sys/platform/pc32/i386/bios.c

   1 /*-
   2  * Copyright (c) 1997 Michael Smith
   3  * Copyright (c) 1998 Jonathan Lemon
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * $FreeBSD: src/sys/i386/i386/bios.c,v 1.29.2.3 2001/07/19 18:07:35 imp Exp $
  28  * $DragonFly: src/sys/platform/pc32/i386/bios.c,v 1.16 2007/11/25 00:13:28 swildner Exp $
  29  */
  30
  31 /*
  32  * Code for dealing with the BIOS in x86 PC systems.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <vm/vm.h>
  39 #include <vm/pmap.h>
  40 #include <machine/md_var.h>
  41 #include <machine/vmparam.h>
  42 #include <machine/globaldata.h>
  43 #include <machine/pc/bios.h>
  44
  45 #define BIOS_START      0xe0000
  46 #define BIOS_SIZE       0x20000
  47
  48 /* exported lookup results */
  49 struct bios32_SDentry           PCIbios;
  50 struct PnPBIOS_table            *PnPBIOStable;
  51
  52 static u_int                    bios32_SDCI;
  53
  54 /* start fairly early */
  55 static void                     bios32_init(void *junk);
  56 SYSINIT(bios32, SI_BOOT2_BIOS, SI_ORDER_ANY, bios32_init, NULL);
  57
  58 /*
  59  * bios32_init
  60  *
  61  * Locate various bios32 entities.
  62  */
  63 static void
  64 bios32_init(void *junk)
  65 {
  66     u_long                      sigaddr;
  67     struct bios32_SDheader      *sdh;
  68     struct PnPBIOS_table        *pt;
  69     uint8_t                     ck, *cv;
  70     int                         i;
  71     char                        *p;
  72
  73     /*
  74      * BIOS32 Service Directory, PCI BIOS
  75      */
  76
  77     /* look for the signature */
  78     if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
  79
  80         /* get a virtual pointer to the structure */
  81         sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
  82         for (cv = (uint8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
  83             ck += cv[i];
  84         }
  85         /* If checksum is OK, enable use of the entrypoint */
  86         if ((ck == 0) && BIOS_START <= sdh->entry &&
  87             (sdh->entry < (BIOS_START + BIOS_SIZE))
  88         ) {
  89             bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
  90             if (bootverbose) {
  91                 kprintf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
  92                 kprintf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
  93                        sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
  94             }
  95
  96             /*  Allow user override of PCI BIOS search */
  97             if (((p = kgetenv("machdep.bios.pci")) == NULL) || strcmp(p, "disable")) {
  98                 /* See if there's a PCI BIOS entrypoint here */
  99                 PCIbios.ident.id = 0x49435024;  /* PCI systems should have this */
 100                 if (!bios32_SDlookup(&PCIbios) && bootverbose)
 101                     kprintf("pcibios: PCI BIOS entry at 0x%x\n", PCIbios.entry);
 102             }
 103             if (p != NULL)
 104                 kfreeenv(p);
 105         } else {
 106             kprintf("bios32: Bad BIOS32 Service Directory\n");
 107         }
 108     }
 109
 110     /*
 111      * PnP BIOS
 112      *
 113      * Allow user override of PnP BIOS search
 114      */
 115     if (((p = kgetenv("machdep.bios.pnp")) == NULL || strcmp(p, "disable")) &&
 116         (sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0
 117     ) {
 118         /* get a virtual pointer to the structure */
 119         pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
 120         for (cv = (uint8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
 121             ck += cv[i];
 122         }
 123         /* If checksum is OK, enable use of the entrypoint */
 124         if (ck == 0) {
 125             PnPBIOStable = pt;
 126             if (bootverbose) {
 127                 kprintf("pnpbios: Found PnP BIOS data at %p\n", pt);
 128                 kprintf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
 129                        pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
 130                 if ((pt->control & 0x3) == 0x01)
 131                     kprintf("pnpbios: Event flag at %x\n", pt->evflagaddr);
 132                 if (pt->oemdevid != 0)
 133                     kprintf("pnpbios: OEM ID %x\n", pt->oemdevid);
 134
 135             }
 136         } else {
 137             kprintf("pnpbios: Bad PnP BIOS data checksum\n");
 138         }
 139     }
 140     if (p != NULL)
 141         kfreeenv(p);
 142     if (bootverbose) {
 143             /* look for other know signatures */
 144             kprintf("Other BIOS signatures found:\n");
 145     }
 146 }
 147
 148 /*
 149  * bios32_SDlookup
 150  *
 151  * Query the BIOS32 Service Directory for the service named in (ent),
 152  * returns nonzero if the lookup fails.  The caller must fill in
 153  * (ent->ident), the remainder are populated on a successful lookup.
