sys/boot/pc32/boot2/boot2.c

   1 /*
   2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * Copyright (c) 1998 Robert Nordier
  35  * All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms are freely
  38  * permitted provided that the above copyright notice and this
  39  * paragraph and the following disclaimer are duplicated in all
  40  * such forms.
  41  *
  42  * This software is provided "AS IS" and without any express or
  43  * implied warranties, including, without limitation, the implied
  44  * warranties of merchantability and fitness for a particular
  45  * purpose.
  46  *
  47  * $FreeBSD: src/sys/boot/i386/boot2/boot2.c,v 1.64 2003/08/25 23:28:31 obrien Exp $
  48  * $DragonFly: src/sys/boot/pc32/boot2/boot2.c,v 1.18 2008/09/13 11:45:45 corecode Exp $
  49  */
  50
  51 #define AOUT_H_FORCE32
  52 #include <sys/param.h>
  53 #ifdef DISKLABEL64
  54 #include <sys/disklabel64.h>
  55 #else
  56 #include <sys/disklabel32.h>
  57 #endif
  58 #include <sys/diskslice.h>
  59 #include <sys/diskmbr.h>
  60 #include <sys/dtype.h>
  61 #include <sys/dirent.h>
  62 #include <machine/bootinfo.h>
  63 #include <machine/elf.h>
  64 #include <machine/psl.h>
  65
  66 #include <stdarg.h>
  67
  68 #include <a.out.h>
  69
  70 #include <btxv86.h>
  71
  72 #ifdef DISKLABEL64
  73 #include "boot2_64.h"
  74 #else
  75 #include "boot2_32.h"
  76 #endif
  77 #include "boot2.h"
  78 #include "lib.h"
  79 #include "../bootasm.h"
  80
  81 #define SECOND          18      /* Circa that many ticks in a second. */
  82
  83 #define RBX_ASKNAME     0x0     /* -a */
  84 #define RBX_SINGLE      0x1     /* -s */
  85 #define RBX_DFLTROOT    0x5     /* -r */
  86 #define RBX_KDB         0x6     /* -d */
  87 #define RBX_CONFIG      0xa     /* -c */
  88 #define RBX_VERBOSE     0xb     /* -v */
  89 #define RBX_SERIAL      0xc     /* -h */
  90 #define RBX_CDROM       0xd     /* -C */
  91 #define RBX_GDB         0xf     /* -g */
  92 #define RBX_MUTE        0x10    /* -m */
  93 #define RBX_PAUSE       0x12    /* -p */
  94 #define RBX_NOINTR      0x1c    /* -n */
  95 #define RBX_VIDEO       0x1d    /* -V */
  96 #define RBX_PROBEKBD    0x1e    /* -P */
  97 /* 0x1f is reserved for the historical RB_BOOTINFO option */
  98
  99 #define RBF_MUTE        (1 << RBX_MUTE)
 100 #define RBF_SERIAL      (1 << RBX_SERIAL)
 101 #define RBF_VIDEO       (1 << RBX_VIDEO)
 102
 103 /* pass: -a, -s, -r, -d, -c, -v, -h, -C, -g, -m, -p, -V */
 104 #define RBX_MASK        0x2005ffff
 105
 106 #define PATH_CONFIG     "/boot.config"
 107 #define PATH_BOOT3      "/boot/loader"          /* /boot in root */
 108 #define PATH_BOOT3_ALT  "/loader"               /* /boot partition */
 109 #define PATH_KERNEL     "/kernel"
 110
 111 #define NDEV            3
 112 #define MEM_BASE        0x12
 113 #define MEM_EXT         0x15
 114 #define V86_CY(x)       ((x) & PSL_C)
 115 #define V86_ZR(x)       ((x) & PSL_Z)
 116
 117 #define DRV_HARD        0x80
 118 #define DRV_MASK        0x7f
 119
 120 #define TYPE_AD         0
 121 #define TYPE_DA         1
 122 #define TYPE_MAXHARD    TYPE_DA
 123 #define TYPE_FD         2
 124
 125 #define NOPT            12
 126
 127 #define INVALID_S       "Bad %s\n"
 128
 129 extern uint32_t _end;
 130
 131 static const char optstr[NOPT] = { "VhaCgmnPprsv" };
 132 static const unsigned char flags[NOPT] = {
 133     RBX_VIDEO,
 134     RBX_SERIAL,
 135     RBX_ASKNAME,
 136     RBX_CDROM,
 137     RBX_GDB,
 138     RBX_MUTE,
 139     RBX_NOINTR,
 140     RBX_PROBEKBD,
 141     RBX_PAUSE,
 142     RBX_DFLTROOT,
 143     RBX_SINGLE,
 144     RBX_VERBOSE
 145 };
 146
 147 static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
 148 static const unsigned char dev_maj[NDEV] = {30, 4, 2};
 149
 150 static struct dsk {
 151     unsigned drive;
 152     unsigned type;
 153     unsigned unit;
