xref: /freebsd/sys/i386/i386/bios.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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  * $FreeBSD$
28  */
29 
30 /*
31  * Code for dealing with the BIOS in x86 PC systems.
32  */
33 
34 #include "isa.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/bus.h>
41 #include <vm/vm.h>
42 #include <vm/pmap.h>
43 #include <machine/globals.h>
44 #include <machine/md_var.h>
45 #include <machine/segments.h>
46 #include <machine/stdarg.h>
47 #include <machine/vmparam.h>
48 #include <machine/pc/bios.h>
49 #include <isa/isavar.h>
50 #include <isa/pnpreg.h>
51 #include <isa/pnpvar.h>
52 
53 #define BIOS_START	0xe0000
54 #define BIOS_SIZE	0x20000
55 
56 /* exported lookup results */
57 struct bios32_SDentry		PCIbios = {entry : 0};
58 struct PnPBIOS_table		*PnPBIOStable = 0;
59 
60 static u_int			bios32_SDCI = 0;
61 
62 /* start fairly early */
63 static void			bios32_init(void *junk);
64 SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
65 
66 /*
67  * bios32_init
68  *
69  * Locate various bios32 entities.
70  */
71 static void
72 bios32_init(void *junk)
73 {
74     u_long			sigaddr;
75     struct bios32_SDheader	*sdh;
76     struct PnPBIOS_table	*pt;
77     u_int8_t			ck, *cv;
78     int				i;
79     char			*p;
80 
81     /*
82      * BIOS32 Service Directory, PCI BIOS
83      */
84 
85     /* look for the signature */
86     if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
87 
88 	/* get a virtual pointer to the structure */
89 	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
90 	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
91 	    ck += cv[i];
92 	}
93 	/* If checksum is OK, enable use of the entrypoint */
94 	if ((ck == 0) && (sdh->entry < (BIOS_START + BIOS_SIZE))) {
95 	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
96 	    if (bootverbose) {
97 		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
98 		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
99 		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
100 	    }
101 
102 #ifndef PC98
103 	    /* Allow user override of PCI BIOS search */
104 	    if (((p = getenv("machdep.bios.pci")) == NULL) || strcmp(p, "disable")) {
105 
106 		/* See if there's a PCI BIOS entrypoint here */
107 		PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
108 		if (!bios32_SDlookup(&PCIbios) && bootverbose)
109 		    printf("pcibios: PCI BIOS entry at 0x%x+0x%x\n", PCIbios.base, PCIbios.entry);
110 	    }
111 #endif
112 	} else {
113 	    printf("bios32: Bad BIOS32 Service Directory\n");
114 	}
115     }
116 
117     /*
118      * PnP BIOS
119      *
120      * Allow user override of PnP BIOS search
121      */
122     if ((((p = getenv("machdep.bios.pnp")) == NULL) || strcmp(p, "disable")) &&
123 	((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0)) {
124 
125 	/* get a virtual pointer to the structure */
126 	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
127 	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
128 	    ck += cv[i];
129 	}
130 	/* If checksum is OK, enable use of the entrypoint */
131 	if (ck == 0) {
132 	    PnPBIOStable = pt;
133 	    if (bootverbose) {
134 		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
135 		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
136 		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
137 		if ((pt->control & 0x3) == 0x01)
138 		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
139 		if (pt->oemdevid != 0)
140 		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
141 
142 	    }
143 	} else {
144 	    printf("pnpbios: Bad PnP BIOS data checksum\n");
145 	}
146     }
147     if (bootverbose) {
148 	    /* look for other know signatures */
149 	    printf("Other BIOS signatures found:\n");
150     }
151 }
152 
153 /*
154  * bios32_SDlookup
155  *
156  * Query the BIOS32 Service Directory for the service named in (ent),
157  * returns nonzero if the lookup fails.  The caller must fill in
158  * (ent->ident), the remainder are populated on a successful lookup.
