bios.c revision 111119 
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: head/sys/amd64/amd64/bios.c 111119 2003-02-19 05:47:46Z imp $
28 */
29
30/*
31 * Code for dealing with the BIOS in x86 PC systems.
32 */
33
34#include "opt_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 <sys/pcpu.h>
42#include <vm/vm.h>
43#include <vm/pmap.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#ifdef DEV_ISA
50#include <isa/isavar.h>
51#include <isa/pnpreg.h>
52#include <isa/pnpvar.h>
53#endif
54
55#define BIOS_START	0xe0000
56#define BIOS_SIZE	0x20000
57
58/* exported lookup results */
59struct bios32_SDentry		PCIbios;
60struct PnPBIOS_table		*PnPBIOStable;
61
62static u_int			bios32_SDCI;
63
64/* start fairly early */
65static void			bios32_init(void *junk);
66SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
67
68/*
69 * bios32_init
70 *
71 * Locate various bios32 entities.
72 */
73static void
74bios32_init(void *junk)
75{
76    u_long			sigaddr;
77    struct bios32_SDheader	*sdh;
78    struct PnPBIOS_table	*pt;
79    u_int8_t			ck, *cv;
80    int				i;
81    char			*p;
82
83    /*
84     * BIOS32 Service Directory, PCI BIOS
85     */
86
87    /* look for the signature */
88    if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
89
90	/* get a virtual pointer to the structure */
91	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
92	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
93	    ck += cv[i];
94	}
95	/* If checksum is OK, enable use of the entrypoint */
96	if ((ck == 0) && (BIOS_START <= sdh->entry ) &&
97	    (sdh->entry < (BIOS_START + BIOS_SIZE))) {
98	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
99	    if (bootverbose) {
100		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
101		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
102		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
103	    }
104
105	    /* Allow user override of PCI BIOS search */
106	    if (((p = getenv("machdep.bios.pci")) == NULL) || strcmp(p, "disable")) {
107
108		/* See if there's a PCI BIOS entrypoint here */
109		PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
110		if (!bios32_SDlookup(&PCIbios) && bootverbose)
111		    printf("pcibios: PCI BIOS entry at 0x%x+0x%x\n", PCIbios.base, PCIbios.entry);
112	    }
113	    if (p != NULL)
114		    freeenv(p);
115	} else {
116	    printf("bios32: Bad BIOS32 Service Directory\n");
117	}
118    }
119
120    /*
121     * PnP BIOS
122     *
123     * Allow user override of PnP BIOS search
124     */
125    if ((((p = getenv("machdep.bios.pnp")) == NULL) || strcmp(p, "disable")) &&
126	((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0)) {
127
128	/* get a virtual pointer to the structure */
129	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
130	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
131	    ck += cv[i];
132	}
133	/* If checksum is OK, enable use of the entrypoint */
134	if (ck == 0) {
135	    PnPBIOStable = pt;
136	    if (bootverbose) {
137		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
138		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
139		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
140		if ((pt->control & 0x3) == 0x01)
141		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
142		if (pt->oemdevid != 0)
143		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
144
145	    }
146	} else {
147	    printf("pnpbios: Bad PnP BIOS data checksum\n");
148	}
149    }
150    if (p != NULL)
151	    freeenv(p);
152    if (bootverbose) {
153	    /* look for other know signatures */
154	    printf("Other BIOS signatures found:\n");
155    }
156}
157
158/*
159 * bios32_SDlookup
160 *
161 * Query the BIOS32 Service Directory for the service named in (ent),
162 * returns nonzero if the lookup fails.  The caller must fill in
163 * (ent->ident), the remainder are populated on a successful lookup.
