pc-bios/s390-ccw/bootmap.c

   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 */
  31 static uint8_t sec[MAX_SECTOR_SIZE*4] __attribute__((__aligned__(PAGE_SIZE)));
  32
  33 const 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  */
  40 const 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
  44 static 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
  57 static unsigned char _bprs[8*1024]; /* guessed "max" ECKD sector size */
  58 static const int max_bprs_entries = sizeof(_bprs) / sizeof(ExtEckdBlockPtr);
  59 static uint8_t _s2[MAX_SECTOR_SIZE * 3] __attribute__((__aligned__(PAGE_SIZE)));
  60 static void *s2_prev_blk = _s2;
  61 static void *s2_cur_blk = _s2 + MAX_SECTOR_SIZE;
  62 static void *s2_next_blk = _s2 + MAX_SECTOR_SIZE * 2;
  63
  64 static 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
  75 static void eckd_format_chs(ExtEckdBlockPtr *ptr,  bool ldipl,
  76                             uint64_t *c,
  77                             uint64_t *h,
  78                             uint64_t *s)
  79 {
  80     if (ldipl) {
  81         *c = ptr->ldptr.chs.cylinder;
  82         *h = ptr->ldptr.chs.head;
  83         *s = ptr->ldptr.chs.sector;
  84     } else {
  85         *c = ptr->bptr.chs.cylinder;
  86         *h = ptr->bptr.chs.head;
  87         *s = ptr->bptr.chs.sector;
  88     }
  89 }
  90
  91 static block_number_t eckd_chs_to_block(uint64_t c, uint64_t h, uint64_t s)
  92 {
  93     const uint64_t sectors = virtio_get_sectors();
  94     const uint64_t heads = virtio_get_heads();
  95     const uint64_t cylinder = c + ((h & 0xfff0) << 12);
  96     const uint64_t head = h & 0x000f;
  97     const block_number_t block = sectors * heads * cylinder
  98                                + sectors * head
  99                                + s - 1; /* block nr starts with zero */
 100     return block;
 101 }
 102
 103 static block_number_t eckd_block_num(EckdCHS *chs)
 104 {
 105     return eckd_chs_to_block(chs->cylinder, chs->head, chs->sector);
 106 }
 107
 108 static block_number_t gen_eckd_block_num(ExtEckdBlockPtr *ptr, bool ldipl)
 109 {
 110     uint64_t cyl, head, sec;
 111     eckd_format_chs(ptr, ldipl, &cyl, &head, &sec);
 112     return eckd_chs_to_block(cyl, head, sec);
 113 }
 114
 115 static bool eckd_valid_chs(uint64_t cyl, uint64_t head, uint64_t sector)
 116 {
 117     if (head >= virtio_get_heads()
 118         || sector > virtio_get_sectors()
 119         || sector <= 0) {
 120         return false;
 121     }
 122
 123     if (!virtio_guessed_disk_nature() &&
 124         eckd_chs_to_block(cyl, head, sector) >= virtio_get_blocks()) {
 125         return false;
 126     }
 127
 128     return true;
 129 }
 130
 131 static bool eckd_valid_address(ExtEckdBlockPtr *ptr, bool ldipl)
 132 {
 133     uint64_t cyl, head, sec;
 134     eckd_format_chs(ptr, ldipl, &cyl, &head, &sec);
 135     return eckd_valid_chs(cyl, head, sec);
 136 }
 137
 138 static block_number_t load_eckd_segments(block_number_t blk, bool ldipl,
 139                                          uint64_t *address)
 140 {
 141     block_number_t block_nr;
 142     int j, rc, count;
 143     BootMapPointer *bprs = (void *)_bprs;
 144     bool more_data;
 145
 146     memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
 147     read_block(blk, bprs, "BPRS read failed");
 148
 149     do {
 150         more_data = false;
 151         for (j = 0;; j++) {
 152             block_nr = gen_eckd_block_num(&bprs[j].xeckd, ldipl);
 153             if (is_null_block_number(block_nr)) { /* end of chunk */
 154                 break;
 155             }
 156
 157             /* we need the updated blockno for the next indirect entry
 158              * in the chain, but don't want to advance address
 159              */
 160             if (j == (max_bprs_entries - 1)) {
 161                 break;
 162             }
 163
 164             /* List directed pointer does not store block size */
 165             IPL_assert(ldipl || block_size_ok(bprs[j].xeckd.bptr.size),
 166                        "bad chunk block size");
 167
 168             if (!eckd_valid_address(&bprs[j].xeckd, ldipl)) {
 169                 /*
 170                  * If an invalid address is found during LD-IPL then break and
 171                  * retry as CCW
 172                  */
 173                 IPL_assert(ldipl, "bad chunk ECKD addr");
 174                 break;
 175             }
 176
 177             if (ldipl) {
 178                 count = bprs[j].xeckd.ldptr.count;
 179             } else {
 180                 count = bprs[j].xeckd.bptr.count;
 181             }
 182
 183             if (count == 0 && unused_space(&bprs[j + 1],
 184                 sizeof(EckdBlockPtr))) {
 185                 /* This is a "continue" pointer.