 154  */
 155 int
 156 bios32_SDlookup(struct bios32_SDentry *ent)
 157 {
 158     struct bios_regs args;
 159
 160     if (bios32_SDCI == 0)
 161         return (1);
 162
 163     args.eax = ent->ident.id;           /* set up arguments */
 164     args.ebx = args.ecx = args.edx = 0;
 165     bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
 166     if ((args.eax & 0xff) == 0) {       /* success? */
 167         ent->base = args.ebx;
 168         ent->len = args.ecx;
 169         ent->entry = args.edx;
 170         ent->ventry = BIOS_PADDRTOVADDR(ent->base + ent->entry);
 171         return (0);                     /* all OK */
 172     }
 173     return (1);                         /* failed */
 174 }
 175
 176
 177 /*
 178  * bios_sigsearch
 179  *
 180  * Search some or all of the BIOS region for a signature string.
 181  *
 182  * (start)      Optional offset returned from this function
 183  *              (for searching for multiple matches), or NULL
 184  *              to start the search from the base of the BIOS.
 185  *              Note that this will be a _physical_ address in
 186  *              the range 0xe0000 - 0xfffff.
 187  * (sig)        is a pointer to the byte(s) of the signature.
 188  * (siglen)     number of bytes in the signature.
 189  * (paralen)    signature paragraph (alignment) size.
 190  * (sigofs)     offset of the signature within the paragraph.
 191  *
 192  * Returns the _physical_ address of the found signature, 0 if the
 193  * signature was not found.
 194  */
 195
 196 uint32_t
 197 bios_sigsearch(uint32_t start, u_char *sig, int siglen, int paralen, int sigofs)
 198 {
 199     u_char      *sp, *end;
 200
 201     /* compute the starting address */
 202     if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
 203         sp = (char *)BIOS_PADDRTOVADDR(start);
 204     } else if (start == 0) {
 205         sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
 206     } else {
 207         return 0;                               /* bogus start address */
 208     }
 209
 210     /* compute the end address */
 211     end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
 212
 213     /* loop searching */
 214     while ((sp + sigofs + siglen) < end) {
 215
 216         /* compare here */
 217         if (!bcmp(sp + sigofs, sig, siglen)) {
 218             /* convert back to physical address */
 219             return((uint32_t)BIOS_VADDRTOPADDR(sp));
 220         }
 221         sp += paralen;
 222     }
 223     return(0);
 224 }
 225
 226 /*
 227  * do not staticize, used by bioscall.s
 228  */
 229 union {
 230     struct {
 231         uint16_t offset;
 232         uint16_t segment;
 233     } vec16;
 234     struct {
 235         uint32_t offset;
 236         uint16_t segment;
 237     } vec32;
 238 } bioscall_vector;                      /* bios jump vector */
 239
 240 void
 241 set_bios_selectors(struct bios_segments *seg, int flags)
 242 {
 243     struct soft_segment_descriptor ssd = {
 244         0,                      /* segment base address (overwritten) */
 245         0,                      /* length (overwritten) */
 246         SDT_MEMERA,             /* segment type (overwritten) */
 247         0,                      /* priority level */
 248         1,                      /* descriptor present */
 249         0, 0,
 250         1,                      /* descriptor size (overwritten) */
 251         0                       /* granularity == byte units */
 252     };
 253     union descriptor *p_gdt;
 254
 255     p_gdt = &gdt[mycpu->gd_cpuid * NGDT];
 256
 257     ssd.ssd_base = seg->code32.base;
 258     ssd.ssd_limit = seg->code32.limit;
 259     ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
 260
 261     ssd.ssd_def32 = 0;
 262     if (flags & BIOSCODE_FLAG) {
 263         ssd.ssd_base = seg->code16.base;
 264         ssd.ssd_limit = seg->code16.limit;
 265         ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
 266     }
 267
 268     ssd.ssd_type = SDT_MEMRWA;
 269     if (flags & BIOSDATA_FLAG) {
 270         ssd.ssd_base = seg->data.base;
 271         ssd.ssd_limit = seg->data.limit;
 272         ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
 273     }
 274
 275     if (flags & BIOSUTIL_FLAG) {
 276         ssd.ssd_base = seg->util.base;
 277         ssd.ssd_limit = seg->util.limit;
 278         ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
 279     }
 280
 281     if (flags & BIOSARGS_FLAG) {
 282         ssd.ssd_base = seg->args.base;
 283         ssd.ssd_limit = seg->args.limit;
 284         ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
 285     }
 286 }
 287
 288 extern int vm86pa;
 289 extern void bios16_jmp(void);
 290
 291 /*
 292  * this routine is really greedy with selectors, and uses 5:
 293  *
 294  * 32-bit code selector:        to return to kernel
 295  * 16-bit code selector:        for running code
 296  *        data selector:        for 16-bit data
 297  *        util selector:        extra utility selector
 298  *        args selector:        to handle pointers
 299  *
 300  * the util selector is set from the util16 entry in bios16_args, if a
 301  * "U" specifier is seen.