 154     unsigned slice;
 155     unsigned part;
 156     unsigned start;
 157     int init;
 158 } dsk;
 159
 160 static char cmd[512];
 161 static char kname[1024];
 162 static uint32_t opts = RBF_VIDEO;
 163 static struct bootinfo bootinfo;
 164
 165 /*
 166  * boot2 encapsulated ABI elements provided to *fsread.c
 167  *
 168  * NOTE: boot2_dmadat is extended by per-filesystem APIs
 169  */
 170 uint32_t fs_off;
 171 int     ls;
 172 struct boot2_dmadat *boot2_dmadat;
 173
 174 void exit(int);
 175 static void load(void);
 176 static int parse(void);
 177 static int dskprobe(void);
 178 static int xfsread(boot2_ino_t, void *, size_t);
 179 static uint32_t memsize(void);
 180 static int drvread(void *, unsigned, unsigned);
 181 static int keyhit(unsigned);
 182 static void xputc(int);
 183 static int xgetc(int);
 184 static int getc(int);
 185
 186 void
 187 memcpy(void *d, const void *s, int len)
 188 {
 189     char *dd = d;
 190     const char *ss = s;
 191
 192 #if 0
 193     if (dd < ss) {
 194         while (--len >= 0)
 195             *dd++ = *ss++;
 196     } else {
 197 #endif
 198         while (--len >= 0)
 199             dd[len] = ss[len];
 200 #if 0
 201     }
 202 #endif
 203 }
 204
 205 int
 206 strcmp(const char *s1, const char *s2)
 207 {
 208     for (; *s1 == *s2 && *s1; s1++, s2++)
 209         ;
 210     return ((int)((unsigned char)*s1 - (unsigned char)*s2));
 211 }
 212
 213 #if defined(UFS) && defined(HAMMERFS)
 214
 215 const struct boot2_fsapi *fsapi;
 216
 217 #elif defined(UFS)
 218
 219 #define fsapi   (&boot2_ufs_api)
 220
 221 #elif defined(HAMMERFS)
 222
 223 #define fsapi   (&boot2_hammer_api)
 224
 225 #endif
 226
 227 static int
 228 xfsread(boot2_ino_t inode, void *buf, size_t nbyte)
 229 {
 230     if ((size_t)fsapi->fsread(inode, buf, nbyte) != nbyte) {
 231         printf(INVALID_S, "format");
 232         return -1;
 233     }
 234     return 0;
 235 }
 236
 237 static inline uint32_t
 238 memsize(void)
 239 {
 240     v86.addr = MEM_EXT;
 241     v86.eax = 0x8800;
 242     v86int();
 243     return v86.eax;
 244 }
 245
 246 static inline void
 247 getstr(void)
 248 {
 249     char *s;
 250     int c;
 251
 252     s = cmd;
 253     for (;;) {
 254         switch (c = xgetc(0)) {
 255         case 0:
 256             break;
 257         case '\177':
 258         case '\b':
 259             if (s > cmd) {
 260                 s--;
 261                 printf("\b \b");
 262             }
 263             break;
 264         case '\n':
 265         case '\r':
 266             *s = 0;
 267             return;
 268         default:
 269             if (s - cmd < sizeof(cmd) - 1)
 270                 *s++ = c;
 271             putchar(c);
 272         }
 273     }
 274 }
 275
 276 static inline void
 277 putc(int c)
 278 {
 279     v86.addr = 0x10;
 280     v86.eax = 0xe00 | (c & 0xff);
 281     v86.ebx = 0x7;
 282     v86int();
 283 }
 284
 285 int
 286 main(void)
 287 {
 288     int autoboot;
 289     boot2_ino_t ino;
 290
 291     boot2_dmadat =
 292                 (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
 293     v86.ctl = V86_FLAGS;
 294     v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
 295     dsk.drive = *(uint8_t *)PTOV(MEM_BTX_USR_ARG);
 296     dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
 297     dsk.unit = dsk.drive & DRV_MASK;
 298     dsk.slice = *(uint8_t *)PTOV(MEM_BTX_USR_ARG + 1) + 1;
 299     bootinfo.bi_version = BOOTINFO_VERSION;
 300     bootinfo.bi_size = sizeof(bootinfo);
 301     bootinfo.bi_basemem = 0;    /* XXX will be filled by loader or kernel */
 302     bootinfo.bi_extmem = memsize();
 303     bootinfo.bi_memsizes_valid++;
 304
 305     autoboot = 1;
 306
 307     /*
 308      * Probe the default disk and process the configuration file if
 309      * successful.