159  */
160 int
161 bios32_SDlookup(struct bios32_SDentry *ent)
162 {
163     struct bios_regs args;
164 
165     if (bios32_SDCI == 0)
166 	return (1);
167 
168     args.eax = ent->ident.id;		/* set up arguments */
169     args.ebx = args.ecx = args.edx = 0;
170     bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
171     if ((args.eax & 0xff) == 0) {	/* success? */
172 	ent->base = args.ebx;
173 	ent->len = args.ecx;
174 	ent->entry = args.edx;
175 	ent->ventry = BIOS_PADDRTOVADDR(ent->base + ent->entry);
176 	return (0);			/* all OK */
177     }
178     return (1);				/* failed */
179 }
180 
181 
182 /*
183  * bios_sigsearch
184  *
185  * Search some or all of the BIOS region for a signature string.
186  *
187  * (start)	Optional offset returned from this function
188  *		(for searching for multiple matches), or NULL
189  *		to start the search from the base of the BIOS.
190  *		Note that this will be a _physical_ address in
191  *		the range 0xe0000 - 0xfffff.
192  * (sig)	is a pointer to the byte(s) of the signature.
193  * (siglen)	number of bytes in the signature.
194  * (paralen)	signature paragraph (alignment) size.
195  * (sigofs)	offset of the signature within the paragraph.
196  *
197  * Returns the _physical_ address of the found signature, 0 if the
198  * signature was not found.
199  */
200 
201 u_int32_t
202 bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
203 {
204     u_char	*sp, *end;
205 
206     /* compute the starting address */
207     if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
208 	sp = (char *)BIOS_PADDRTOVADDR(start);
209     } else if (start == 0) {
210 	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
211     } else {
212 	return 0;				/* bogus start address */
213     }
214 
215     /* compute the end address */
216     end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
217 
218     /* loop searching */
219     while ((sp + sigofs + siglen) < end) {
220 
221 	/* compare here */
222 	if (!bcmp(sp + sigofs, sig, siglen)) {
223 	    /* convert back to physical address */
224 	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
225 	}
226 	sp += paralen;
227     }
228     return(0);
229 }
230 
231 /*
232  * do not staticize, used by bioscall.s
233  */
234 union {
235     struct {
236 	u_short	offset;
237 	u_short	segment;
238     } vec16;
239     struct {
240 	u_int	offset;
241 	u_short	segment;
242     } vec32;
243 } bioscall_vector;			/* bios jump vector */
244 
245 void
246 set_bios_selectors(struct bios_segments *seg, int flags)
247 {
248     struct soft_segment_descriptor ssd = {
249 	0,			/* segment base address (overwritten) */
250 	0,			/* length (overwritten) */
251 	SDT_MEMERA,		/* segment type (overwritten) */
252 	0,			/* priority level */
253 	1,			/* descriptor present */
254 	0, 0,
255 	1,			/* descriptor size (overwritten) */
256 	0			/* granularity == byte units */
257     };
258     union descriptor *p_gdt;
259 
260 #ifdef SMP
261     p_gdt = &gdt[cpuid * NGDT];
262 #else
263     p_gdt = gdt;
264 #endif
265 
266     ssd.ssd_base = seg->code32.base;
267     ssd.ssd_limit = seg->code32.limit;
268     ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
269 
270     ssd.ssd_def32 = 0;
271     if (flags & BIOSCODE_FLAG) {
272 	ssd.ssd_base = seg->code16.base;
273 	ssd.ssd_limit = seg->code16.limit;
274 	ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
275     }
276 
277     ssd.ssd_type = SDT_MEMRWA;
278     if (flags & BIOSDATA_FLAG) {
279 	ssd.ssd_base = seg->data.base;
280 	ssd.ssd_limit = seg->data.limit;
281 	ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
282     }
283 
284     if (flags & BIOSUTIL_FLAG) {
285 	ssd.ssd_base = seg->util.base;
286 	ssd.ssd_limit = seg->util.limit;
287 	ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
288     }
289 
290     if (flags & BIOSARGS_FLAG) {
291 	ssd.ssd_base = seg->args.base;
292 	ssd.ssd_limit = seg->args.limit;
293 	ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
294     }
295 }
296 
297 extern int vm86pa;
298 extern void bios16_jmp(void);
299 
300 /*
301  * this routine is really greedy with selectors, and uses 5:
302  *
303  * 32-bit code selector:	to return to kernel
304  * 16-bit code selector:	for running code
305  *        data selector:	for 16-bit data
306  *        util selector:	extra utility selector
307  *        args selector:	to handle pointers
308  *
309  * the util selector is set from the util16 entry in bios16_args, if a
310  * "U" specifier is seen.