 186                  * This ptr should be the last one in the current
 187                  * script section.
 188                  * I.e. the next ptr must point to the unused memory area
 189                  */
 190                 memset(_bprs, FREE_SPACE_FILLER, sizeof(_bprs));
 191                 read_block(block_nr, bprs, "BPRS continuation read failed");
 192                 more_data = true;
 193                 break;
 194             }
 195
 196             /* Load (count+1) blocks of code at (block_nr)
 197              * to memory (address).
 198              */
 199             rc = virtio_read_many(block_nr, (void *)(*address), count + 1);
 200             IPL_assert(rc == 0, "code chunk read failed");
 201
 202             *address += (count + 1) * virtio_get_block_size();
 203         }
 204     } while (more_data);
 205     return block_nr;
 206 }
 207
 208 static bool find_zipl_boot_menu_banner(int *offset)
 209 {
 210     int i;
 211
 212     /* Menu banner starts with "zIPL" */
 213     for (i = 0; i <= virtio_get_block_size() - 4; i++) {
 214         if (magic_match(s2_cur_blk + i, ZIPL_MAGIC_EBCDIC)) {
 215             *offset = i;
 216             return true;
 217         }
 218     }
 219
 220     return false;
 221 }
 222
 223 static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
 224 {
 225     block_number_t cur_block_nr;
 226     block_number_t prev_block_nr = 0;
 227     block_number_t next_block_nr = 0;
 228     EckdStage1b *s1b = (void *)sec;
 229     int banner_offset;
 230     int i;
 231
 232     /* Get Stage1b data */
 233     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 234     read_block(s1b_block_nr, s1b, "Cannot read stage1b boot loader");
 235
 236     memset(_s2, FREE_SPACE_FILLER, sizeof(_s2));
 237
 238     /* Get Stage2 data */
 239     for (i = 0; i < STAGE2_BLK_CNT_MAX; i++) {
 240         cur_block_nr = eckd_block_num(&s1b->seek[i].chs);
 241
 242         if (!cur_block_nr || is_null_block_number(cur_block_nr)) {
 243             break;
 244         }
 245
 246         read_block(cur_block_nr, s2_cur_blk, "Cannot read stage2 boot loader");
 247
 248         if (find_zipl_boot_menu_banner(&banner_offset)) {
 249             /*
 250              * Load the adjacent blocks to account for the
 251              * possibility of menu data spanning multiple blocks.
