qemu/pc-bios/s390-ccw/bootmap.c
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   1/*
   2 * QEMU S390 bootmap interpreter
   3 *
   4 * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   5 *
   6 * This work is licensed under the terms of the GNU GPL, version 2 or (at
   7 * your option) any later version. See the COPYING file in the top-level
   8 * directory.
   9 */
  10
  11#include "libc.h"
  12#include "s390-ccw.h"
  13#include "s390-arch.h"
  14#include "bootmap.h"
  15#include "virtio.h"
  16#include "bswap.h"
  17
  18#ifdef DEBUG
  19/* #define DEBUG_FALLBACK */
  20#endif
  21
  22#ifdef DEBUG_FALLBACK
  23#define dputs(txt) \
  24    do { sclp_print("zipl: " txt); } while (0)
  25#else
  26#define dputs(fmt, ...) \
  27    do { } while (0)
  28#endif
  29
  30/* Scratch space */
  31static uint8_t sec[MAX_SECTOR_SIZE*4] __attribute__((__aligned__(PAGE_SIZE)));
  32
  33const uint8_t el_torito_magic[] = "EL TORITO SPECIFICATION"
  34                                  "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
  35
  36/*
  37 * Match two CCWs located after PSW and eight filler bytes.
  38 * From libmagic and arch/s390/kernel/head.S.
  39 */
  40const uint8_t linux_s390_magic[] = "\x02\x00\x00\x18\x60\x00\x00\x50\x02\x00"
  41                                   "\x00\x68\x60\x00\x00\x50\x40\x40\x40\x40"
  42                                   "\x40\x40\x40\x40";
  43
  44static inline bool is_iso_vd_valid(IsoVolDesc *vd)
  45{
  46    const uint8_t vol_desc_magic[] = "CD001";
  47
  48    return !memcmp(&vd->ident[0], vol_desc_magic, 5) &&
  49           vd->version == 0x1 &&
  50           vd->type <= VOL_DESC_TYPE_PARTITION;
  51}
  52
  53/***********************************************************************
  54 * IPL an ECKD DASD (CDL or LDL/CMS format)
  55 */
  56
  57static unsigned char _bprs[8*1024]; /* guessed "max" ECKD sector size */
  58static const int max_bprs_entries = sizeof(_bprs) / sizeof(ExtEckdBlockPtr);
  59static uint8_t _s2[MAX_SECTOR_SIZE * 3] __attribute__((__aligned__(PAGE_SIZE)));
  60static void *s2_prev_blk = _s2;
  61static void *s2_cur_blk = _s2 + MAX_SECTOR_SIZE;
  62static void *s2_next_blk = _s2 + MAX_SECTOR_SIZE * 2;
  63
  64static inline void verify_boot_info(BootInfo *bip)
  65{
  66    IPL_assert(magic_match(bip->magic, ZIPL_MAGIC), "No zIPL sig in BootInfo");
  67    IPL_assert(bip->version == BOOT_INFO_VERSION, "Wrong zIPL version");
  68    IPL_assert(bip->bp_type == BOOT_INFO_BP_TYPE_IPL, "DASD is not for IPL");
  69    IPL_assert(bip->dev_type == BOOT_INFO_DEV_TYPE_ECKD, "DASD is not ECKD");
  70    IPL_assert(bip->flags == BOOT_INFO_FLAGS_ARCH, "Not for this arch");
  71    IPL_assert(block_size_ok(bip->bp.ipl.bm_ptr.eckd.bptr.size),
  72               "Bad block size in zIPL section of the 1st record.");
  73}
  74
  75static block_number_t eckd_block_num(EckdCHS *chs)
  76{
  77    const uint64_t sectors = virtio_get_sectors();
  78    const uint64_t heads = virtio_get_heads();
  79    const uint64_t cylinder = chs->cylinder
  80                            + ((chs->head & 0xfff0) << 12);
  81    const uint64_t head = chs->head & 0x000f;
  82    const block_number_t block = sectors * heads * cylinder
  83                               + sectors * head
  84                               + chs->sector
  85                               - 1; /* block nr starts with zero */
  86    return block;
  87}
  88
  89static bool eckd_valid_address(BootMapPointer *p)
  90{
  91    const uint64_t head = p->eckd.chs.head & 0x000f;
  92
  93    if (head >= virtio_get_heads()
  94        ||  p->eckd.chs.sector > virtio_get_sectors()
  95        ||  p->eckd.chs.sector <= 0) {
  96        return false;
  97    }
  98
  99    if (!virtio_guessed_disk_nature() &&