164 */
165int
166bios32_SDlookup(struct bios32_SDentry *ent)
167{
168    struct bios_regs args;
169
170    if (bios32_SDCI == 0)
171	return (1);
172
173    args.eax = ent->ident.id;		/* set up arguments */
174    args.ebx = args.ecx = args.edx = 0;
175    bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
176    if ((args.eax & 0xff) == 0) {	/* success? */
177	ent->base = args.ebx;
178	ent->len = args.ecx;
179	ent->entry = args.edx;
180	ent->ventry = BIOS_PADDRTOVADDR(ent->base + ent->entry);
181	return (0);			/* all OK */
182    }
183    return (1);				/* failed */
184}
185
186
187/*
188 * bios_sigsearch
189 *
190 * Search some or all of the BIOS region for a signature string.
191 *
192 * (start)	Optional offset returned from this function
193 *		(for searching for multiple matches), or NULL
194 *		to start the search from the base of the BIOS.
195 *		Note that this will be a _physical_ address in
196 *		the range 0xe0000 - 0xfffff.
197 * (sig)	is a pointer to the byte(s) of the signature.
198 * (siglen)	number of bytes in the signature.
199 * (paralen)	signature paragraph (alignment) size.
200 * (sigofs)	offset of the signature within the paragraph.
201 *
202 * Returns the _physical_ address of the found signature, 0 if the
203 * signature was not found.
204 */
205
206u_int32_t
207bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
208{
209    u_char	*sp, *end;
210
211    /* compute the starting address */
212    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
213	sp = (char *)BIOS_PADDRTOVADDR(start);
214    } else if (start == 0) {
215	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
216    } else {
217	return 0;				/* bogus start address */
218    }
219
220    /* compute the end address */
221    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
222
223    /* loop searching */
224    while ((sp + sigofs + siglen) < end) {
225
226	/* compare here */
227	if (!bcmp(sp + sigofs, sig, siglen)) {
228	    /* convert back to physical address */
229	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
230	}
231	sp += paralen;
232    }
233    return(0);
234}
235
236/*
237 * do not staticize, used by bioscall.s
238 */
239union {
240    struct {
241	u_short	offset;
242	u_short	segment;
243    } vec16;
244    struct {
245	u_int	offset;
246	u_short	segment;
247    } vec32;
248} bioscall_vector;			/* bios jump vector */
249
250void
251set_bios_selectors(struct bios_segments *seg, int flags)
252{
253    struct soft_segment_descriptor ssd = {
254	0,			/* segment base address (overwritten) */
255	0,			/* length (overwritten) */
256	SDT_MEMERA,		/* segment type (overwritten) */
257	0,			/* priority level */
258	1,			/* descriptor present */
259	0, 0,
260	1,			/* descriptor size (overwritten) */
261	0			/* granularity == byte units */
262    };
263    union descriptor *p_gdt;
264
265#ifdef SMP
266    p_gdt = &gdt[PCPU_GET(cpuid) * NGDT];
267#else
268    p_gdt = gdt;
269#endif
270
271    ssd.ssd_base = seg->code32.base;
272    ssd.ssd_limit = seg->code32.limit;
273    ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
274
275    ssd.ssd_def32 = 0;
276    if (flags & BIOSCODE_FLAG) {
277	ssd.ssd_base = seg->code16.base;
278	ssd.ssd_limit = seg->code16.limit;
279	ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
280    }
281
282    ssd.ssd_type = SDT_MEMRWA;
283    if (flags & BIOSDATA_FLAG) {
284	ssd.ssd_base = seg->data.base;
285	ssd.ssd_limit = seg->data.limit;
286	ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
287    }
288
289    if (flags & BIOSUTIL_FLAG) {
290	ssd.ssd_base = seg->util.base;
291	ssd.ssd_limit = seg->util.limit;
292	ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
293    }
294
295    if (flags & BIOSARGS_FLAG) {
296	ssd.ssd_base = seg->args.base;
297	ssd.ssd_limit = seg->args.limit;
298	ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
299    }
300}
301
302extern int vm86pa;
303extern void bios16_jmp(void);
304
305/*
306 * this routine is really greedy with selectors, and uses 5:
307 *
308 * 32-bit code selector:	to return to kernel
309 * 16-bit code selector:	for running code
310 *        data selector:	for 16-bit data
311 *        util selector:	extra utility selector
312 *        args selector:	to handle pointers
313 *
314 * the util selector is set from the util16 entry in bios16_args, if a
315 * "U" specifier is seen.