 252              */
 253             if (prev_block_nr) {
 254                 read_block(prev_block_nr, s2_prev_blk,
 255                            "Cannot read stage2 boot loader");
 256             }
 257
 258             if (i + 1 < STAGE2_BLK_CNT_MAX) {
 259                 next_block_nr = eckd_block_num(&s1b->seek[i + 1].chs);
 260             }
 261
 262             if (next_block_nr && !is_null_block_number(next_block_nr)) {
 263                 read_block(next_block_nr, s2_next_blk,
 264                            "Cannot read stage2 boot loader");
 265             }
 266
 267             return menu_get_zipl_boot_index(s2_cur_blk + banner_offset);
 268         }
 269
 270         prev_block_nr = cur_block_nr;
 271     }
 272
 273     sclp_print("No zipl boot menu data found. Booting default entry.");
 274     return 0;
 275 }
 276
 277 static void run_eckd_boot_script(block_number_t bmt_block_nr,
 278                                  block_number_t s1b_block_nr)
 279 {
 280     int i;
 281     unsigned int loadparm = get_loadparm_index();
 282     block_number_t block_nr;
 283     uint64_t address;
 284     BootMapTable *bmt = (void *)sec;
 285     BootMapScript *bms = (void *)sec;
 286     /* The S1B block number is NULL_BLOCK_NR if and only if it's an LD-IPL */
 287     bool ldipl = (s1b_block_nr == NULL_BLOCK_NR);
 288
 289     if (menu_is_enabled_zipl() && !ldipl) {
 290         loadparm = eckd_get_boot_menu_index(s1b_block_nr);
 291     }
 292
 293     debug_print_int("loadparm", loadparm);
 294     IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
 295                " maximum number of boot entries allowed");
 296
 297     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 298     read_block(bmt_block_nr, sec, "Cannot read Boot Map Table");
 299
 300     block_nr = gen_eckd_block_num(&bmt->entry[loadparm].xeckd, ldipl);
 301     IPL_assert(block_nr != -1, "Cannot find Boot Map Table Entry");
 302
 303     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 304     read_block(block_nr, sec, "Cannot read Boot Map Script");
 305
 306     for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD ||
 307                 bms->entry[i].type == BOOT_SCRIPT_SIGNATURE; i++) {
 308
 309         /* We don't support secure boot yet, so we skip signature entries */
 310         if (bms->entry[i].type == BOOT_SCRIPT_SIGNATURE) {
 311             continue;
 312         }
 313
 314         address = bms->entry[i].address.load_address;
 315         block_nr = gen_eckd_block_num(&bms->entry[i].blkptr.xeckd, ldipl);
 316
 317         do {
 318             block_nr = load_eckd_segments(block_nr, ldipl, &address);
 319         } while (block_nr != -1);
 320     }
 321
 322     if (ldipl && bms->entry[i].type != BOOT_SCRIPT_EXEC) {
 323         /* Abort LD-IPL and retry as CCW-IPL */
 324         return;
 325     }
 326
 327     IPL_assert(bms->entry[i].type == BOOT_SCRIPT_EXEC,
 328                "Unknown script entry type");
 329     write_reset_psw(bms->entry[i].address.load_address); /* no return */
 330     jump_to_IPL_code(0); /* no return */
 331 }
 332
 333 static void ipl_eckd_cdl(void)
 334 {
 335     XEckdMbr *mbr;
 336     EckdCdlIpl2 *ipl2 = (void *)sec;
 337     IplVolumeLabel *vlbl = (void *)sec;
 338     block_number_t bmt_block_nr, s1b_block_nr;
 339
 340     /* we have just read the block #0 and recognized it as "IPL1" */
 341     sclp_print("CDL\n");
 342
 343     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 344     read_block(1, ipl2, "Cannot read IPL2 record at block 1");
 345
 346     mbr = &ipl2->mbr;
 347     if (!magic_match(mbr, ZIPL_MAGIC)) {
 348         sclp_print("No zIPL section in IPL2 record.\n");
 349         return;
 350     }
 351     if (!block_size_ok(mbr->blockptr.xeckd.bptr.size)) {
 352         sclp_print("Bad block size in zIPL section of IPL2 record.\n");
 353         return;
 354     }
 355     if (mbr->dev_type != DEV_TYPE_ECKD) {
 356         sclp_print("Non-ECKD device type in zIPL section of IPL2 record.\n");
 357         return;
 358     }
 359
 360     /* save pointer to Boot Map Table */
