error;
{
       int     sector_length = lab->d_traksize / lab->d_nsectors;
       int     offset = (bad_entry->bs_offset-2) % sector_length;
       int     bytes = (bad_entry->bs_length / 8) + 4;

       error->err_adr.cylinder = bad_entry->bs_cyl;
       error->err_adr.track = bad_entry->bs_trk;
       error->err_adr.sector = (bad_entry->bs_offset-2) / sector_length;
       if(error->err_adr.sector >= lab->d_nsectors) {
               error->err_adr.sector = lab->d_nsectors - 1;
               error->err_stat = DATA_ERROR;
       }
       else if((offset < 45) || ((offset+bytes) > sector_length))
               error->err_stat = HEADER_ERROR;
       else 
               error->err_stat = DATA_ERROR;
}


/*
**
*/

smd_e_code_position(error, badent)
register fmt_err *error;
register bs_entry *badent;
{
       int             sector_length = lab->d_traksize / lab->d_nsectors;

       badent->bs_length = 1;
       badent->bs_cyl = error->err_adr.cylinder;
       badent->bs_trk = error->err_adr.track;
       badent->bs_offset = error->err_adr.sector * sector_length;
       if(error->err_stat & HEADER_ERROR) {
               badent->bs_offset += 1;
       }
       else {
               badent->bs_offset += 60;
       }
       badent->bs_alt.cylinder = 0;
       badent->bs_alt.track = 0;
       badent->bs_alt.sector = 0;
       badent->bs_how = scanning;
}