316 *
317 * See <machine/pc/bios.h> for description of format specifiers
318 */
319int
320bios16(struct bios_args *args, char *fmt, ...)
321{
322    char	*p, *stack, *stack_top;
323    va_list 	ap;
324    int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
325    u_int 	i, arg_start, arg_end;
326    pt_entry_t	*pte;
327    pd_entry_t	*ptd;
328
329    arg_start = 0xffffffff;
330    arg_end = 0;
331
332    /*
333     * Some BIOS entrypoints attempt to copy the largest-case
334     * argument frame (in order to generalise handling for
335     * different entry types).  If our argument frame is
336     * smaller than this, the BIOS will reach off the top of
337     * our constructed stack segment.  Pad the top of the stack
338     * with some garbage to avoid this.
339     */
340    stack = (caddr_t)PAGE_SIZE - 32;
341
342    va_start(ap, fmt);
343    for (p = fmt; p && *p; p++) {
344	switch (*p) {
345	case 'p':			/* 32-bit pointer */
346	    i = va_arg(ap, u_int);
347	    arg_start = min(arg_start, i);
348	    arg_end = max(arg_end, i);
349	    flags |= BIOSARGS_FLAG;
350	    stack -= 4;
351	    break;
352
353	case 'i':			/* 32-bit integer */
354	    i = va_arg(ap, u_int);
355	    stack -= 4;
356	    break;
357
358	case 'U':			/* 16-bit selector */
359	    flags |= BIOSUTIL_FLAG;
360	    /* FALLTHROUGH */
361	case 'D':			/* 16-bit selector */
362	case 'C':			/* 16-bit selector */
363	    stack -= 2;
364	    break;
365
366	case 's':			/* 16-bit integer passed as an int */
367	    i = va_arg(ap, int);
368	    stack -= 2;
369	    break;
370
371	default:
372	    return (EINVAL);
373	}
374    }
375
376    if (flags & BIOSARGS_FLAG) {
377	if (arg_end - arg_start > ctob(16))
378	    return (EACCES);
379	args->seg.args.base = arg_start;
380	args->seg.args.limit = 0xffff;
381    }
382
383    args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
384    args->seg.code32.limit = 0xffff;
385
386    ptd = (pd_entry_t *)rcr3();
387    if (ptd == (u_int *)IdlePTD) {
388	/*
389	 * no page table, so create one and install it.
390	 */
391	pte = (pt_entry_t *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
392	ptd = (pd_entry_t *)((u_int)ptd + KERNBASE);
393	*ptd = vtophys(pte) | PG_RW | PG_V;
394    } else {
395	/*
396	 * this is a user-level page table
397	 */
398	pte = PTmap;
399    }
400    /*
401     * install pointer to page 0.  we don't need to flush the tlb,
402     * since there should not be a previous mapping for page 0.