 361     bmt_block_nr = eckd_block_num(&mbr->blockptr.xeckd.bptr.chs);
 362
 363     /* save pointer to Stage1b Data */
 364     s1b_block_nr = eckd_block_num(&ipl2->stage1.seek[0].chs);
 365
 366     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 367     read_block(2, vlbl, "Cannot read Volume Label at block 2");
 368     if (!magic_match(vlbl->key, VOL1_MAGIC)) {
 369         sclp_print("Invalid magic of volume label block.\n");
 370         return;
 371     }
 372     if (!magic_match(vlbl->f.key, VOL1_MAGIC)) {
 373         sclp_print("Invalid magic of volser block.\n");
 374         return;
 375     }
 376     print_volser(vlbl->f.volser);
 377
 378     run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 379     /* no return */
 380 }
 381
 382 static void print_eckd_ldl_msg(ECKD_IPL_mode_t mode)
 383 {
 384     LDL_VTOC *vlbl = (void *)sec; /* already read, 3rd block */
 385     char msg[4] = { '?', '.', '\n', '\0' };
 386
 387     sclp_print((mode == ECKD_CMS) ? "CMS" : "LDL");
 388     sclp_print(" version ");
 389     switch (vlbl->LDL_version) {
 390     case LDL1_VERSION:
 391         msg[0] = '1';
 392         break;
 393     case LDL2_VERSION:
 394         msg[0] = '2';
 395         break;
 396     default:
 397         msg[0] = ebc2asc[vlbl->LDL_version];
 398         msg[1] = '?';
 399         break;
 400     }
 401     sclp_print(msg);
 402     print_volser(vlbl->volser);
 403 }
 404
 405 static void ipl_eckd_ldl(ECKD_IPL_mode_t mode)
 406 {
 407     block_number_t bmt_block_nr, s1b_block_nr;
 408     EckdLdlIpl1 *ipl1 = (void *)sec;
 409
 410     if (mode != ECKD_LDL_UNLABELED) {
 411         print_eckd_ldl_msg(mode);
 412     }
 413
 414     /* DO NOT read BootMap pointer (only one, xECKD) at block #2 */
 415
 416     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 417     read_block(0, sec, "Cannot read block 0 to grab boot info.");
 418     if (mode == ECKD_LDL_UNLABELED) {
 419         if (!magic_match(ipl1->bip.magic, ZIPL_MAGIC)) {
 420             return; /* not applicable layout */
 421         }
 422         sclp_print("unlabeled LDL.\n");
 423     }
 424     verify_boot_info(&ipl1->bip);
 425
 426     /* save pointer to Boot Map Table */
 427     bmt_block_nr = eckd_block_num(&ipl1->bip.bp.ipl.bm_ptr.eckd.bptr.chs);
 428
 429     /* save pointer to Stage1b Data */
 430     s1b_block_nr = eckd_block_num(&ipl1->stage1.seek[0].chs);
 431
 432     run_eckd_boot_script(bmt_block_nr, s1b_block_nr);
 433     /* no return */
 434 }
 435
 436 static block_number_t eckd_find_bmt(ExtEckdBlockPtr *ptr)
 437 {
 438     block_number_t blockno;
 439     uint8_t tmp_sec[MAX_SECTOR_SIZE];
 440     BootRecord *br;
 441
 442     blockno = gen_eckd_block_num(ptr, 0);
 443     read_block(blockno, tmp_sec, "Cannot read boot record");
 444     br = (BootRecord *)tmp_sec;
 445     if (!magic_match(br->magic, ZIPL_MAGIC)) {
 446         /* If the boot record is invalid, return and try CCW-IPL instead */
 447         return NULL_BLOCK_NR;
 448     }
 449
 450     return gen_eckd_block_num(&br->pgt.xeckd, 1);
 451 }
 452
 453 static void print_eckd_msg(void)
 454 {
 455     char msg[] = "Using ECKD scheme (block size *****), ";
 456     char *p = &msg[34], *q = &msg[30];
 457     int n = virtio_get_block_size();
 458
 459     /* Fill in the block size and show up the message */
 460     if (n > 0 && n <= 99999) {
 461         while (n) {
 462             *p-- = '0' + (n % 10);
 463             n /= 10;
 464         }
 465         while (p >= q) {
 466             *p-- = ' ';
 467         }
 468     }
 469     sclp_print(msg);
 470 }
 471
 472 static void ipl_eckd(void)
 473 {
 474     IplVolumeLabel *vlbl = (void *)sec;
 475     LDL_VTOC *vtoc = (void *)sec;
 476     block_number_t ldipl_bmt; /* Boot Map Table for List-Directed IPL */
 477
 478     print_eckd_msg();
 479
 480     /* Block 2 can contain either the CDL VOL1 label or the LDL VTOC */
 481     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 482     read_block(2, vlbl, "Cannot read block 2");
 483
 484     /*
 485      * First check for a list-directed-format pointer which would
 486      * supersede the CCW pointer.