 310      */
 311     if (dskprobe() == 0) {
 312         if ((ino = fsapi->fslookup(PATH_CONFIG)))
 313             fsapi->fsread(ino, cmd, sizeof(cmd));
 314     }
 315
 316     /*
 317      * Parse config file if present.  parse() will re-probe if necessary.
 318      */
 319     if (cmd[0]) {
 320         printf("%s: %s", PATH_CONFIG, cmd);
 321         if (parse())
 322             autoboot = 0;
 323         /* Do not process this command twice */
 324         *cmd = 0;
 325     }
 326
 327     /*
 328      * Setup our (serial) console after processing the config file.  If
 329      * the initialization fails, don't try to use the serial port.  This
 330      * can happen if the serial port is unmaped (happens on new laptops a lot).
 331      */
 332     if ((opts & (RBF_MUTE|RBF_SERIAL|RBF_VIDEO)) == 0)
 333         opts |= RBF_SERIAL|RBF_VIDEO;
 334     if (opts & RBF_SERIAL) {
 335         if (sio_init())
 336             opts = RBF_VIDEO;
 337     }
 338
 339
 340     /*
 341      * Try to exec stage 3 boot loader. If interrupted by a keypress,
 342      * or in case of failure, try to load a kernel directly instead.
 343      *
 344      * We have to try boot /boot/loader and /loader to support booting
 345      * from a /boot partition instead of a root partition.
 346      */
 347     if (autoboot && !*kname) {
 348         memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
 349         if (!keyhit(3*SECOND)) {
 350             load();
 351             memcpy(kname, PATH_BOOT3_ALT, sizeof(PATH_BOOT3_ALT));
 352             load();
 353             memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
 354         }
 355     }
 356
 357     /* Present the user with the boot2 prompt. */
 358
 359     for (;;) {
 360         printf("\nDragonFly boot\n"
 361                "%u:%s(%u,%c)%s: ",
 362                dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
 363                'a' + dsk.part, kname);
 364         if (!autoboot || keyhit(5*SECOND))
 365             getstr();
 366         else
 367             putchar('\n');
 368         autoboot = 0;
 369         if (parse())
 370             putchar('\a');
 371         else
 372             load();
 373     }
 374 }
 375
 376 /* XXX - Needed for btxld to link the boot2 binary; do not remove. */
 377 void
 378 exit(int x)
 379 {
 380 }
 381
 382 static void
 383 load(void)
 384 {
 385     union {
 386         struct exec ex;
 387         Elf32_Ehdr eh;
 388     } hdr;
 389     Elf32_Phdr ep[2];
 390     Elf32_Shdr es[2];
 391     caddr_t p;
 392     boot2_ino_t ino;
 393     uint32_t addr, x;
 394     int fmt, i, j;
 395
 396     if (!(ino = fsapi->fslookup(kname))) {
 397         if (!ls)
 398             printf("No %s\n", kname);
 399         return;
 400     }
 401     if (xfsread(ino, &hdr, sizeof(hdr)))
 402         return;
 403     if (N_GETMAGIC(hdr.ex) == ZMAGIC)
 404         fmt = 0;
 405     else if (IS_ELF(hdr.eh))
 406         fmt = 1;
 407     else {
 408         printf(INVALID_S, "format");
 409         return;
 410     }
 411     if (fmt == 0) {
 412         addr = hdr.ex.a_entry & 0xffffff;
 413         p = PTOV(addr);
 414         fs_off = PAGE_SIZE;
 415         if (xfsread(ino, p, hdr.ex.a_text))
 416             return;
 417         p += roundup2(hdr.ex.a_text, PAGE_SIZE);
 418         if (xfsread(ino, p, hdr.ex.a_data))
 419             return;
 420         p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
 421         bootinfo.bi_symtab = VTOP(p);
 422         memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
 423         p += sizeof(hdr.ex.a_syms);
 424         if (hdr.ex.a_syms) {
 425             if (xfsread(ino, p, hdr.ex.a_syms))
 426                 return;
 427             p += hdr.ex.a_syms;
 428             if (xfsread(ino, p, sizeof(int)))
 429                 return;
 430             x = *(uint32_t *)p;
 431             p += sizeof(int);
 432             x -= sizeof(int);
 433             if (xfsread(ino, p, x))
 434                 return;
 435             p += x;