311  *
312  * See <machine/pc/bios.h> for description of format specifiers
313  */
314 int
315 bios16(struct bios_args *args, char *fmt, ...)
316 {
317     char	*p, *stack, *stack_top;
318     va_list 	ap;
319     int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
320     u_int 	i, arg_start, arg_end;
321     u_int 	*pte, *ptd;
322 
323     arg_start = 0xffffffff;
324     arg_end = 0;
325 
326     /*
327      * Some BIOS entrypoints attempt to copy the largest-case
328      * argument frame (in order to generalise handling for
329      * different entry types).  If our argument frame is
330      * smaller than this, the BIOS will reach off the top of
331      * our constructed stack segment.  Pad the top of the stack
332      * with some garbage to avoid this.
333      */
334     stack = (caddr_t)PAGE_SIZE - 32;
335 
336     va_start(ap, fmt);
337     for (p = fmt; p && *p; p++) {
338 	switch (*p) {
339 	case 'p':			/* 32-bit pointer */
340 	    i = va_arg(ap, u_int);
341 	    arg_start = min(arg_start, i);
342 	    arg_end = max(arg_end, i);
343 	    flags |= BIOSARGS_FLAG;
344 	    stack -= 4;
345 	    break;
346 
347 	case 'i':			/* 32-bit integer */
348 	    i = va_arg(ap, u_int);
349 	    stack -= 4;
350 	    break;
351 
352 	case 'U':			/* 16-bit selector */
353 	    flags |= BIOSUTIL_FLAG;
354 	    /* FALLTHROUGH */
355 	case 'D':			/* 16-bit selector */
356 	case 'C':			/* 16-bit selector */
357 	    stack -= 2;
358 	    break;
359 
360 	case 's':			/* 16-bit integer */
361 	    i = va_arg(ap, u_short);
362 	    stack -= 2;
363 	    break;
364 
365 	default:
366 	    return (EINVAL);
367 	}
368     }
369 
370     if (flags & BIOSARGS_FLAG) {
371 	if (arg_end - arg_start > ctob(16))
372 	    return (EACCES);
373 	args->seg.args.base = arg_start;
374 	args->seg.args.limit = 0xffff;
375     }
376 
377     args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
378     args->seg.code32.limit = 0xffff;
379 
380     ptd = (u_int *)rcr3();
381     if (ptd == IdlePTD) {
382 	/*
383 	 * no page table, so create one and install it.
384 	 */
385 	pte = (u_int *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
386 	ptd = (u_int *)((u_int)ptd + KERNBASE);
387 	*ptd = vtophys(pte) | PG_RW | PG_V;
388     } else {
389 	/*
390 	 * this is a user-level page table
391 	 */
392 	pte = (u_int *)&PTmap;
393     }
394     /*
395      * install pointer to page 0.  we don't need to flush the tlb,
396      * since there should not be a previous mapping for page 0.