 487      */
 488     if (eckd_valid_address((ExtEckdBlockPtr *)&vlbl->f.br, 0)) {
 489         ldipl_bmt = eckd_find_bmt((ExtEckdBlockPtr *)&vlbl->f.br);
 490         if (ldipl_bmt) {
 491             sclp_print("List-Directed\n");
 492             /* LD-IPL does not use the S1B bock, just make it NULL */
 493             run_eckd_boot_script(ldipl_bmt, NULL_BLOCK_NR);
 494             /* Only return in error, retry as CCW-IPL */
 495             sclp_print("Retrying IPL ");
 496             print_eckd_msg();
 497         }
 498         memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 499         read_block(2, vtoc, "Cannot read block 2");
 500     }
 501
 502     /* Not list-directed */
 503     if (magic_match(vtoc->magic, VOL1_MAGIC)) {
 504         ipl_eckd_cdl(); /* may return in error */
 505     }
 506
 507     if (magic_match(vtoc->magic, CMS1_MAGIC)) {
 508         ipl_eckd_ldl(ECKD_CMS); /* no return */
 509     }
 510     if (magic_match(vtoc->magic, LNX1_MAGIC)) {
 511         ipl_eckd_ldl(ECKD_LDL); /* no return */
 512     }
 513
 514     ipl_eckd_ldl(ECKD_LDL_UNLABELED); /* it still may return */
 515     /*
 516      * Ok, it is not a LDL by any means.
 517      * It still might be a CDL with zero record keys for IPL1 and IPL2
 518      */
 519     ipl_eckd_cdl();
 520 }
 521
 522 /***********************************************************************
 523  * IPL a SCSI disk
 524  */
 525
 526 static void zipl_load_segment(ComponentEntry *entry)
 527 {
 528     const int max_entries = (MAX_SECTOR_SIZE / sizeof(ScsiBlockPtr));
 529     ScsiBlockPtr *bprs = (void *)sec;
 530     const int bprs_size = sizeof(sec);
 531     block_number_t blockno;
 532     uint64_t address;
 533     int i;
 534     char err_msg[] = "zIPL failed to read BPRS at 0xZZZZZZZZZZZZZZZZ";
 535     char *blk_no = &err_msg[30]; /* where to print blockno in (those ZZs) */
 536
 537     blockno = entry->data.blockno;
 538     address = entry->compdat.load_addr;
 539
 540     debug_print_int("loading segment at block", blockno);
 541     debug_print_int("addr", address);
 542
 543     do {
 544         memset(bprs, FREE_SPACE_FILLER, bprs_size);
 545         fill_hex_val(blk_no, &blockno, sizeof(blockno));
 546         read_block(blockno, bprs, err_msg);
 547
 548         for (i = 0;; i++) {
 549             uint64_t *cur_desc = (void *)&bprs[i];
 550
 551             blockno = bprs[i].blockno;
 552             if (!blockno) {
 553                 break;
 554             }
 555
 556             /* we need the updated blockno for the next indirect entry in the
 557                chain, but don't want to advance address */
 558             if (i == (max_entries - 1)) {
 559                 break;
 560             }
 561
 562             if (bprs[i].blockct == 0 && unused_space(&bprs[i + 1],
 563                 sizeof(ScsiBlockPtr))) {
 564                 /* This is a "continue" pointer.
 565                  * This ptr is the last one in the current script section.
 566                  * I.e. the next ptr must point to the unused memory area.
 567                  * The blockno is not zero, so the upper loop must continue
 568                  * reading next section of BPRS.
 569                  */
 570                 break;
 571             }
 572             address = virtio_load_direct(cur_desc[0], cur_desc[1], 0,
 573                                          (void *)address);
 574             IPL_assert(address != -1, "zIPL load segment failed");
 575         }
 576     } while (blockno);
 577 }
 578
 579 /* Run a zipl program */
 580 static void zipl_run(ScsiBlockPtr *pte)
 581 {
 582     ComponentHeader *header;
 583     ComponentEntry *entry;
 584     uint8_t tmp_sec[MAX_SECTOR_SIZE];
 585
 586     read_block(pte->blockno, tmp_sec, "Cannot read header");
 587     header = (ComponentHeader *)tmp_sec;
 588
 589     IPL_assert(magic_match(tmp_sec, ZIPL_MAGIC), "No zIPL magic in header");
 590     IPL_assert(header->type == ZIPL_COMP_HEADER_IPL, "Bad header type");
 591
 592     dputs("start loading images\n");
 593
 594     /* Load image(s) into RAM */
 595     entry = (ComponentEntry *)(&header[1]);
 596     while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
 597            entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
 598
 599         /* We don't support secure boot yet, so we skip signature entries */