 302  *
 303  * See <machine/pc/bios.h> for description of format specifiers
 304  */
 305 int
 306 bios16(struct bios_args *args, char *fmt, ...)
 307 {
 308     char        *p, *stack, *stack_top;
 309     __va_list   ap;
 310     int         flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
 311     u_int       i, arg_start, arg_end;
 312     pt_entry_t  *pte;
 313     pd_entry_t  *ptd;
 314
 315     arg_start = 0xffffffff;
 316     arg_end = 0;
 317
 318     /*
 319      * Some BIOS entrypoints attempt to copy the largest-case
 320      * argument frame (in order to generalise handling for
 321      * different entry types).  If our argument frame is
 322      * smaller than this, the BIOS will reach off the top of
 323      * our constructed stack segment.  Pad the top of the stack
 324      * with some garbage to avoid this.
 325      */
 326     stack = (caddr_t)PAGE_SIZE - 32;
 327
 328     __va_start(ap, fmt);
 329     for (p = fmt; p && *p; p++) {
 330         switch (*p) {
 331         case 'p':                       /* 32-bit pointer */
 332             i = __va_arg(ap, u_int);
 333             arg_start = min(arg_start, i);
 334             arg_end = max(arg_end, i);
 335             flags |= BIOSARGS_FLAG;
 336             stack -= 4;
 337             break;
 338
 339         case 'i':                       /* 32-bit integer */
 340             i = __va_arg(ap, u_int);
 341             stack -= 4;
 342             break;
 343
 344         case 'U':                       /* 16-bit selector */
 345             flags |= BIOSUTIL_FLAG;
 346             /* FALLTHROUGH */
 347         case 'D':                       /* 16-bit selector */
 348         case 'C':                       /* 16-bit selector */
 349             stack -= 2;
 350             break;
 351
 352         case 's':                       /* 16-bit integer passed as an int */
 353             i = __va_arg(ap, int);
 354             stack -= 2;
 355             break;
 356
 357         default:
 358             return (EINVAL);
 359         }
 360     }
 361
 362     if (flags & BIOSARGS_FLAG) {
 363         if (arg_end - arg_start > ctob(16))
 364             return (EACCES);
 365         args->seg.args.base = arg_start;
 366         args->seg.args.limit = 0xffff;
 367     }
 368
 369     args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
 370     args->seg.code32.limit = 0xffff;
 371
 372     ptd = (pd_entry_t *)rcr3();
 373     if ((pd_entry_t)ptd == IdlePTD) {
 374         /*
 375          * no page table, so create one and install it.
 376          */
 377         pte = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK|M_ZERO);
 378         ptd = (pd_entry_t *)((vm_offset_t)ptd + KERNBASE);
 379         *ptd = vtophys(pte) | PG_RW | PG_V;
 380     } else {
 381         /*
 382          * this is a user-level page table
 383          */
 384         pte = PTmap;
 385     }
 386     /*
 387      * install pointer to page 0.  Flush the tlb for safety.  We don't
 388      * migrate between cpus so a local flush is sufficient.
