src/libpart/isofs.c

   1 /*
   2  * <isofs.c>
   3  *
   4  * Open Hack'Ware BIOS ISOFS partition type management
   5  *
   6  * Copyright (c) 2004-2005 Jocelyn Mayer
   7  *
   8  *   This program is free software; you can redistribute it and/or
   9  *   modify it under the terms of the GNU General Public License V2
  10  *   as published by the Free Software Foundation
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include "bios.h"
  25 #include "libpart.h"
  26
  27 /* ISO FS partitions handlers */
  28 #define ISOFS_BLOCSIZE (2048)
  29
  30 /* Generic ISO fs descriptor */
  31 typedef struct isofs_desc_t isofs_desc_t;
  32 struct isofs_desc_t {
  33     uint8_t type;
  34     uint8_t ID[5];
  35     uint8_t version;
  36     uint8_t data[2041];
  37 } __attribute__ ((packed));
  38
  39 typedef struct iso_primary_desc_t iso_primary_desc_t;
  40 struct iso_primary_desc_t {
  41     uint8_t type;
  42     uint8_t ID[5];
  43     uint8_t version;
  44     uint8_t pad0;
  45     uint8_t system_id[32];
  46     uint8_t volume_id[32];
  47     uint8_t pad1[8];
  48     uint32_t volume_size;
  49 } __attribute__ ((packed));
  50
  51 /* The only descriptor we're interrested in here
  52  * is El-torito boot descriptor
  53  */
  54 typedef struct isofs_bootdesc_t isofs_bootdesc_t;
  55 struct isofs_bootdesc_t {
  56     uint8_t type;
  57     uint8_t ID[5];
  58     uint8_t version;
  59     uint8_t sys_ID[32];
  60     uint8_t pad[32];
  61     uint32_t catalog;
  62     uint8_t data[1973];
  63 } __attribute__ ((packed));
  64
  65 #define ISO_BOOTABLE 0x88
  66 enum {
  67     ISOBOOT_IX86 = 0,
  68     ISOBOOT_PPC  = 1,
  69     ISOBOOT_MAC  = 2,
  70 };
  71
  72 enum {
  73     ISOMEDIA_NOEMUL = 0,
  74     ISOMEDIA_FL12   = 1,
  75     ISOMEDIA_FL144  = 2,
  76     ISOMEDIA_FL288  = 3,
  77     ISOMEDIA_HD     = 4,
  78 };
  79
  80 typedef struct isofs_validdesc_t isofs_validdesc_t;
  81 struct isofs_validdesc_t {
  82     uint8_t ID;
  83     uint8_t arch;
  84     uint8_t pad[2];
  85     uint8_t name[24];
  86     uint8_t csum[2];
  87     uint16_t key;
  88 } __attribute__ ((packed));
  89
  90 typedef struct isofs_bootcat_t isofs_bootcat_t;
  91 struct isofs_bootcat_t {
  92     uint8_t bootable;
  93     uint8_t media;
  94     uint8_t segment[2];
  95     uint8_t sys_type;
  96     uint8_t pad;
  97     uint16_t nsect;
  98     uint32_t offset;
  99     uint8_t data[20];
 100 } __attribute__ ((packed));
 101
 102 part_t *isofs_probe_partitions (bloc_device_t *bd)
 103 {
 104     unsigned char name[32];
 105     void *buffer;
 106     union {
 107         isofs_desc_t desc;
 108         isofs_bootdesc_t bootdesc;
 109         iso_primary_desc_t primdesc;
 110     } *desc;
 111     isofs_validdesc_t *valid;
 112     isofs_bootcat_t *bootcat;
 113     part_t *part;
 114     uint32_t boot_desc;
 115     uint32_t nsect, bloc, offset, length;
 116     int i, end_reached;
 117
 118     part = NULL;
 119     buffer = malloc(ISOFS_BLOCSIZE);
 120     end_reached = 0;
 121     desc = buffer;
 122     boot_desc = -1;
 123     /* The descriptors start at offset 0x8000 */
 124     for (bloc = 0x8000 / ISOFS_BLOCSIZE; end_reached == 0; bloc++) {
 125         bd_seek(bd, bloc, 0);
 126         if (bd_read(bd, buffer, ISOFS_BLOCSIZE) < 0) {
 127             ERROR("%s bloc_read %d failed\n", __func__, bloc);
 128             goto error;
 129         }
 130         if (strncmp("CD001", desc->desc.ID, 5) != 0) {
 131             //            MSG("\rNo ISO9660 signature\n");
 132             goto error;
 133         }
 134         /* We found at least one valid descriptor */
 135         switch (desc->desc.type) {
 136         case 0x00:
 137             /* El-torito descriptor, great ! */
 138             DPRINTF("El-torito descriptor: %08x %d\n", desc->bootdesc.catalog,
 139                     (char *)&desc->bootdesc.catalog - (char *)desc);
 140             boot_desc = get_le32(&desc->bootdesc.catalog);
 141             break;
 142         case 0x01:
 143             /* ISOFS primary descriptor */
 144             DPRINTF("ISOFS primary descriptor (%d %d)\n",
 145                     get_le32(&desc->primdesc.volume_size) * 2048,
 146                     get_le32(&desc->primdesc.volume_size));
 147             break;
 148         case 0x02:
 149             /* ISOFS suplementary descriptor */
 150             DPRINTF("ISOFS suplementary descriptor\n");