 436         }
 437     } else {
 438         fs_off = hdr.eh.e_phoff;
 439         for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
 440             if (xfsread(ino, ep + j, sizeof(ep[0])))
 441                 return;
 442             if (ep[j].p_type == PT_LOAD)
 443                 j++;
 444         }
 445         for (i = 0; i < 2; i++) {
 446             p = PTOV(ep[i].p_paddr & 0xffffff);
 447             fs_off = ep[i].p_offset;
 448             if (xfsread(ino, p, ep[i].p_filesz))
 449                 return;
 450         }
 451         p += roundup2(ep[1].p_memsz, PAGE_SIZE);
 452         bootinfo.bi_symtab = VTOP(p);
 453         if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
 454             fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
 455                 (hdr.eh.e_shstrndx + 1);
 456             if (xfsread(ino, &es, sizeof(es)))
 457                 return;
 458             for (i = 0; i < 2; i++) {
 459                 memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size));
 460                 p += sizeof(es[i].sh_size);
 461                 fs_off = es[i].sh_offset;
 462                 if (xfsread(ino, p, es[i].sh_size))
 463                     return;
 464                 p += es[i].sh_size;
 465             }
 466         }
 467         addr = hdr.eh.e_entry & 0xffffff;
 468     }
 469     bootinfo.bi_esymtab = VTOP(p);
 470     bootinfo.bi_kernelname = VTOP(kname);
 471     bootinfo.bi_bios_dev = dsk.drive;
 472     __exec((caddr_t)addr, opts & RBX_MASK,
 473            MAKEBOOTDEV(dev_maj[dsk.type], 0, dsk.slice, dsk.unit, dsk.part),
 474            0, 0, 0, VTOP(&bootinfo));
 475 }
 476
 477 static int
 478 parse(void)
 479 {
 480     char *arg = cmd;
 481     char *p, *q;
 482     unsigned int drv;
 483     int c, i;
 484
 485     while ((c = *arg++)) {
 486         if (c == ' ' || c == '\t' || c == '\n')
 487             continue;
 488         for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++)
 489             ;
 490         if (*p)
 491             *p++ = 0;
 492         if (c == '-') {
 493             while ((c = *arg++)) {
 494                 for (i = NOPT - 1; i >= 0; --i) {
 495                     if (optstr[i] == c) {
 496                         opts ^= 1 << flags[i];
 497                         goto ok;
 498                     }
 499                 }
 500                 return(-1);
 501                 ok: ;   /* ugly but save space */
 502             }
 503             if (opts & (1 << RBX_PROBEKBD)) {
 504                 i = *(uint8_t *)PTOV(0x496) & 0x10;
 505                 if (!i) {
 506                     printf("NO KB\n");
 507                     opts |= RBF_VIDEO | RBF_SERIAL;
 508                 }
 509                 opts &= ~(1 << RBX_PROBEKBD);
 510             }
 511         } else {
 512             for (q = arg--; *q && *q != '('; q++);
 513             if (*q) {
 514                 drv = -1;
 515                 if (arg[1] == ':') {
 516                     drv = *arg - '0';
 517                     if (drv > 9)
 518                         return (-1);
 519                     arg += 2;
 520                 }
 521                 if (q - arg != 2)
 522                     return -1;
 523                 for (i = 0; arg[0] != dev_nm[i][0] ||
 524                             arg[1] != dev_nm[i][1]; i++)
 525                     if (i == NDEV - 1)
 526                         return -1;
 527                 dsk.type = i;
 528                 arg += 3;
 529                 dsk.unit = *arg - '0';
 530                 if (arg[1] != ',' || dsk.unit > 9)
 531                     return -1;
 532                 arg += 2;
 533                 dsk.slice = WHOLE_DISK_SLICE;
 534                 if (arg[1] == ',') {
 535                     dsk.slice = *arg - '0' + 1;
 536                     if (dsk.slice > NDOSPART)
 537                         return -1;
 538                     arg += 2;
 539                 }
 540                 if (arg[1] != ')')
 541                     return -1;