 389      */
 390     *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
 391     cpu_invltlb();
 392
 393     stack_top = stack;
 394     __va_start(ap, fmt);
 395     for (p = fmt; p && *p; p++) {
 396         switch (*p) {
 397         case 'p':                       /* 32-bit pointer */
 398             i = __va_arg(ap, u_int);
 399             *(u_int *)stack = (i - arg_start) |
 400                 (GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
 401             stack += 4;
 402             break;
 403
 404         case 'i':                       /* 32-bit integer */
 405             i = __va_arg(ap, u_int);
 406             *(u_int *)stack = i;
 407             stack += 4;
 408             break;
 409
 410         case 'U':                       /* 16-bit selector */
 411             *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
 412             stack += 2;
 413             break;
 414
 415         case 'D':                       /* 16-bit selector */
 416             *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
 417             stack += 2;
 418             break;
 419
 420         case 'C':                       /* 16-bit selector */
 421             *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
 422             stack += 2;
 423             break;
 424
 425         case 's':                       /* 16-bit integer passed as an int */
 426             i = __va_arg(ap, int);
 427             *(u_short *)stack = i;
 428             stack += 2;
 429             break;
 430
 431         default:
 432             return (EINVAL);
 433         }
 434     }
 435
 436     set_bios_selectors(&args->seg, flags);
 437     bioscall_vector.vec16.offset = (u_short)args->entry;
 438     bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
 439
 440     i = bios16_call(&args->r, stack_top);
 441
 442     if (pte == PTmap) {
 443         *pte = 0;                       /* remove entry */
 444     } else {
 445         *ptd = 0;                       /* remove page table */
 446         kfree(pte, M_TEMP);             /* ... and free it */
 447     }
 448     /*
 449      * XXX only needs to be invlpg(0) but that doesn't work on the 386
 450      */
 451     cpu_invltlb();
 452     return (i);
 453 }
 454
 455 int
 456 bios_oem_strings(struct bios_oem *oem, u_char *buffer, size_t maxlen)
 457 {
 458         size_t idx = 0;
 459         struct bios_oem_signature *sig;
 460         u_int from, to;
 461         u_char c, *s, *se, *str, *bios_str;
 462         size_t i, off, len, tot;
 463
 464         if ( !oem || !buffer || maxlen<2 )
 465                 return(-1);
 466
 467         sig = oem->signature;
 468         if (!sig)
 469                 return(-2);
 470
 471         from = oem->range.from;
 472         to = oem->range.to;
 473         if ( (to<=from) || (from<BIOS_START) || (to>(BIOS_START+BIOS_SIZE)) )
 474                 return(-3);
 475
 476         while (sig->anchor != NULL) {
 477                 str = sig->anchor;
 478                 len = strlen(str);
 479                 off = sig->offset;
 480                 tot = sig->totlen;
 481                 /* make sure offset doesn't go beyond bios area */
 482                 if ( (to+off)>(BIOS_START+BIOS_SIZE) ||
 483                                         ((from+off)<BIOS_START) ) {
 484                         kprintf("sys/i386/i386/bios.c: sig '%s' "
 485                                 "from 0x%0x to 0x%0x offset %d "
 486                                 "out of BIOS bounds 0x%0x - 0x%0x\n",
 487                                 str, from, to, off,
 488                                 BIOS_START, BIOS_START+BIOS_SIZE);
 489                         return(-4);
 490                 }
 491                 /* make sure we don't overrun return buffer */
 492                 if (idx + tot > maxlen - 1) {
 493                         kprintf("sys/i386/i386/bios.c: sig '%s' "
 494                                 "idx %d + tot %d = %d > maxlen-1 %d\n",
 495                                 str, idx, tot, idx+tot, maxlen-1);
 496                         return(-5);
 497                 }
 498                 bios_str = NULL;
 499                 s = (u_char *)BIOS_PADDRTOVADDR(from);
 500                 se = (u_char *)BIOS_PADDRTOVADDR(to-len);
 501                 for (; s<se; s++) {
 502                         if (!bcmp(str, s, len)) {
 503                                 bios_str = s;
 504                                 break;
 505                         }
 506                 }
 507                 /*
 508                 *  store pretty version of totlen bytes of bios string with
 509                 *  given offset; 0x20 - 0x7E are printable; uniquify spaces
 510                 */
 511                 if (bios_str) {
 512                         for (i=0; i<tot; i++) {
 513                                 c = bios_str[i+off];
 514                                 if ( (c < 0x20) || (c > 0x7E) )
 515                                         c = ' ';
 516                                 if (idx == 0) {
 517                                         if (c != ' ')
 518                                                 buffer[idx++] = c;
 519                                 } else if ( (c != ' ') ||
 520                                         ((c == ' ') && (buffer[idx-1] != ' ')) )
 521                                                 buffer[idx++] = c;
 522                         }
 523                 }
 524                 sig++;
 525         }
 526         /* remove a final trailing space */
 527         if ( (idx > 1) && (buffer[idx-1] == ' ') )
 528                 idx--;
 529         buffer[idx] = '\0';
 530         return (idx);
 531 }