403     */
404    *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
405
406    stack_top = stack;
407    va_start(ap, fmt);
408    for (p = fmt; p && *p; p++) {
409	switch (*p) {
410	case 'p':			/* 32-bit pointer */
411	    i = va_arg(ap, u_int);
412	    *(u_int *)stack = (i - arg_start) |
413		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
414	    stack += 4;
415	    break;
416
417	case 'i':			/* 32-bit integer */
418	    i = va_arg(ap, u_int);
419	    *(u_int *)stack = i;
420	    stack += 4;
421	    break;
422
423	case 'U':			/* 16-bit selector */
424	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
425	    stack += 2;
426	    break;
427
428	case 'D':			/* 16-bit selector */
429	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
430	    stack += 2;
431	    break;
432
433	case 'C':			/* 16-bit selector */
434	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
435	    stack += 2;
436	    break;
437
438	case 's':			/* 16-bit integer passed as an int */
439	    i = va_arg(ap, int);
440	    *(u_short *)stack = i;
441	    stack += 2;
442	    break;
443
444	default:
445	    return (EINVAL);
446	}
447    }
448
449    set_bios_selectors(&args->seg, flags);
450    bioscall_vector.vec16.offset = (u_short)args->entry;
451    bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
452
453    i = bios16_call(&args->r, stack_top);
454
455    if (pte == PTmap) {
456	*pte = 0;			/* remove entry */
457    } else {
458	*ptd = 0;			/* remove page table */
459	free(pte, M_TEMP);		/* ... and free it */
460    }
461
462    /*
463     * XXX only needs to be invlpg(0) but that doesn't work on the 386
464     */
465    pmap_invalidate_all(kernel_pmap);
466
467    return (i);
468}
469
470#ifdef DEV_ISA
471/*
472 * PnP BIOS interface; enumerate devices only known to the system
473 * BIOS and save information about them for later use.
474 */
475
476struct pnp_sysdev
477{
478    u_int16_t	size;
479    u_int8_t	handle;
480    u_int32_t	devid;
481    u_int8_t	type[3];
482    u_int16_t	attrib;
483#define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
484#define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
485#define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
486#define PNPATTR_INPUT		(1<<3)	/* can be primary input */
487#define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
488#define PNPATTR_DOCK		(1<<5)	/* is a docking station */
489#define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
490#define PNPATTR_CONFIG_STATIC	(0)
491#define PNPATTR_CONFIG_DYNAMIC	(1)
492#define PNPATTR_CONFIG_DYNONLY	(3)
493#define PNPATTR_CONFIG(a)	(((a) >> 7) & 0x3)
494    /* device-specific data comes here */
495    u_int8_t	devdata[0];
496} __packed;
497
498/* We have to cluster arguments within a 64k range for the bios16 call */
499struct pnp_sysdevargs
500{
501    u_int16_t	next;
502    struct pnp_sysdev node;
503};
504
505/*
506 * This function is called after the bus has assigned resource
507 * locations for a logical device.
508 */
509static void
510pnpbios_set_config(void *arg, struct isa_config *config, int enable)
511{
512}
513
514/*
515 * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
516 */
517static void
518pnpbios_identify(driver_t *driver, device_t parent)
519{
520    struct PnPBIOS_table	*pt = PnPBIOStable;
521    struct bios_args		args;
522    struct pnp_sysdev		*pd;
523    struct pnp_sysdevargs	*pda;
524    u_int16_t			ndevs, bigdev;
525    int				error, currdev;
526    u_int8_t			*devnodebuf, tag;
527    u_int32_t			*devid, *compid;
528    int				idx, left;
529    device_t			dev;
530
531    /* no PnP BIOS information */
532    if (pt == NULL)
533	return;
534
535    /* ACPI already active */
536    if (devclass_get_softc(devclass_find("ACPI"), 0) != NULL)
537	return;
538
539    /* get count of PnP devices */
540    bzero(&args, sizeof(args));
541    args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
542    args.seg.code16.limit = 0xffff;		/* XXX ? */
543    args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
544    args.seg.data.limit = 0xffff;
545    args.entry = pt->pmentryoffset;
546
547    if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff))
548	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
549    ndevs &= 0xff;				/* clear high byte garbage */
550    if (bootverbose)
551	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
552
553    devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
554			M_DEVBUF, M_NOWAIT);
555    pda = (struct pnp_sysdevargs *)devnodebuf;
556    pd = &pda->node;
557
558    for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
559
560	bzero(pd, bigdev);
561	pda->next = currdev;
562	/* get current configuration */
563	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, 1))) {
564	    printf("pnpbios: error %d making BIOS16 call\n", error);
565	    break;
566	}
567	if ((error = (args.r.eax & 0xff))) {
568	    if (bootverbose)
569		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
570	    if (error & 0x80)
571		break;
572	}
573	currdev = pda->next;
574	if (pd->size < sizeof(struct pnp_sysdev)) {
575	    printf("pnpbios: bogus system node data, aborting scan\n");
576	    break;
577	}
578
579	/*
580	 * If we are in APIC_IO mode, we should ignore the ISA PIC if it
581	 * shows up.  Likewise, in !APIC_IO mode, we should ignore the
582	 * APIC (less important).