 100        eckd_block_num(&p->eckd.chs) >= virtio_get_blocks()) {
 101        return false;
 102    }
 103
 104    return true;
 105}
 106
 107static block_number_t load_eckd_segments(block_number_t blk, uint64_t *address)
 108{
 109    block_number_t block_nr;
 110    int j, rc;
 111    BootMapPointer *bprs = (void *)_bprs;
 112    bool more_data;
 113
 114    memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
 115    read_block(blk, bprs, "BPRS read failed");
 116
 117    do {
 118        more_data = false;
 119        for (j = 0;; j++) {
 120            block_nr = eckd_block_num(&bprs[j].xeckd.bptr.chs);
 121            if (is_null_block_number(block_nr)) { /* end of chunk */
 122                break;
 123            }
 124
 125            /* we need the updated blockno for the next indirect entry
 126             * in the chain, but don't want to advance address
 127             */
 128            if (j == (max_bprs_entries - 1)) {
 129                break;
 130            }
 131
 132            IPL_assert(block_size_ok(bprs[j].xeckd.bptr.size),
 133                       "bad chunk block size");
 134            IPL_assert(eckd_valid_address(&bprs[j]), "bad chunk ECKD addr");
 135
 136            if ((bprs[j].xeckd.bptr.count == 0) && unused_space(&(bprs[j+1]),
 137                sizeof(EckdBlockPtr))) {
 138                /* This is a "continue" pointer.
 139                 * This ptr should be the last one in the current
 140                 * script section.
 141                 * I.e. the next ptr must point to the unused memory area
 142                 */
 143                memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
 144                read_block(block_nr, bprs, "BPRS continuation read failed");
 145                more_data = true;
 146                break;
 147            }
 148
 149            /* Load (count+1) blocks of code at (block_nr)
 150             * to memory (address).
 151             */
 152            rc = virtio_read_many(block_nr, (void *)(*address),
 153                                  bprs[j].xeckd.bptr.count+1);
 154            IPL_assert(rc == 0, "code chunk read failed");
 155
 156            *address += (bprs[j].xeckd.bptr.count+1) * virtio_get_block_size();
 157        }
 158    } while (more_data);
 159    return block_nr;
 160}
 161
 162static bool find_zipl_boot_menu_banner(int *offset)
 163{
 164    int i;
 165
 166    /* Menu banner starts with "zIPL" */
 167    for (i = 0; i <= virtio_get_block_size() - 4; i++) {
 168        if (magic_match(s2_cur_blk + i, ZIPL_MAGIC_EBCDIC)) {
 169            *offset = i;
 170            return true;
 171        }
 172    }
 173
 174    return false;
 175}
 176
 177static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
 178{
 179    block_number_t cur_block_nr;
 180    block_number_t prev_block_nr = 0;
 181    block_number_t next_block_nr = 0;
 182    EckdStage1b *s1b = (void *)sec;
 183    int banner_offset;
 184    int i;
 185
 186    /* Get Stage1b data */
 187    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 188    read_block(s1b_block_nr, s1b, "Cannot read stage1b boot loader");
 189
 190    memset(_s2, FREE_SPACE_FILLER, sizeof(_s2));
 191
 192    /* Get Stage2 data */
 193    for (i = 0; i < STAGE2_BLK_CNT_MAX; i++) {
 194        cur_block_nr = eckd_block_num(&s1b->seek[i].chs);
 195
 196        if (!cur_block_nr || is_null_block_number(cur_block_nr)) {
 197            break;
 198        }
 199
 200        read_block(cur_block_nr, s2_cur_blk, "Cannot read stage2 boot loader");
 201
 202        if (find_zipl_boot_menu_banner(&banner_offset)) {
 203            /*
 204             * Load the adjacent blocks to account for the
 205             * possibility of menu data spanning multiple blocks.
