xref: /freebsd/sys/i386/i386/bios.c (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1997 Michael Smith
5  * Copyright (c) 1998 Jonathan Lemon
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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 the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 /*
32  * Code for dealing with the BIOS in x86 PC systems.
33  */
34 
35 #include "opt_isa.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/bus.h>
43 #include <sys/pcpu.h>
44 #include <vm/vm.h>
45 #include <vm/pmap.h>
46 #include <machine/md_var.h>
47 #include <machine/segments.h>
48 #include <machine/stdarg.h>
49 #include <machine/vmparam.h>
50 #include <machine/pc/bios.h>
51 #ifdef DEV_ISA
52 #include <isa/isavar.h>
53 #include <isa/pnpreg.h>
54 #include <isa/pnpvar.h>
55 #endif
56 
57 #define BIOS_START	0xe0000
58 #define BIOS_SIZE	0x20000
59 
60 /* exported lookup results */
61 struct bios32_SDentry		PCIbios;
62 
63 static struct PnPBIOS_table	*PnPBIOStable;
64 
65 static u_int			bios32_SDCI;
66 
67 /* start fairly early */
68 static void			bios32_init(void *junk);
69 SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
70 
71 /*
72  * bios32_init
73  *
74  * Locate various bios32 entities.
75  */
76 static void
77 bios32_init(void *junk)
78 {
79     u_long			sigaddr;
80     struct bios32_SDheader	*sdh;
81     struct PnPBIOS_table	*pt;
82     u_int8_t			ck, *cv;
83     int				i;
84     char			*p;
85 
86     /*
87      * BIOS32 Service Directory, PCI BIOS
88      */
89 
90     /* look for the signature */
91     if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
92 	/* get a virtual pointer to the structure */
93 	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
94 	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
95 	    ck += cv[i];
96 	}
97 	/* If checksum is OK, enable use of the entrypoint */
98 	if ((ck == 0) && (BIOS_START <= sdh->entry ) &&
99 	    (sdh->entry < (BIOS_START + BIOS_SIZE))) {
100 	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
101 	    if (bootverbose) {
102 		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
103 		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
104 		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
105 	    }
106 
107 	    /* Allow user override of PCI BIOS search */
108 	    if (((p = kern_getenv("machdep.bios.pci")) == NULL) || strcmp(p, "disable")) {
109 		/* See if there's a PCI BIOS entrypoint here */
110 		PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
111 		if (!bios32_SDlookup(&PCIbios) && bootverbose)
112 		    printf("pcibios: PCI BIOS entry at 0x%x+0x%x\n", PCIbios.base, PCIbios.entry);
113 	    }
114 	    if (p != NULL)
115 		    freeenv(p);
116 	} else {
117 	    printf("bios32: Bad BIOS32 Service Directory\n");
118 	}
119     }
120 
121     /*
122      * PnP BIOS
123      *
124      * Allow user override of PnP BIOS search
125      */
126     if ((((p = kern_getenv("machdep.bios.pnp")) == NULL) || strcmp(p, "disable")) &&
127 	((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0)) {
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  */
165 int
166 bios32_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  * bios_sigsearch
188  *
189  * Search some or all of the BIOS region for a signature string.
190  *
191  * (start)	Optional offset returned from this function
192  *		(for searching for multiple matches), or NULL
193  *		to start the search from the base of the BIOS.
194  *		Note that this will be a _physical_ address in
195  *		the range 0xe0000 - 0xfffff.
196  * (sig)	is a pointer to the byte(s) of the signature.
197  * (siglen)	number of bytes in the signature.
198  * (paralen)	signature paragraph (alignment) size.
199  * (sigofs)	offset of the signature within the paragraph.
200  *
201  * Returns the _physical_ address of the found signature, 0 if the
202  * signature was not found.