 151             break;
 152         case 0xFF:
 153             /* End of descriptor list */
 154             DPRINTF("End of descriptor list\n");
 155             end_reached = 1;
 156             break;
 157         }
 158     }
 159     if (boot_desc != (uint32_t)(-1)) {
 160         /* Find the validation descriptor */
 161         bd_seek(bd, boot_desc, 0);
 162         for (i = 0; i < (ISOFS_BLOCSIZE / 64); i++) {
 163             DPRINTF("ISO catalog...\n");
 164             bd_read(bd, buffer, 64);
 165             valid = buffer;
 166 #if 1
 167             if (valid->ID != 0x01 || get_le16(&valid->key) != 0xAA55) {
 168                 ERROR("ISO catalog with invalid ID/key: %x %x\n",
 169                       valid->ID, valid->key);
 170                 continue;
 171             }
 172 #endif
 173 #if 0
 174 #if defined (__i386__)
 175             if (valid->arch != ISOBOOT_IX86) {
 176                 ERROR("ISO catalog not for x86: %d\n", valid->arch);
 177                 continue;
 178             }
 179 #elif defined (__powerpc__) || defined (_ARCH_PPC)
 180             if (valid->arch != ISOBOOT_PPC && valid->arch != ISOBOOT_MAC) {
 181                 ERROR("ISO catalog not for PPC: %d\n", valid->arch);
 182                 continue;
 183             }
 184 #else
 185             ERROR("Unknown host architecture !\n");
 186             continue;
 187 #endif
 188 #endif
 189             bootcat = (void *)(valid + 1);
 190             if (bootcat->bootable != ISO_BOOTABLE) {
 191                 ERROR("Non bootable ISO catalog\n");
 192                 continue;
 193             }
 194             nsect = get_le16(&bootcat->nsect);
 195             switch (bootcat->media) {
 196             case ISOMEDIA_NOEMUL:
 197                 length = nsect * ISOFS_BLOCSIZE;
 198                 dprintf("No emulation\n");
 199                 break;
 200             case ISOMEDIA_FL12:
 201                 length = 1200 * 1024;
 202                 dprintf("1.2 MB floppy\n");
 203                 break;
 204             case ISOMEDIA_FL144:
 205                 length = 1440 * 1024;
 206                 dprintf("1.44 MB floppy\n");
 207                 break;
 208             case ISOMEDIA_FL288:
 209                 length = 2880 * 1024;
 210                 dprintf("2.88 MB floppy\n");
 211                 break;
 212             case ISOMEDIA_HD:
 213                 length = nsect * ISOFS_BLOCSIZE;
 214                 dprintf("HD image\n");
 215                 break;
 216             default:
 217                 ERROR("Unknown media type: %d\n", bootcat->media);
 218                 continue;
 219             }
 220             offset = get_le32(&bootcat->offset);
 221             /* Register boot disc */
 222             part = malloc(sizeof(part_t));
 223             part->bd = bd;
 224             part_set_blocsize(bd, part, ISOFS_BLOCSIZE);
 225             part->start = offset;
 226             part->size = (length + ISOFS_BLOCSIZE - 1) / ISOFS_BLOCSIZE;
 227             part->boot_start.bloc = 0;
 228             part->boot_start.offset = 0;
 229             part->boot_size.bloc = length / ISOFS_BLOCSIZE;
 230             part->boot_size.offset = length % ISOFS_BLOCSIZE;
 231             part->boot_load = 0;
 232             part->boot_entry = 0;
 233             if (valid->name[0] == '\0') {
 234                 strcpy(name, "ISOFS");
 235             } else {
 236                 memcpy(name, valid->name, sizeof(valid->name));
 237                 name[sizeof(valid->name)] = '\0';
 238             }
 239             printf("Partition '%s': %p st %0x size %0x %d\n",
 240                    name, part, offset, length, bootcat->media);
 241             printf("    boot %0x %0x load %0x entry %0x\n",
 242                    part->boot_start.bloc, part->boot_size.bloc,
 243                    part->boot_load, part->boot_entry);
 244             part->flags = PART_TYPE_ISO9660 | PART_FLAG_BOOT;
 245             part_register(bd, part, name, i + 1);
 246             fs_raw_set_bootfile(part, part->boot_start.bloc,
 247                                 part->boot_start.offset,
 248                                 part->boot_size.bloc,
 249                                 part->boot_size.offset);
 250             break;
 251         }
 252     }
 253 error:
 254     free(buffer);
 255
 256     return part;
 257 }