 206             */
 207            if (prev_block_nr) {
 208                read_block(prev_block_nr, s2_prev_blk,
 209                           "Cannot read stage2 boot loader");
 210            }
 211
 212            if (i + 1 < STAGE2_BLK_CNT_MAX) {
 213                next_block_nr = eckd_block_num(&s1b->seek[i + 1].chs);
 214            }
 215
 216            if (next_block_nr) {
 217                read_block(next_block_nr, s2_next_blk,
 218                           "Cannot read stage2 boot loader");
 219            }
 220
 221            return menu_get_zipl_boot_index(s2_cur_blk + banner_offset);
 222        }
 223
 224        prev_block_nr = cur_block_nr;
 225    }
 226
 227    sclp_print("No zipl boot menu data found. Booting default entry.");
 228    return 0;
 229}
 230
 231static void run_eckd_boot_script(block_number_t bmt_block_nr,
 232                                 block_number_t s1b_block_nr)
 233{
 234    int i;
 235    unsigned int loadparm = get_loadparm_index();
 236    block_number_t block_nr;
 237    uint64_t address;
 238    BootMapTable *bmt = (void *)sec;
 239    BootMapScript *bms = (void *)sec;
 240
 241    if (menu_is_enabled_zipl()) {
 242        loadparm = eckd_get_boot_menu_index(s1b_block_nr);
 243    }
 244
 245    debug_print_int("loadparm", loadparm);
 246    IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
 247               " maximum number of boot entries allowed");
 248
 249    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 250    read_block(bmt_block_nr, sec, "Cannot read Boot Map Table");
 251
 252    block_nr = eckd_block_num(&bmt->entry[loadparm].xeckd.bptr.chs);
 253    IPL_assert(block_nr != -1, "Cannot find Boot Map Table Entry");
 254
 255    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 256    read_block(block_nr, sec, "Cannot read Boot Map Script");
 257
 258    for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD ||
 259                bms->entry[i].type == BOOT_SCRIPT_SIGNATURE; i++) {
 260
 261        /* We don't support secure boot yet, so we skip signature entries */
 262        if (bms->entry[i].type == BOOT_SCRIPT_SIGNATURE) {
 263            continue;
 264        }
 265
 266        address = bms->entry[i].address.load_address;
 267        block_nr = eckd_block_num(&bms->entry[i].blkptr.xeckd.bptr.chs);
 268
 269        do {
 270            block_nr = load_eckd_segments(block_nr, &address);
 271        } while (block_nr != -1);
 272    }
 273
 274    IPL_assert(bms->entry[i].type == BOOT_SCRIPT_EXEC,
 275               "Unknown script entry type");
 276    write_reset_psw(bms->entry[i].address.load_address); /* no return */
 277    jump_to_IPL_code(0); /* no return */
 278}
 279
 280static void ipl_eckd_cdl(void)
 281{
 282    XEckdMbr *mbr;
 283    EckdCdlIpl2 *ipl2 = (void *)sec;
 284    IplVolumeLabel *vlbl = (void *)sec;
 285    block_number_t bmt_block_nr, s1b_block_nr;
 286
 287    /* we have just read the block #0 and recognized it as "IPL1" */
 288    sclp_print("CDL\n");
 289
 290    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 291    read_block(1, ipl2, "Cannot read IPL2 record at block 1");
 292
 293    mbr = &ipl2->mbr;
 294    if (!magic_match(mbr, ZIPL_MAGIC)) {
 295        sclp_print("No zIPL section in IPL2 record.\n");
 296        return;
 297    }
 298    if (!block_size_ok(mbr->blockptr.xeckd.bptr.size)) {
 299        sclp_print("Bad block size in zIPL section of IPL2 record.\n");
 300        return;
 301    }
 302    if (!mbr->dev_type == DEV_TYPE_ECKD) {
 303        sclp_print("Non-ECKD device type in zIPL section of IPL2 record.\n");
 304        return;
 305    }
 306
 307    /* save pointer to Boot Map Table */
 308    bmt_block_nr = eckd_block_num(&mbr->blockptr.xeckd.bptr.chs);
 309
 310    /* save pointer to Stage1b Data */