583	 * This is significant because the ISA PIC will claim IRQ 2 (which
584	 * it uses for chaining), while in APIC mode this is a valid IRQ
585	 * available for general use.
586	 */
587#ifdef APIC_IO
588	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0000"))	/* ISA PIC */
589	    continue;
590#else
591	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0003"))	/* APIC */
592	    continue;
593#endif
594
595	/* Add the device and parse its resources */
596	dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
597	isa_set_vendorid(dev, pd->devid);
598	isa_set_logicalid(dev, pd->devid);
599	/*
600	 * It appears that some PnP BIOS doesn't allow us to re-enable
601	 * the embedded system device once it is disabled.  We shall
602	 * mark all system device nodes as "cannot be disabled", regardless
603	 * of actual settings in the device attribute byte.
604	 * XXX
605	isa_set_configattr(dev,
606	    ((pd->attrib & PNPATTR_NODISABLE) ?  0 : ISACFGATTR_CANDISABLE) |
607	    ((!(pd->attrib & PNPATTR_NOCONFIG) &&
608		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
609		? ISACFGATTR_DYNAMIC : 0));
610	 */
611	isa_set_configattr(dev,
612	    (!(pd->attrib & PNPATTR_NOCONFIG) &&
613		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
614		? ISACFGATTR_DYNAMIC : 0);
615	ISA_SET_CONFIG_CALLBACK(parent, dev, pnpbios_set_config, 0);
616	pnp_parse_resources(dev, &pd->devdata[0],
617			    pd->size - sizeof(struct pnp_sysdev), 0);
618	if (!device_get_desc(dev))
619	    device_set_desc_copy(dev, pnp_eisaformat(pd->devid));
620
621	/* Find device IDs */
622	devid = &pd->devid;
623	compid = NULL;
624
625	/* look for a compatible device ID too */
626	left = pd->size - sizeof(struct pnp_sysdev);
627	idx = 0;
628	while (idx < left) {
629	    tag = pd->devdata[idx++];
630	    if (PNP_RES_TYPE(tag) == 0) {
631		/* Small resource */
632		switch (PNP_SRES_NUM(tag)) {
633		case PNP_TAG_COMPAT_DEVICE:
634		    compid = (u_int32_t *)(pd->devdata + idx);
635		    if (bootverbose)
636			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
637		    /* FALLTHROUGH */
638		case PNP_TAG_END:
639		    idx = left;
640		    break;
641		default:
642		    idx += PNP_SRES_LEN(tag);
643		    break;
644		}
645	    } else
646		/* Large resource, skip it */
647		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
648	}
649	if (bootverbose) {
650	    printf("pnpbios: handle %d device ID %s (%08x)",
651		   pd->handle, pnp_eisaformat(*devid), *devid);
652	    if (compid != NULL)
653		printf(" compat ID %s (%08x)",
654		       pnp_eisaformat(*compid), *compid);
655	    printf("\n");
656	}
657    }
658}
659
660static device_method_t pnpbios_methods[] = {
661	/* Device interface */
662	DEVMETHOD(device_identify,	pnpbios_identify),
663
664	{ 0, 0 }
665};
666
667static driver_t pnpbios_driver = {
668	"pnpbios",
669	pnpbios_methods,
670	1,			/* no softc */
671};
672
673static devclass_t pnpbios_devclass;
674
675DRIVER_MODULE(pnpbios, isa, pnpbios_driver, pnpbios_devclass, 0, 0);
676#endif /* DEV_ISA */
677