/* * Definitions needed to perform bad sector * revectoring ala DEC STD 144. * * The bad sector information is located in the * first 5 even numbered sectors of the last * track of the disk pack. There are five * identical copies of the information, described * by the bad144 structure. * * Replacement sectors are allocated starting with * the first sector before the bad sector information * and working backwards towards the beginning of * the disk. A maximum of 126 bad sectors are supported. * The position of the bad sector in the bad sector table * determines which replacement sector it corresponds to. * * The bad sector information and replacement sectors * are conventionally only accessible through the * 'c' file system partition of the disk. If that * partition is used for a file system, the user is * responsible for making sure that it does not overlap * the bad sector information or any replacement sector.s */ #define NBADDESC 126 /* * known to be 512 bytes long */ struct bad144 { long bt_csn; /* cartridge serial number */ unsigned short bt_mbz; /* unused; should be 0 */ unsigned short bt_flag; /* -1 => alignment cartridge */ struct bt_bad { unsigned short bt_cyl; /* cylinder number of bad sector */ unsigned short bt_trksec; /* track and sector number */ } bt_bad[126]; }; #if KERNEL int bad144rep(); #endif