 311    s1b_block_nr = eckd_block_num(&ipl2->stage1.seek[0].chs);
 312
 313    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 314    read_block(2, vlbl, "Cannot read Volume Label at block 2");
 315    if (!magic_match(vlbl->key, VOL1_MAGIC)) {
 316        sclp_print("Invalid magic of volume label block.\n");
 317        return;
 318    }
 319    if (!magic_match(vlbl->f.key, VOL1_MAGIC)) {
 320        sclp_print("Invalid magic of volser block.\n");
 321        return;
 322    }
 323    print_volser(vlbl->f.volser);
 324
 325    run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 326    /* no return */
 327}
 328
 329static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
 330{
 331    LDL_VTOC *vlbl = (void *)sec; /* already read, 3rd block */
 332    char msg[4] = { '?', '.', '\n', '\0' };
 333
 334    sclp_print((mode == ECKD_CMS) ? "CMS" : "LDL");
 335    sclp_print(" version ");
 336    switch (vlbl->LDL_version) {
 337    case LDL1_VERSION:
 338        msg[0] = '1';
 339        break;
 340    case LDL2_VERSION:
 341        msg[0] = '2';
 342        break;
 343    default:
 344        msg[0] = ebc2asc[vlbl->LDL_version];
 345        msg[1] = '?';
 346        break;
 347    }
 348    sclp_print(msg);
 349    print_volser(vlbl->volser);
 350}
 351
 352static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
 353{
 354    block_number_t bmt_block_nr, s1b_block_nr;
 355    EckdLdlIpl1 *ipl1 = (void *)sec;
 356
 357    if (mode != ECKD_LDL_UNLABELED) {
 358        print_eckd_ldl_msg(mode);
 359    }
 360
 361    /* DO NOT read BootMap pointer (only one, xECKD) at block #2 */
 362
 363    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 364    read_block(0, sec, "Cannot read block 0 to grab boot info.");
 365    if (mode == ECKD_LDL_UNLABELED) {
 366        if (!magic_match(ipl1->bip.magic, ZIPL_MAGIC)) {
 367            return; /* not applicable layout */
 368        }
 369        sclp_print("unlabeled LDL.\n");
 370    }
 371    verify_boot_info(&ipl1->bip);
 372
 373    /* save pointer to Boot Map Table */
 374    bmt_block_nr = eckd_block_num(&ipl1->bip.bp.ipl.bm_ptr.eckd.bptr.chs);
 375
 376    /* save pointer to Stage1b Data */
 377    s1b_block_nr = eckd_block_num(&ipl1->stage1.seek[0].chs);
 378
 379    run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 380    /* no return */
 381}
 382
 383static void print_eckd_msg(void)
 384{
 385    char msg[] = "Using ECKD scheme (block size *****), ";
 386    char *p = &msg[34], *q = &msg[30];
 387    int n = virtio_get_block_size();
 388
 389    /* Fill in the block size and show up the message */
 390    if (n > 0 && n <= 99999) {
 391        while (n) {
 392            *p-- = '0' + (n % 10);
 393            n /= 10;
 394        }
 395        while (p >= q) {
 396            *p-- = ' ';
 397        }
 398    }
 399    sclp_print(msg);
 400}
 401
 402static void ipl_eckd(void)
 403{
 404    XEckdMbr *mbr = (void *)sec;
 405    LDL_VTOC *vlbl = (void *)sec;
 406
 407    print_eckd_msg();
 408
 409    /* Grab the MBR again */
 410    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 411    read_block(0, mbr, "Cannot read block 0 on DASD");
 412
 413    if (magic_match(mbr->magic, IPL1_MAGIC)) {
 414        ipl_eckd_cdl();         /* only returns in case of error */
 415        return;
 416    }
 417
 418    /* LDL/CMS? */
 419    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 420    read_block(2, vlbl, "Cannot read block 2");
 421
 422    if (magic_match(vlbl->magic, CMS1_MAGIC)) {
 423        ipl_eckd_ldl(ECKD_CMS); /* no return */
 424    }
 425    if (magic_match(vlbl->magic, LNX1_MAGIC)) {
 426        ipl_eckd_ldl(ECKD_LDL); /* no return */
 427    }
 428
 429    ipl_eckd_ldl(ECKD_LDL_UNLABELED); /* it still may return */
 430    /*
 431     * Ok, it is not a LDL by any means.