397      */
398     *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
399 
400     stack_top = stack;
401     va_start(ap, fmt);
402     for (p = fmt; p && *p; p++) {
403 	switch (*p) {
404 	case 'p':			/* 32-bit pointer */
405 	    i = va_arg(ap, u_int);
406 	    *(u_int *)stack = (i - arg_start) |
407 		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
408 	    stack += 4;
409 	    break;
410 
411 	case 'i':			/* 32-bit integer */
412 	    i = va_arg(ap, u_int);
413 	    *(u_int *)stack = i;
414 	    stack += 4;
415 	    break;
416 
417 	case 'U':			/* 16-bit selector */
418 	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
419 	    stack += 2;
420 	    break;
421 
422 	case 'D':			/* 16-bit selector */
423 	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
424 	    stack += 2;
425 	    break;
426 
427 	case 'C':			/* 16-bit selector */
428 	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
429 	    stack += 2;
430 	    break;
431 
432 	case 's':			/* 16-bit integer */
433 	    i = va_arg(ap, u_short);
434 	    *(u_short *)stack = i;
435 	    stack += 2;
436 	    break;
437 
438 	default:
439 	    return (EINVAL);
440 	}
441     }
442 
443     set_bios_selectors(&args->seg, flags);
444     bioscall_vector.vec16.offset = (u_short)args->entry;
445     bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
446 
447     i = bios16_call(&args->r, stack_top);
448 
449     if (pte == (u_int *)&PTmap) {
450 	*pte = 0;			/* remove entry */
451     } else {
452 	*ptd = 0;			/* remove page table */
453 	free(pte, M_TEMP);		/* ... and free it */
454     }
455 
456     /*
457      * XXX only needs to be invlpg(0) but that doesn't work on the 386
458      */
459     invltlb();
460 
461     return (i);
462 }
463 
464 /*
465  * PnP BIOS interface; enumerate devices only known to the system
466  * BIOS and save information about them for later use.
467  */
468 
469 struct pnp_sysdev
470 {
471     u_int16_t	size;
472     u_int8_t	handle;
473     u_int32_t	devid;
474     u_int8_t	type[3];
475     u_int16_t	attrib;
476 #define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
477 #define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
478 #define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
479 #define PNPATTR_INPUT		(1<<3)	/* can be primary input */
480 #define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
481 #define PNPATTR_DOCK		(1<<5)	/* is a docking station */
482 #define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
483 #define PNPATTR_CONFIG_STATIC	0x00
484 #define PNPATTR_CONFIG_DYNAMIC	0x07
485 #define PNPATTR_CONFIG_DYNONLY	0x17
486     /* device-specific data comes here */
487     u_int8_t	devdata[0];
488 } __attribute__ ((packed));
489 
490 /* We have to cluster arguments within a 64k range for the bios16 call */
491 struct pnp_sysdevargs
492 {
493     u_int16_t	next;
494     struct pnp_sysdev node;
495 };
496 
497 /*
498  * This function is called after the bus has assigned resource
499  * locations for a logical device.
500  */
501 static void
502 pnpbios_set_config(void *arg, struct isa_config *config, int enable)
503 {
504 }
505 
506 /*
507  * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
508  */
509 static void
510 pnpbios_identify(driver_t *driver, device_t parent)
511 {
512     struct PnPBIOS_table	*pt = PnPBIOStable;
513     struct bios_args		args;
514     struct pnp_sysdev		*pd;
515     struct pnp_sysdevargs	*pda;
516     u_int16_t			ndevs, bigdev;
517     int				error, currdev;
518     u_int8_t			*devnodebuf, tag;
519     u_int32_t			*devid, *compid;
520     int				idx, left;
521     device_t			dev;
522 
523     /* no PnP BIOS information */
524     if (pt == NULL)
525 	return;
526 
527     bzero(&args, sizeof(args));
528     args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
529     args.seg.code16.limit = 0xffff;		/* XXX ? */
530     args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
531     args.seg.data.limit = 0xffff;
532     args.entry = pt->pmentryoffset;
533 
534     if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff))
535 	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
536     ndevs &= 0xff;				/* clear high byte garbage */
537     if (bootverbose)
538 	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
539 
540     devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
541 			M_DEVBUF, M_NOWAIT);
542     pda = (struct pnp_sysdevargs *)devnodebuf;
543     pd = &pda->node;
544 
545     for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
546 
547 	bzero(pd, bigdev);
548 	pda->next = currdev;
549 	/* get current configuration */
550 	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, (u_int16_t)1))) {
551 	    printf("pnpbios: error %d making BIOS16 call\n", error);
552 	    break;
553 	}
554 	if ((error = (args.r.eax & 0xff))) {
555 	    if (bootverbose)
556 		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
557 	    if (error & 0x80)
558 		break;
559 	}
560 	currdev = pda->next;
561 	if (pd->size < sizeof(struct pnp_sysdev)) {
562 	    printf("pnpbios: bogus system node data, aborting scan\n");
563 	    break;
564 	}
565 
566 	/*
567 	 * If we are in APIC_IO mode, we should ignore the ISA PIC if it
568 	 * shows up.  Likewise, in !APIC_IO mode, we should ignore the
569 	 * APIC (less important).