 600         if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
 601             entry++;
 602             continue;
 603         }
 604
 605         zipl_load_segment(entry);
 606
 607         entry++;
 608
 609         IPL_assert((uint8_t *)(&entry[1]) <= (tmp_sec + MAX_SECTOR_SIZE),
 610                    "Wrong entry value");
 611     }
 612
 613     IPL_assert(entry->component_type == ZIPL_COMP_ENTRY_EXEC, "No EXEC entry");
 614
 615     /* should not return */
 616     write_reset_psw(entry->compdat.load_psw);
 617     jump_to_IPL_code(0);
 618 }
 619
 620 static void ipl_scsi(void)
 621 {
 622     ScsiMbr *mbr = (void *)sec;
 623     int program_table_entries = 0;
 624     BootMapTable *prog_table = (void *)sec;
 625     unsigned int loadparm = get_loadparm_index();
 626     bool valid_entries[MAX_BOOT_ENTRIES] = {false};
 627     size_t i;
 628
 629     /* Grab the MBR */
 630     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
 631     read_block(0, mbr, "Cannot read block 0");
 632
 633     if (!magic_match(mbr->magic, ZIPL_MAGIC)) {
 634         return;
 635     }
 636
 637     sclp_print("Using SCSI scheme.\n");
 638     debug_print_int("MBR Version", mbr->version_id);
 639     IPL_check(mbr->version_id == 1,
 640               "Unknown MBR layout version, assuming version 1");
 641     debug_print_int("program table", mbr->pt.blockno);
 642     IPL_assert(mbr->pt.blockno, "No Program Table");
 643
 644     /* Parse the program table */
 645     read_block(mbr->pt.blockno, sec, "Error reading Program Table");
 646     IPL_assert(magic_match(sec, ZIPL_MAGIC), "No zIPL magic in PT");
 647
 648     for (i = 0; i < MAX_BOOT_ENTRIES; i++) {
 649         if (prog_table->entry[i].scsi.blockno) {
 650             valid_entries[i] = true;
 651             program_table_entries++;
 652         }
 653     }
 654
 655     debug_print_int("program table entries", program_table_entries);
 656     IPL_assert(program_table_entries != 0, "Empty Program Table");
 657
 658     if (menu_is_enabled_enum()) {
 659         loadparm = menu_get_enum_boot_index(valid_entries);
 660     }
 661
 662     debug_print_int("loadparm", loadparm);
 663     IPL_assert(loadparm < MAX_BOOT_ENTRIES, "loadparm value greater than"
 664                " maximum number of boot entries allowed");
 665
 666     zipl_run(&prog_table->entry[loadparm].scsi); /* no return */
 667 }
 668
 669 /***********************************************************************
 670  * IPL El Torito ISO9660 image or DVD
 671  */
 672
 673 static bool is_iso_bc_entry_compatible(IsoBcSection *s)
 674 {
 675     uint8_t *magic_sec = (uint8_t *)(sec + ISO_SECTOR_SIZE);
 676
 677     if (s->unused || !s->sector_count) {
 678         return false;
 679     }
 680     read_iso_sector(bswap32(s->load_rba), magic_sec,
 681                     "Failed to read image sector 0");
 682
 683     /* Checking bytes 8 - 32 for S390 Linux magic */
 684     return !memcmp(magic_sec + 8, linux_s390_magic, 24);
 685 }
 686
 687 /* Location of the current sector of the directory */
 688 static uint32_t sec_loc[ISO9660_MAX_DIR_DEPTH];
 689 /* Offset in the current sector of the directory */
 690 static uint32_t sec_offset[ISO9660_MAX_DIR_DEPTH];
 691 /* Remained directory space in bytes */
 692 static uint32_t dir_rem[ISO9660_MAX_DIR_DEPTH];
 693
 694 static inline uint32_t iso_get_file_size(uint32_t load_rba)
 695 {
 696     IsoVolDesc *vd = (IsoVolDesc *)sec;
 697     IsoDirHdr *cur_record = &vd->vd.primary.rootdir;
 698     uint8_t *temp = sec + ISO_SECTOR_SIZE;
 699     int level = 0;
 700
 701     read_iso_sector(ISO_PRIMARY_VD_SECTOR, sec,
 702                     "Failed to read ISO primary descriptor");
 703     sec_loc[0] = iso_733_to_u32(cur_record->ext_loc);
 704     dir_rem[0] = 0;
 705     sec_offset[0] = 0;
 706
 707     while (level >= 0) {
 708         IPL_assert(sec_offset[level] <= ISO_SECTOR_SIZE,
 709                    "Directory tree structure violation");
 710
 711         cur_record = (IsoDirHdr *)(temp + sec_offset[level]);
 712
 713         if (sec_offset[level] == 0) {
 714             read_iso_sector(sec_loc[level], temp,
 715                             "Failed to read ISO directory");
 716             if (dir_rem[level] == 0) {
 717                 /* Skip self and parent records */