 542                 dsk.part = *arg - 'a';
 543                 if (dsk.part > 7)
 544                     return (-1);
 545                 arg += 2;
 546                 if (drv == -1)
 547                     drv = dsk.unit;
 548                 dsk.drive = (dsk.type <= TYPE_MAXHARD
 549                              ? DRV_HARD : 0) + drv;
 550             }
 551             if ((i = p - arg - !*(p - 1))) {
 552                 if ((size_t)i >= sizeof(kname))
 553                     return -1;
 554                 memcpy(kname, arg, i + 1);
 555             }
 556         }
 557         arg = p;
 558     }
 559     return dskprobe();
 560 }
 561
 562 static int
 563 dskprobe(void)
 564 {
 565     struct dos_partition *dp;
 566 #ifdef DISKLABEL64
 567     struct disklabel64 *d;
 568 #else
 569     struct disklabel32 *d;
 570 #endif
 571     char *sec;
 572     unsigned sl, i;
 573
 574     /*
 575      * Probe slice table
 576      */
 577     sec = boot2_dmadat->secbuf;
 578     dsk.start = 0;
 579     if (drvread(sec, DOSBBSECTOR, 1))
 580         return -1;
 581     dp = (void *)(sec + DOSPARTOFF);
 582     sl = dsk.slice;
 583     if (sl < BASE_SLICE) {
 584         for (i = 0; i < NDOSPART; i++)
 585             if (dp[i].dp_typ == DOSPTYP_386BSD &&
 586                 (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
 587                 sl = BASE_SLICE + i;
 588                 if (dp[i].dp_flag & 0x80 ||
 589                     dsk.slice == COMPATIBILITY_SLICE)
 590                     break;
 591             }
 592         if (dsk.slice == WHOLE_DISK_SLICE)
 593             dsk.slice = sl;
 594     }
 595     if (sl != WHOLE_DISK_SLICE) {
 596         if (sl != COMPATIBILITY_SLICE)
 597             dp += sl - BASE_SLICE;
 598         if (dp->dp_typ != DOSPTYP_386BSD) {
 599             printf(INVALID_S, "slice");
 600             return -1;
 601         }
 602         dsk.start = dp->dp_start;
 603     }
 604
 605     /*
 606      * Probe label and partition table
 607      */
 608 #ifdef DISKLABEL64
 609     if (drvread(sec, dsk.start, (sizeof(struct disklabel64) + 511) / 512))
 610             return -1;
 611     d = (void *)sec;
 612     if (d->d_magic != DISKMAGIC64) {
 613         printf(INVALID_S, "label");
 614         return -1;
 615     } else {
 616         if (dsk.part >= d->d_npartitions || d->d_partitions[dsk.part].p_bsize == 0) {
 617             printf(INVALID_S, "partition");
 618             return -1;
 619         }
 620         dsk.start += d->d_partitions[dsk.part].p_boffset / 512;
 621     }
 622 #else
 623     if (drvread(sec, dsk.start + LABELSECTOR32, 1))
 624             return -1;
 625     d = (void *)(sec + LABELOFFSET32);
 626     if (d->d_magic != DISKMAGIC32 || d->d_magic2 != DISKMAGIC32) {
 627         if (dsk.part != RAW_PART) {
 628             printf(INVALID_S, "label");
 629             return -1;
 630         }
 631     } else {
 632         if (!dsk.init) {
 633             if (d->d_type == DTYPE_SCSI)
 634                 dsk.type = TYPE_DA;
 635             dsk.init++;
 636         }
 637         if (dsk.part >= d->d_npartitions ||
 638             !d->d_partitions[dsk.part].p_size) {
 639             printf(INVALID_S, "partition");
 640             return -1;
 641         }
 642         dsk.start += d->d_partitions[dsk.part].p_offset;
 643         dsk.start -= d->d_partitions[RAW_PART].p_offset;
 644     }
 645 #endif
 646     /*
 647      * Probe filesystem
 648      */
 649 #if defined(UFS) && defined(HAMMERFS)
 650     if (boot2_hammer_api.fsinit() == 0) {
 651         fsapi = &boot2_hammer_api;
 652     } else if (boot2_ufs_api.fsinit() == 0) {
 653         fsapi = &boot2_ufs_api;
 654     } else {
 655         printf("fs probe failed\n");
 656         fsapi = &boot2_ufs_api;
 657         return -1;
 658     }
 659     return 0;
 660 #else
 661     return fsapi->fsinit();
 662 #endif
 663 }
 664
 665
 666 /*
 667  * Read from the probed disk.  We have established the slice and partition
 668  * base sector.