570 	 * This is significant because the ISA PIC will claim IRQ 2 (which
571 	 * it uses for chaining), while in APIC mode this is a valid IRQ
572 	 * available for general use.
573 	 */
574 #ifdef APIC_IO
575 	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0000"))	/* ISA PIC */
576 	    continue;
577 #else
578 	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0003"))	/* APIC */
579 	    continue;
580 #endif
581 
582 	/* Add the device and parse its resources */
583 	dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
584 	isa_set_vendorid(dev, pd->devid);
585 	isa_set_logicalid(dev, pd->devid);
586 	ISA_SET_CONFIG_CALLBACK(parent, dev, pnpbios_set_config, 0);
587 	pnp_parse_resources(dev, &pd->devdata[0],
588 			    pd->size - sizeof(struct pnp_sysdev),
589 			    isa_get_vendorid(dev), isa_get_logicalid(dev), 0);
590 	if (!device_get_desc(dev))
591 	    device_set_desc_copy(dev, pnp_eisaformat(pd->devid));
592 
593 	/* Find device IDs */
594 	devid = &pd->devid;
595 	compid = NULL;
596 
597 	/* look for a compatible device ID too */
598 	left = pd->size - sizeof(struct pnp_sysdev);
599 	idx = 0;
600 	while (idx < left) {
601 	    tag = pd->devdata[idx++];
602 	    if (PNP_RES_TYPE(tag) == 0) {
603 		/* Small resource */
604 		switch (PNP_SRES_NUM(tag)) {
605 		case PNP_TAG_COMPAT_DEVICE:
606 		    compid = (u_int32_t *)(pd->devdata + idx);
607 		    if (bootverbose)
608 			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
609 		    /* FALLTHROUGH */
610 		case PNP_TAG_END:
611 		    idx = left;
612 		    break;
613 		default:
614 		    idx += PNP_SRES_LEN(tag);
615 		    break;
616 		}
617 	    } else
618 		/* Large resource, skip it */
619 		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
620 	}
621 	if (bootverbose) {
622 	    printf("pnpbios: handle %d device ID %s (%08x)",
623 		   pd->handle, pnp_eisaformat(*devid), *devid);
624 	    if (compid != NULL)
625 		printf(" compat ID %s (%08x)",
626 		       pnp_eisaformat(*compid), *compid);
627 	    printf("\n");
628 	}
629     }
630 }
631 
632 static device_method_t pnpbios_methods[] = {
633 	/* Device interface */
634 	DEVMETHOD(device_identify,	pnpbios_identify),
635 
636 	{ 0, 0 }
637 };
638 
639 static driver_t pnpbios_driver = {
640 	"pnpbios",
641 	pnpbios_methods,
642 	1,			/* no softc */
643 };
644 
645 static devclass_t pnpbios_devclass;
646 
647 DRIVER_MODULE(pnpbios, isa, pnpbios_driver, pnpbios_devclass, 0, 0);
648