/* * Mach Operating System * Copyright (c) 1992, 1991 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. * * from: Mach, Revision 2.2 92/04/04 11:35:49 rpd * $Id: disk.c,v 1.3 1993/10/16 19:11:34 rgrimes Exp $ */ #include "boot.h" #ifdef DO_BAD144 #include #endif DO_BAD144 #include #define BIOS_DEV_FLOPPY 0x0 #define BIOS_DEV_WIN 0x80 #define BPS 512 #define SPT(di) ((di)&0xff) #define HEADS(di) ((((di)>>8)&0xff)+1) char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0}; #ifdef DO_BAD144 struct dkbad dkb; int do_bad144; int bsize; #endif DO_BAD144 int spt, spc; char *iodest; struct fs *fs; struct inode inode; int dosdev, unit, part, maj, boff, poff, bnum, cnt; /*#define EMBEDDED_DISKLABEL 1*/ extern struct disklabel disklabel; /*struct disklabel disklabel;*/ devopen() { struct dos_partition *dptr; struct disklabel *dl; int dosdev = inode.i_dev; int i, sector, di; di = get_diskinfo(dosdev); spc = (spt = SPT(di)) * HEADS(di); if (dosdev == 2) { boff = 0; part = (spt == 15 ? 3 : 1); } else { #ifdef EMBEDDED_DISKLABEL dl = &disklabel; #else EMBEDDED_DISKLABEL Bread(dosdev, 0); dptr = (struct dos_partition *)(((char *)0)+DOSPARTOFF); for (i = 0; i < NDOSPART; i++, dptr++) if (dptr->dp_typ == DOSPTYP_386BSD) break; sector = dptr->dp_start + LABELSECTOR; Bread(dosdev, sector++); dl=((struct disklabel *)0); disklabel = *dl; /* structure copy (maybe useful later)*/ #endif EMBEDDED_DISKLABEL if (dl->d_magic != DISKMAGIC) { printf("bad disklabel"); return 1; } if( (maj == 4) || (maj == 0) || (maj == 1)) { if (dl->d_type == DTYPE_SCSI) { maj = 4; /* use scsi as boot dev */ } else { maj = 0; /* must be ESDI/IDE */ } } boff = dl->d_partitions[part].p_offset; #ifdef DO_BAD144 bsize = dl->d_partitions[part].p_size; do_bad144 = 0; if (dl->d_flags & D_BADSECT) { /* this disk uses bad144 */ int i; int dkbbnum; struct dkbad *dkbptr; /* find the first readable bad144 sector */ /* some of this code is copied from ufs/disk_subr.c */ /* read a bad sector table */ dkbbnum = dl->d_secperunit - dl->d_nsectors; if (dl->d_secsize > DEV_BSIZE) dkbbnum *= dl->d_secsize / DEV_BSIZE; else dkbbnum /= DEV_BSIZE / dl->d_secsize; i = 0; do_bad144 = 0; do { /* XXX: what if the "DOS sector" < 512 bytes ??? */ Bread(dosdev, dkbbnum + i); dkbptr = (struct dkbad *) 0; /* XXX why is this not in ??? */ #define DKBAD_MAGIC 0x4321 if (dkbptr->bt_mbz == 0 && dkbptr->bt_flag == DKBAD_MAGIC) { dkb = *dkbptr; /* structure copy */ do_bad144 = 1; break; } i += 2; } while (i < 10 && i < dl->d_nsectors); if (!do_bad144) printf("Bad badsect table\n"); else printf("Using bad144 bad sector at %d\n", dkbbnum+i); } #endif DO_BAD144 } return 0; } devread() { int offset, sector = bnum; int dosdev = inode.i_dev; for (offset = 0; offset < cnt; offset += BPS) { Bread(dosdev, badsect(dosdev, sector++)); bcopy(0, iodest+offset, BPS); } } #define I_ADDR ((void *) 0) /* XXX where all reads go */ /* Read ahead buffer large enough for one track on a 1440K floppy. For * reading from floppies, the bootstrap has to be loaded on a 64K boundary * to ensure that this buffer doesn't cross a 64K DMA boundary. */ #define RA_SECTORS 18 static char ra_buf[RA_SECTORS * BPS]; static int ra_dev; static int ra_end; static int ra_first; Bread(dosdev,sector) int dosdev,sector; { if (dosdev != ra_dev || sector < ra_first || sector >= ra_end) { int cyl, head, sec, nsec; cyl = sector/spc; head = (sector % spc) / spt; sec = sector % spt; nsec = spt - sec; if (nsec > RA_SECTORS) nsec = RA_SECTORS; twiddle(); if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) { nsec = 1; twiddle(); while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) { printf("Error: C:%d H:%d S:%d\n", cyl, head, sec); twiddle(); } } ra_dev = dosdev; ra_first = sector; ra_end = sector + nsec; } bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS); } badsect(dosdev, sector) int dosdev, sector; { int i; #ifdef DO_BAD144 if (do_bad144) { u_short cyl; u_short head; u_short sec; int newsec; struct disklabel *dl = &disklabel; /* XXX */ /* from wd.c */ /* bt_cyl = cylinder number in sorted order */ /* bt_trksec is actually (head << 8) + sec */ /* only remap sectors in the partition */ if (sector < boff || sector >= boff + bsize) { goto no_remap; } cyl = sector / dl->d_secpercyl; head = (sector % dl->d_secpercyl) / dl->d_nsectors; sec = sector % dl->d_nsectors; sec = (head<<8) + sec; /* now, look in the table for a possible bad sector */ for (i=0; i<126; i++) { if (dkb.bt_bad[i].bt_cyl == cyl) { /* found same cylinder */ if (dkb.bt_bad[i].bt_trksec == sec) { /* FOUND! */ break; } } else if (dkb.bt_bad[i].bt_cyl > cyl) { i = 126; break; } } if (i == 126) { /* didn't find bad sector */ goto no_remap; } /* otherwise find replacement sector */ newsec = dl->d_secperunit - dl->d_nsectors - i -1; return newsec; } #endif DO_BAD144 no_remap: return sector; }