 432     * It still might be a CDL with zero record keys for IPL1 and IPL2
 433     */
 434    ipl_eckd_cdl();
 435}
 436
 437/***********************************************************************
 438 * IPL a SCSI disk
 439 */
 440
 441static void zipl_load_segment(ComponentEntry *entry)
 442{
 443    const int max_entries = (MAX_SECTOR_SIZE / sizeof(ScsiBlockPtr));
 444    ScsiBlockPtr *bprs = (void *)sec;
 445    const int bprs_size = sizeof(sec);
 446    block_number_t blockno;
 447    uint64_t address;
 448    int i;
 449    char err_msg[] = "zIPL failed to read BPRS at 0xZZZZZZZZZZZZZZZZ";
 450    char *blk_no = &err_msg[30]; /* where to print blockno in (those ZZs) */
 451
 452    blockno = entry->data.blockno;
 453    address = entry->compdat.load_addr;
 454
 455    debug_print_int("loading segment at block", blockno);
 456    debug_print_int("addr", address);
 457
 458    do {
 459        memset(bprs, FREE_SPACE_FILLER, bprs_size);
 460        fill_hex_val(blk_no, &blockno, sizeof(blockno));
 461        read_block(blockno, bprs, err_msg);
 462
 463        for (i = 0;; i++) {
 464            uint64_t *cur_desc = (void *)&bprs[i];
 465
 466            blockno = bprs[i].blockno;
 467            if (!blockno) {
 468                break;
 469            }
 470
 471            /* we need the updated blockno for the next indirect entry in the
 472               chain, but don't want to advance address */
 473            if (i == (max_entries - 1)) {
 474                break;
 475            }
 476
 477            if (bprs[i].blockct == 0 && unused_space(&bprs[i + 1],
 478                sizeof(ScsiBlockPtr))) {
 479                /* This is a "continue" pointer.
 480                 * This ptr is the last one in the current script section.
 481                 * I.e. the next ptr must point to the unused memory area.
 482                 * The blockno is not zero, so the upper loop must continue
 483                 * reading next section of BPRS.
 484                 */
 485                break;
 486            }
 487            address = virtio_load_direct(cur_desc[0], cur_desc[1], 0,
 488                                         (void *)address);
 489            IPL_assert(address != -1, "zIPL load segment failed");
 490        }
 491    } while (blockno);
 492}
 493
 494/* Run a zipl program */
 495static void zipl_run(ScsiBlockPtr *pte)
 496{
 497    ComponentHeader *header;
 498    ComponentEntry *entry;
 499    uint8_t tmp_sec[MAX_SECTOR_SIZE];
 500
 501    read_block(pte->blockno, tmp_sec, "Cannot read header");
 502    header = (ComponentHeader *)tmp_sec;
 503
 504    IPL_assert(magic_match(tmp_sec, ZIPL_MAGIC), "No zIPL magic in header");
 505    IPL_assert(header->type == ZIPL_COMP_HEADER_IPL, "Bad header type");
 506
 507    dputs("start loading images\n");
 508
 509    /* Load image(s) into RAM */
 510    entry = (ComponentEntry *)(&header[1]);
 511    while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
 512           entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
 513
 514        /* We don't support secure boot yet, so we skip signature entries */
 515        if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
 516            entry++;
 517            continue;
 518        }
 519
 520        zipl_load_segment(entry);
 521
 522        entry++;
 523
 524        IPL_assert((uint8_t *)(&entry[1]) <= (tmp_sec + MAX_SECTOR_SIZE),
 525                   "Wrong entry value");
 526    }
 527