 718                 dir_rem[level] = iso_733_to_u32(cur_record->data_len) -
 719                                  cur_record->dr_len;
 720                 sec_offset[level] += cur_record->dr_len;
 721
 722                 cur_record = (IsoDirHdr *)(temp + sec_offset[level]);
 723                 dir_rem[level] -= cur_record->dr_len;
 724                 sec_offset[level] += cur_record->dr_len;
 725                 continue;
 726             }
 727         }
 728
 729         if (!cur_record->dr_len || sec_offset[level] == ISO_SECTOR_SIZE) {
 730             /* Zero-padding and/or the end of current sector */
 731             dir_rem[level] -= ISO_SECTOR_SIZE - sec_offset[level];
 732             sec_offset[level] = 0;
 733             sec_loc[level]++;
 734         } else {
 735             /* The directory record is valid */
 736             if (load_rba == iso_733_to_u32(cur_record->ext_loc)) {
 737                 return iso_733_to_u32(cur_record->data_len);
 738             }
 739
 740             dir_rem[level] -= cur_record->dr_len;
 741             sec_offset[level] += cur_record->dr_len;
 742
 743             if (cur_record->file_flags & 0x2) {
 744                 /* Subdirectory */
 745                 if (level == ISO9660_MAX_DIR_DEPTH - 1) {
 746                     sclp_print("ISO-9660 directory depth limit exceeded\n");
 747                 } else {
 748                     level++;
 749                     sec_loc[level] = iso_733_to_u32(cur_record->ext_loc);
 750                     sec_offset[level] = 0;
 751                     dir_rem[level] = 0;
 752                     continue;
 753                 }
 754             }
 755         }
 756
 757         if (dir_rem[level] == 0) {
 758             /* Nothing remaining */
 759             level--;
 760             read_iso_sector(sec_loc[level], temp,
 761                             "Failed to read ISO directory");
 762         }
 763     }
 764
 765     return 0;
 766 }
 767
 768 static void load_iso_bc_entry(IsoBcSection *load)
 769 {
 770     IsoBcSection s = *load;
 771     /*
 772      * According to spec, extent for each file
 773      * is padded and ISO_SECTOR_SIZE bytes aligned
 774      */
 775     uint32_t blks_to_load = bswap16(s.sector_count) >> ET_SECTOR_SHIFT;
 776     uint32_t real_size = iso_get_file_size(bswap32(s.load_rba));
 777
 778     if (real_size) {
 779         /* Round up blocks to load */
 780         blks_to_load = (real_size + ISO_SECTOR_SIZE - 1) / ISO_SECTOR_SIZE;
 781         sclp_print("ISO boot image size verified\n");
 782     } else {
 783         sclp_print("ISO boot image size could not be verified\n");
 784     }
 785
 786     read_iso_boot_image(bswap32(s.load_rba),
 787                         (void *)((uint64_t)bswap16(s.load_segment)),
 788                         blks_to_load);
 789
 790     jump_to_low_kernel();
 791 }
 792
 793 static uint32_t find_iso_bc(void)
 794 {
 795     IsoVolDesc *vd = (IsoVolDesc *)sec;
 796     uint32_t block_num = ISO_PRIMARY_VD_SECTOR;
 797
 798     if (virtio_read_many(block_num++, sec, 1)) {
 799         /* If primary vd cannot be read, there is no boot catalog */
 800         return 0;
 801     }
 802
 803     while (is_iso_vd_valid(vd) && vd->type != VOL_DESC_TERMINATOR) {
 804         if (vd->type == VOL_DESC_TYPE_BOOT) {
 805             IsoVdElTorito *et = &vd->vd.boot;
 806
 807             if (!memcmp(&et->el_torito[0], el_torito_magic, 32)) {
 808                 return bswap32(et->bc_offset);
 809             }
 810         }
 811         read_iso_sector(block_num++, sec,
 812                         "Failed to read ISO volume descriptor");
 813     }
 814
 815     return 0;
 816 }
 817
 818 static IsoBcSection *find_iso_bc_entry(void)
 819 {
 820     IsoBcEntry *e = (IsoBcEntry *)sec;
 821     uint32_t offset = find_iso_bc();
 822     int i;
 823     unsigned int loadparm = get_loadparm_index();
 824
 825     if (!offset) {
 826         return NULL;
 827     }
 828
 829     read_iso_sector(offset, sec, "Failed to read El Torito boot catalog");
 830
 831     if (!is_iso_bc_valid(e)) {
 832         /* The validation entry is mandatory */
 833         panic("No valid boot catalog found!\n");
 834         return NULL;
 835     }
 836
 837     /*
 838      * Each entry has 32 bytes size, so one sector cannot contain > 64 entries.
