fs/partitions/nec98.c

   1 /*
   2  *  NEC PC-9800 series partition supports
   3  *
   4  *  Copyright (C) 1999  Kyoto University Microcomputer Club
   5  */
   6
   7 #include <linux/config.h>
   8 #include <linux/fs.h>
   9 #include <linux/genhd.h>
  10 #include <linux/kernel.h>
  11 #include <linux/hdreg.h>
  12
  13 #include "check.h"
  14 #include "nec98.h"
  15
  16 struct nec98_partition {
  17         __u8    mid;            /* 0x80 - active */
  18         __u8    sid;            /* 0x80 - bootable */
  19         __u16   pad1;           /* dummy for padding */
  20         __u8    ipl_sector;     /* IPL sector   */
  21         __u8    ipl_head;       /* IPL head     */
  22         __u16   ipl_cyl;        /* IPL cylinder */
  23         __u8    sector;         /* starting sector      */
  24         __u8    head;           /* starting head        */
  25         __u16   cyl;            /* starting cylinder    */
  26         __u8    end_sector;     /* end sector   */
  27         __u8    end_head;       /* end head     */
  28         __u16   end_cyl;        /* end cylinder */
  29         unsigned char name[16];
  30 } __attribute__((__packed__));
  31
  32 #define NEC98_BSD_PARTITION_MID 0x14
  33 #define NEC98_BSD_PARTITION_SID 0x44
  34 #define MID_SID_16(mid, sid)    (((mid) & 0xFF) | (((sid) & 0xFF) << 8))
  35 #define NEC98_BSD_PARTITION_MID_SID     \
  36         MID_SID_16(NEC98_BSD_PARTITION_MID, NEC98_BSD_PARTITION_SID)
  37 #define NEC98_VALID_PTABLE_ENTRY(P) \
  38         (!(P)->pad1 && (P)->cyl <= (P)->end_cyl)
  39
  40 extern int pc98_bios_param(struct block_device *bdev, int *ip);
  41
  42 static inline int
  43 is_valid_nec98_partition_table(const struct nec98_partition *ptable,
  44                                 __u8 nsectors, __u8 nheads)
  45 {
  46         int i;
  47         int valid = 0;
  48
  49         for (i = 0; i < 16; i++) {
  50                 if (!*(__u16 *)&ptable[i])
  51                         continue;       /* empty slot */
  52                 if (ptable[i].pad1      /* `pad1' contains junk */
  53                     || ptable[i].ipl_sector     >= nsectors
  54                     || ptable[i].sector         >= nsectors
  55                     || ptable[i].end_sector     >= nsectors
  56                     || ptable[i].ipl_head       >= nheads
  57                     || ptable[i].head           >= nheads
  58                     || ptable[i].end_head       >= nheads
  59                     || ptable[i].cyl > ptable[i].end_cyl)
  60                         return 0;
  61                 valid = 1;      /* We have a valid partition.  */
  62         }
  63         /* If no valid PC-9800-style partitions found,
  64            the disk may have other type of partition table.  */
  65         return valid;
  66 }
  67
  68 int nec98_partition(struct parsed_partitions *state, struct block_device *bdev)
  69 {
  70         unsigned int nr;
  71         struct hd_geometry geo;
  72         Sector sect;
  73         const struct nec98_partition *part;
  74         unsigned char *data;
  75         int sector_size = bdev_hardsect_size(bdev);
  76
  77         if (ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)&geo) != 0) {
  78                 printk(" unsupported disk (%s)\n", bdev->bd_disk->disk_name);
  79                 return 0;
  80         }
  81
  82 #ifdef NEC98_PARTITION_DEBUG
  83         printk("ioctl_by_bdev head=%d sect=%d\n", geo.heads, geo.sectors);
  84 #endif
  85         data = read_dev_sector(bdev, 0, &sect);
  86         if (!data) {
  87                 if (warn_no_part)
  88                         printk(" unable to read partition table\n");
  89                 return -1;
  90         }
  91
  92         /* magic(?) check */
  93         if (*(__u16 *)(data + sector_size - 2) != NEC98_PTABLE_MAGIC) {
  94                 put_dev_sector(sect);
  95                 return 0;
  96         }
  97
  98         put_dev_sector(sect);
  99         data = read_dev_sector(bdev, 1, &sect);
 100         if (!data) {
 101                 if (warn_no_part)
 102                         printk(" unable to read partition table\n");
 103                 return -1;
 104         }
 105
 106         if (!is_valid_nec98_partition_table((struct nec98_partition *)data,
 107                                              geo.sectors, geo.heads)) {
 108 #ifdef NEC98_PARTITION_DEBUG
 109                 if (warn_no_part)
 110                         printk(" partition table consistency check failed"
 111                                 " (not PC-9800 disk?)\n");
 112 #endif
 113                 put_dev_sector(sect);
 114                 return 0;
 115         }
 116
 117         part = (const struct nec98_partition *)data;
 118         for (nr = 0; nr < 16; nr++, part++) {
 119                 unsigned int start_sect, end_sect;
 120
 121                 if (part->mid == 0 || part->sid == 0)
 122                         continue;
 123
 124                 if (nr)
 125                         printk("     ");
 126
 127                 {       /* Print partition name. Fdisk98 might put NUL
 128                            characters in partition name... */
 129
 130                         int j;
 131                         unsigned char *p;
 132                         unsigned char buf[sizeof (part->name) * 2 + 1];
 133
 134                         for (p = buf, j = 0; j < sizeof (part->name); j++, p++)
 135                                 if ((*p = part->name[j]) < ' ') {
 136                                         *p++ = '^';
 137                                         *p = part->name[j] + '@';
 138                                 }
 139
 140                         *p = 0;
 141                         printk(" <%s>", buf);
 142                 }
 143                 start_sect = (part->cyl * geo.heads + part->head) * geo.sectors
 144                         + part->sector;
 145                 end_sect = (part->end_cyl + 1) * geo.heads * geo.sectors;
 146                 if (end_sect <= start_sect) {
 147                         printk(" (invalid partition info)\n");
 148                         continue;
 149                 }
 150
 151                 put_partition(state, nr + 1, start_sect, end_sect - start_sect);
 152 #ifdef CONFIG_BSD_DISKLABEL
 153                 if ((*(__u16 *)&part->mid & 0x7F7F)
 154                     == NEC98_BSD_PARTITION_MID_SID) {
 155                         printk("!");
 156                         /* NEC98_BSD_PARTITION_MID_SID is not valid SYSIND for
 157                            IBM PC's MS-DOS partition table, so we simply pass
 158                            it to bsd_disklabel_partition;
 159                            it will just print `<bsd: ... >'. */
 160                         parse_bsd(state, bdev, start_sect,
 161                                         end_sect - start_sect, nr + 1,
 162                                         "bsd98", BSD_MAXPARTITIONS);
 163                 }
 164 #endif
 165                 {       /* Pretty size printing. */
 166                         /* XXX sector size? */
 167                         unsigned int psize = (end_sect - start_sect) / 2;
 168                         int unit_char = 'K';
 169
 170                         if (psize > 99999) {
 171                                 psize >>= 10;
 172                                 unit_char = 'M';
 173                         }
 174                         printk(" %5d%cB (%5d-%5d)\n",
 175                                psize, unit_char, part->cyl, part->end_cyl);
 176                 }
 177         }
 178
 179         put_dev_sector(sect);
 180
 181         return nr ? 1 : 0;
 182 }
 183 \f
 184 /*
 185  * Local variables:
 186  * c-basic-offset: 8
 187  * End:
 188  */