 528    IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC entry");
 529
 530    /* should not return */
 531    write_reset_psw(entry->compdat.load_psw);
 532    jump_to_IPL_code(0);
 533}
 534
 535static void ipl_scsi(void)
 536{
 537    ScsiMbr *mbr = (void *)sec;
 538    int program_table_entries = 0;
 539    BootMapTable *prog_table = (void *)sec;
 540    unsigned int loadparm = get_loadparm_index();
 541    bool valid_entries[MAX_BOOT_ENTRIES] = {false};
 542    size_t i;
 543
 544    /* Grab the MBR */
 545    memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 546    read_block(0, mbr, "Cannot read block 0");
 547
 548    if (!magic_match(mbr->magic, ZIPL_MAGIC)) {
 549        return;
 550    }
 551
 552    sclp_print("Using SCSI scheme.\n");
 553    debug_print_int("MBR Version", mbr->version_id);
 554    IPL_check(mbr->version_id == 1,
 555              "Unknown MBR layout version, assuming version 1");
 556    debug_print_int("program table", mbr->pt.blockno);
 557    IPL_assert(mbr->pt.blockno, "No Program Table");
 558
 559    /* Parse the program table */
 560    read_block(mbr->pt.blockno, sec, "Error reading Program Table");
 561    IPL_assert(magic_match(sec, ZIPL_MAGIC), "No zIPL magic in PT");
 562
 563    for (i = 0; i < MAX_BOOT_ENTRIES; i++) {
 564        if (prog_table->entry[i].scsi.blockno) {
 565            valid_entries[i] = true;
 566            program_table_entries++;
 567        }
 568    }
 569
 570    debug_print_int("program table entries", program_table_entries);
 571    IPL_assert(program_table_entries != 0, "Empty Program Table");
 572
 573    if (menu_is_enabled_enum()) {
 574        loadparm = menu_get_enum_boot_index(valid_entries);
 575    }
 576
 577    debug_print_int("loadparm", loadparm);
 578    IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
 579               " maximum number of boot entries allowed");
 580
 581    zipl_run(&prog_table->entry[loadparm].scsi); /* no return */
 582}
 583
 584/***********************************************************************
 585 * IPL El Torito ISO9660 image or DVD
 586 */
 587
 588static bool is_iso_bc_entry_compatible(IsoBcSection *s)
 589{
 590    uint8_t *magic_sec = (uint8_t *)(sec + ISO_SECTOR_SIZE);
 591
 592    if (s->unused || !s->sector_count) {
 593        return false;
 594    }
 595    read_iso_sector(bswap32(s->load_rba), magic_sec,
 596                    "Failed to read image sector 0");
 597
 598    /* Checking bytes 8 - 32 for S390 Linux magic */
 599    return !memcmp(magic_sec + 8, linux_s390_magic, 24);
 600}
 601
 602/* Location of the current sector of the directory */
 603static uint32_t sec_loc[ISO9660_MAX_DIR_DEPTH];
 604/* Offset in the current sector of the directory */
 605static uint32_t sec_offset[ISO9660_MAX_DIR_DEPTH];
 606/* Remained directory space in bytes */
 607static uint32_t dir_rem[ISO9660_MAX_DIR_DEPTH];
 608
 609static inline uint32_t iso_get_file_size(uint32_t load_rba)
 610{
 611    IsoVolDesc *vd = (IsoVolDesc *)sec;
 612    IsoDirHdr *cur_record = &vd->vd.primary.rootdir;
 613    uint8_t *temp = sec + ISO_SECTOR_SIZE;
 614    int level = 0;
 615
 616    read_iso_sector(ISO_PRIMARY_VD_SECTOR, sec,
 617                    "Failed to read ISO primary descriptor");
 618    sec_loc[0] = iso_733_to_u32(cur_record->ext_loc);
 619    dir_rem[0] = 0;
 620    sec_offset[0] = 0;
 621
 622    while (level >= 0) {
 623        IPL_assert(sec_offset[level] <= ISO_SECTOR_SIZE,
 624                   "Directory tree structure violation");