 839      * We consider only boot catalogs with no more than 64 entries.
 840      */
 841     for (i = 1; i < ISO_BC_ENTRY_PER_SECTOR; i++) {
 842         if (e[i].id == ISO_BC_BOOTABLE_SECTION) {
 843             if (is_iso_bc_entry_compatible(&e[i].body.sect)) {
 844                 if (loadparm <= 1) {
 845                     /* found, default, or unspecified */
 846                     return &e[i].body.sect;
 847                 }
 848                 loadparm--;
 849             }
 850         }
 851     }
 852
 853     panic("No suitable boot entry found on ISO-9660 media!\n");
 854
 855     return NULL;
 856 }
 857
 858 static void ipl_iso_el_torito(void)
 859 {
 860     IsoBcSection *s = find_iso_bc_entry();
 861
 862     if (s) {
 863         load_iso_bc_entry(s);
 864         /* no return */
 865     }
 866 }
 867
 868 /**
 869  * Detect whether we're trying to boot from an .ISO image.
 870  * These always have a signature string "CD001" at offset 0x8001.
 871  */
 872 static bool has_iso_signature(void)
 873 {
 874     int blksize = virtio_get_block_size();
 875
 876     if (!blksize || virtio_read(0x8000 / blksize, sec)) {
 877         return false;
 878     }
 879
 880     return !memcmp("CD001", &sec[1], 5);
 881 }
 882
 883 /***********************************************************************
 884  * Bus specific IPL sequences
 885  */
 886
 887 static void zipl_load_vblk(void)
 888 {
 889     int blksize = virtio_get_block_size();
 890
 891     if (blksize == VIRTIO_ISO_BLOCK_SIZE || has_iso_signature()) {
 892         if (blksize != VIRTIO_ISO_BLOCK_SIZE) {
 893             virtio_assume_iso9660();
 894         }
 895         ipl_iso_el_torito();
 896     }
 897
 898     if (blksize != VIRTIO_DASD_DEFAULT_BLOCK_SIZE) {
 899         sclp_print("Using guessed DASD geometry.\n");
 900         virtio_assume_eckd();
 901     }
 902     ipl_eckd();
 903 }
 904
 905 static void zipl_load_vscsi(void)
 906 {
 907     if (virtio_get_block_size() == VIRTIO_ISO_BLOCK_SIZE) {
 908         /* Is it an ISO image in non-CD drive? */
 909         ipl_iso_el_torito();
 910     }
 911
 912     sclp_print("Using guessed DASD geometry.\n");
 913     virtio_assume_eckd();
 914     ipl_eckd();
 915 }
 916
 917 /***********************************************************************
 918  * IPL starts here
 919  */
 920
 921 void zipl_load(void)
 922 {
 923     VDev *vdev = virtio_get_device();
 924
 925     if (vdev->is_cdrom) {
 926         ipl_iso_el_torito();
 927         panic("\n! Cannot IPL this ISO image !\n");
 928     }
 929
 930     if (virtio_get_device_type() == VIRTIO_ID_NET) {
 931         jump_to_IPL_code(vdev->netboot_start_addr);
 932     }
 933
 934     ipl_scsi();
 935
 936     switch (virtio_get_device_type()) {
 937     case VIRTIO_ID_BLOCK:
 938         zipl_load_vblk();
 939         break;
 940     case VIRTIO_ID_SCSI:
 941         zipl_load_vscsi();
 942         break;
 943     default:
 944         panic("\n! Unknown IPL device type !\n");
 945     }
 946
 947     sclp_print("zIPL load failed.\n");
 948 }