 669  */
 670 int
 671 dskread(void *buf, unsigned lba, unsigned nblk)
 672 {
 673     return drvread(buf, dsk.start + lba, nblk);
 674 }
 675
 676 /*
 677  * boot encapsulated ABI
 678  */
 679 void
 680 printf(const char *fmt,...)
 681 {
 682     va_list ap;
 683     char buf[10];
 684     char *s;
 685     unsigned u;
 686     int c;
 687
 688     va_start(ap, fmt);
 689     while ((c = *fmt++)) {
 690         if (c == '%') {
 691             c = *fmt++;
 692             switch (c) {
 693             case 'c':
 694                 putchar(va_arg(ap, int));
 695                 continue;
 696             case 's':
 697                 for (s = va_arg(ap, char *); *s; s++)
 698                     putchar(*s);
 699                 continue;
 700             case 'u':
 701                 u = va_arg(ap, unsigned);
 702                 s = buf;
 703                 do
 704                     *s++ = '0' + u % 10U;
 705                 while (u /= 10U);
 706                 while (--s >= buf)
 707                     putchar(*s);
 708                 continue;
 709             }
 710         }
 711         putchar(c);
 712     }
 713     va_end(ap);
 714 }
 715
 716 /*
 717  * boot encapsulated ABI
 718  */
 719 void
 720 putchar(int c)
 721 {
 722     if (c == '\n')
 723         xputc('\r');
 724     xputc(c);
 725 }
 726
 727 /*
 728  * boot encapsulated ABI
 729  */
 730 int
 731 drvread(void *buf, unsigned lba, unsigned nblk)
 732 {
 733     static unsigned c = 0x2d5c7c2f;     /* twiddle */
 734
 735     c = (c << 8) | (c >> 24);
 736     xputc(c);
 737     xputc('\b');
 738     v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
 739     v86.addr = XREADORG;                /* call to xread in boot1 */
 740     v86.es = VTOPSEG(buf);
 741     v86.eax = lba;
 742     v86.ebx = VTOPOFF(buf);
 743     v86.ecx = lba >> 16;
 744     v86.edx = nblk << 8 | dsk.drive;
 745     v86int();
 746     v86.ctl = V86_FLAGS;
 747     if (V86_CY(v86.efl)) {
 748         printf("error %u lba %u\n", v86.eax >> 8 & 0xff, lba);
 749         return -1;
 750     }
 751     return 0;
 752 }
 753
 754 static int
 755 keyhit(unsigned ticks)
 756 {
 757     uint32_t t0, t1;
 758
 759     if (opts & 1 << RBX_NOINTR)
 760         return 0;
 761     t0 = 0;
 762     for (;;) {
 763         if (xgetc(1))
 764             return 1;
 765         t1 = *(uint32_t *)PTOV(0x46c);
 766         if (!t0)
 767             t0 = t1;
 768         if (t1 < t0 || t1 >= t0 + ticks)
 769             return 0;
 770     }
 771 }
 772
 773 static void
 774 xputc(int c)
 775 {
 776     if (opts & RBF_VIDEO)
 777         putc(c);
 778     if (opts & RBF_SERIAL)
 779         sio_putc(c);
 780 }
 781
 782 static int
 783 xgetc(int fn)
 784 {
 785     if (opts & 1 << RBX_NOINTR)
 786         return 0;
 787     for (;;) {
 788         if ((opts & RBF_VIDEO) && getc(1))
 789             return fn ? 1 : getc(0);
 790         if ((opts & RBF_SERIAL) && sio_ischar())
 791             return fn ? 1 : sio_getc();
 792         if (fn)
 793             return 0;
 794     }
 795 }
 796
 797 static int
 798 getc(int fn)
 799 {
 800     v86.addr = 0x16;
 801     v86.eax = fn << 8;
 802     v86int();
 803     return fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl);
 804 }