 625
 626        cur_record = (IsoDirHdr *)(temp + sec_offset[level]);
 627
 628        if (sec_offset[level] == 0) {
 629            read_iso_sector(sec_loc[level], temp,
 630                            "Failed to read ISO directory");
 631            if (dir_rem[level] == 0) {
 632                /* Skip self and parent records */
 633                dir_rem[level] = iso_733_to_u32(cur_record->data_len) -
 634                                 cur_record->dr_len;
 635                sec_offset[level] += cur_record->dr_len;
 636
 637                cur_record = (IsoDirHdr *)(temp + sec_offset[level]);
 638                dir_rem[level] -= cur_record->dr_len;
 639                sec_offset[level] += cur_record->dr_len;
 640                continue;
 641            }
 642        }
 643
 644        if (!cur_record->dr_len || sec_offset[level] == ISO_SECTOR_SIZE) {
 645            /* Zero-padding and/or the end of current sector */
 646            dir_rem[level] -= ISO_SECTOR_SIZE - sec_offset[level];
 647            sec_offset[level] = 0;
 648            sec_loc[level]++;
 649        } else {
 650            /* The directory record is valid */
 651            if (load_rba == iso_733_to_u32(cur_record->ext_loc)) {
 652                return iso_733_to_u32(cur_record->data_len);
 653            }
 654
 655            dir_rem[level] -= cur_record->dr_len;
 656            sec_offset[level] += cur_record->dr_len;
 657
 658            if (cur_record->file_flags & 0x2) {
 659                /* Subdirectory */
 660                if (level == ISO9660_MAX_DIR_DEPTH - 1) {
 661                    sclp_print("ISO-9660 directory depth limit exceeded\n");
 662                } else {
 663                    level++;
 664                    sec_loc[level] = iso_733_to_u32(cur_record->ext_loc);
 665                    sec_offset[level] = 0;
 666                    dir_rem[level] = 0;
 667                    continue;
 668                }
 669            }
 670        }
 671
 672        if (dir_rem[level] == 0) {
 673            /* Nothing remaining */
 674            level--;
 675            read_iso_sector(sec_loc[level], temp,
 676                            "Failed to read ISO directory");
 677        }
 678    }
 679
 680    return 0;
 681}
 682
 683static void load_iso_bc_entry(IsoBcSection *load)
 684{
 685    IsoBcSection s = *load;
 686    /*
 687     * According to spec, extent for each file
 688     * is padded and ISO_SECTOR_SIZE bytes aligned
 689     */
 690    uint32_t blks_to_load = bswap16(s.sector_count) >> ET_SECTOR_SHIFT;
 691    uint32_t real_size = iso_get_file_size(bswap32(s.load_rba));
 692
 693    if (real_size) {
 694        /* Round up blocks to load */
 695        blks_to_load = (real_size + ISO_SECTOR_SIZE - 1) / ISO_SECTOR_SIZE;
 696        sclp_print("ISO boot image size verified\n");
 697    } else {
 698        sclp_print("ISO boot image size could not be verified\n");
 699    }
 700
 701    read_iso_boot_image(bswap32(s.load_rba),
 702                        (void *)((uint64_t)bswap16(s.load_segment)),
 703                        blks_to_load);
 704
 705    jump_to_low_kernel();
 706}
 707
 708static uint32_t find_iso_bc(void)
 709{
 710    IsoVolDesc *vd = (IsoVolDesc *)sec;
 711    uint32_t block_num = ISO_PRIMARY_VD_SECTOR;
 712
 713    if (virtio_read_many(block_num++, sec, 1)) {
 714        /* If primary vd cannot be read, there is no boot catalog */
 715        return 0;
 716    }
 717
 718    while (is_iso_vd_valid(vd) && vd->type != VOL_DESC_TERMINATOR) {
 719        if (vd->type == VOL_DESC_TYPE_BOOT) {
 720            IsoVdElTorito *et = &vd->vd.boot;
 721
 722            if (!memcmp(&et->el_torito[0], el_torito_magic, 32)) {
 723                return bswap32(et->bc_offset);
 724            }
 725        }
 726        read_iso_sector(block_num++, sec,
 727                        "Failed to read ISO volume descriptor");
 728    }
 729
 730    return 0;
 731}
 732
 733static IsoBcSection *find_iso_bc_entry(void)
 734{
 735    IsoBcEntry *e = (IsoBcEntry *)sec;
 736    uint32_t offset = find_iso_bc();
 737    int i;
 738    unsigned int loadparm = get_loadparm_index();
 739
 740    if (!offset) {
 741        return NULL;
 742    }
 743
 744    read_iso_sector(offset, sec, "Failed to read El Torito boot catalog");
 745
 746    if (!is_iso_bc_valid(e)) {
 747        /* The validation entry is mandatory */
 748        panic("No valid boot catalog found!\n");
 749        return NULL;
 750    }
 751
 752    /*
 753     * Each entry has 32 bytes size, so one sector cannot contain > 64 entries.
 754     * We consider only boot catalogs with no more than 64 entries.
 755     */
 756    for (i = 1; i < ISO_BC_ENTRY_PER_SECTOR; i++) {
 757        if (e[i].id == ISO_BC_BOOTABLE_SECTION) {
 758            if (is_iso_bc_entry_compatible(&e[i].body.sect)) {
 759                if (loadparm <= 1) {
 760                    /* found, default, or unspecified */
 761                    return &e[i].body.sect;
 762                }
 763                loadparm--;
 764            }
 765        }
 766    }
 767
 768    panic("No suitable boot entry found on ISO-9660 media!\n");
 769
 770    return NULL;
 771}
 772
 773static void ipl_iso_el_torito(void)
 774{
 775    IsoBcSection *s = find_iso_bc_entry();
 776
 777    if (s) {
 778        load_iso_bc_entry(s);
 779        /* no return */
 780    }
 781}
 782
 783/***********************************************************************
 784 * Bus specific IPL sequences
 785 */
 786
 787static void zipl_load_vblk(void)
 788{
 789    if (virtio_guessed_disk_nature()) {
 790        virtio_assume_iso9660();
 791    }
 792    ipl_iso_el_torito();
 793
 794    if (virtio_guessed_disk_nature()) {
 795        sclp_print("Using guessed DASD geometry.\n");
 796        virtio_assume_eckd();
 797    }
 798    ipl_eckd();
 799}
 800
 801static void zipl_load_vscsi(void)
 802{
 803    if (virtio_get_block_size() == VIRTIO_ISO_BLOCK_SIZE) {
 804        /* Is it an ISO image in non-CD drive? */
 805        ipl_iso_el_torito();
 806    }
 807
 808    sclp_print("Using guessed DASD geometry.\n");
 809    virtio_assume_eckd();
 810    ipl_eckd();
 811}
 812
 813/***********************************************************************
 814 * IPL starts here
 815 */
 816
 817void zipl_load(void)
 818{
 819    VDev *vdev = virtio_get_device();
 820
 821    if (vdev->is_cdrom) {
 822        ipl_iso_el_torito();
 823        panic("\n! Cannot IPL this ISO image !\n");
 824    }
 825
 826    if (virtio_get_device_type() == VIRTIO_ID_NET) {
 827        jump_to_IPL_code(vdev->netboot_start_addr);
 828    }
 829
 830    ipl_scsi();
 831
 832    switch (virtio_get_device_type()) {
 833    case VIRTIO_ID_BLOCK:
 834        zipl_load_vblk();
 835        break;
 836    case VIRTIO_ID_SCSI:
 837        zipl_load_vscsi();
 838        break;
 839    default:
 840        panic("\n! Unknown IPL device type !\n");
 841    }
 842
 843    sclp_print("zIPL load failed.\n");
 844}
 845