203  */
204 
205 u_int32_t
206 bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
207 {
208     u_char	*sp, *end;
209 
210     /* compute the starting address */
211     if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
212 	sp = (char *)BIOS_PADDRTOVADDR(start);
213     } else if (start == 0) {
214 	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
215     } else {
216 	return 0;				/* bogus start address */
217     }
218 
219     /* compute the end address */
220     end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
221 
222     /* loop searching */
223     while ((sp + sigofs + siglen) < end) {
224 	/* compare here */
225 	if (!bcmp(sp + sigofs, sig, siglen)) {
226 	    /* convert back to physical address */
227 	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
228 	}
229 	sp += paralen;
230     }
231     return(0);
232 }
233 
234 /*
235  * do not staticize, used by bioscall.s
236  */
237 union {
238     struct {
239 	u_short	offset;
240 	u_short	segment;
241     } vec16;
242     struct {
243 	u_int	offset;
244 	u_short	segment;
245     } vec32;
246 } bioscall_vector;			/* bios jump vector */
247 
248 void
249 set_bios_selectors(struct bios_segments *seg, int flags)
250 {
251     struct soft_segment_descriptor ssd = {
252 	0,			/* segment base address (overwritten) */
253 	0,			/* length (overwritten) */
254 	SDT_MEMERA,		/* segment type (overwritten) */
255 	0,			/* priority level */
256 	1,			/* descriptor present */
257 	0, 0,
258 	1,			/* descriptor size (overwritten) */
259 	0			/* granularity == byte units */
260     };
261     union descriptor *p_gdt;
262 
263 #ifdef SMP
264     p_gdt = &gdt[PCPU_GET(cpuid) * NGDT];
265 #else
266     p_gdt = gdt;
267 #endif
268 
269     ssd.ssd_base = seg->code32.base;
270     ssd.ssd_limit = seg->code32.limit;
271     ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
272 
273     ssd.ssd_def32 = 0;
274     if (flags & BIOSCODE_FLAG) {
275 	ssd.ssd_base = seg->code16.base;
276 	ssd.ssd_limit = seg->code16.limit;
277 	ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
278     }
279 
280     ssd.ssd_type = SDT_MEMRWA;
281     if (flags & BIOSDATA_FLAG) {
282 	ssd.ssd_base = seg->data.base;
283 	ssd.ssd_limit = seg->data.limit;
284 	ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
285     }
286 
287     if (flags & BIOSUTIL_FLAG) {
288 	ssd.ssd_base = seg->util.base;
289 	ssd.ssd_limit = seg->util.limit;
290 	ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
291     }
292 
293     if (flags & BIOSARGS_FLAG) {
294 	ssd.ssd_base = seg->args.base;
295 	ssd.ssd_limit = seg->args.limit;
296 	ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
297     }
298 }
299 
300 extern int vm86pa;
301 extern u_long vm86phystk;
302 extern void bios16_jmp(void);
303 
304 /*
305  * this routine is really greedy with selectors, and uses 5:
306  *
307  * 32-bit code selector:	to return to kernel
308  * 16-bit code selector:	for running code
309  *        data selector:	for 16-bit data
310  *        util selector:	extra utility selector
311  *        args selector:	to handle pointers
312  *
313  * the util selector is set from the util16 entry in bios16_args, if a
314  * "U" specifier is seen.
315  *
316  * See <machine/pc/bios.h> for description of format specifiers
317  */
318 int
319 bios16(struct bios_args *args, char *fmt, ...)
320 {
321     char	*p, *stack, *stack_top;
322     va_list 	ap;
323     int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
324     u_int 	i, arg_start, arg_end;
325     void	*bios16_pmap_handle;
326     arg_start = 0xffffffff;
327     arg_end = 0;
328 
329     /*
330      * Some BIOS entrypoints attempt to copy the largest-case
331      * argument frame (in order to generalise handling for
332      * different entry types).  If our argument frame is
333      * smaller than this, the BIOS will reach off the top of
334      * our constructed stack segment.  Pad the top of the stack
335      * with some garbage to avoid this.
336      */
337     stack = (caddr_t)PAGE_SIZE - 32;
338 
339     va_start(ap, fmt);
340     for (p = fmt; p && *p; p++) {
341 	switch (*p) {
342 	case 'p':			/* 32-bit pointer */
343 	    i = va_arg(ap, u_int);
344 	    arg_start = min(arg_start, i);
345 	    arg_end = max(arg_end, i);
346 	    flags |= BIOSARGS_FLAG;
347 	    stack -= 4;
348 	    break;
349 
350 	case 'i':			/* 32-bit integer */
351 	    i = va_arg(ap, u_int);
352 	    stack -= 4;
353 	    break;
354 
355 	case 'U':			/* 16-bit selector */
356 	    flags |= BIOSUTIL_FLAG;
357 	    /* FALLTHROUGH */
358 	case 'D':			/* 16-bit selector */
359 	case 'C':			/* 16-bit selector */
360 	    stack -= 2;
361 	    break;
362 
363 	case 's':			/* 16-bit integer passed as an int */
364 	    i = va_arg(ap, int);
365 	    stack -= 2;
366 	    break;
367 
368 	default:
369 	    va_end(ap);
370 	    return (EINVAL);
371 	}
372     }
373     va_end(ap);
374 
375     if (flags & BIOSARGS_FLAG) {
376 	if (arg_end - arg_start > ctob(16))
377 	    return (EACCES);
378 	args->seg.args.base = arg_start;
379 	args->seg.args.limit = 0xffff;
380     }
381 
382     args->seg.code32.base = pmap_pg_frame((u_int)&bios16_jmp);
383     args->seg.code32.limit = 0xffff;
384 
385     bios16_pmap_handle = pmap_bios16_enter();
386 
387     stack_top = stack;
388     va_start(ap, fmt);
389     for (p = fmt; p && *p; p++) {
390 	switch (*p) {
391 	case 'p':			/* 32-bit pointer */
392 	    i = va_arg(ap, u_int);
393 	    *(u_int *)stack = (i - arg_start) |
394 		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
395 	    stack += 4;
396 	    break;
397 
398 	case 'i':			/* 32-bit integer */
399 	    i = va_arg(ap, u_int);
400 	    *(u_int *)stack = i;
401 	    stack += 4;
402 	    break;
403 
404 	case 'U':			/* 16-bit selector */
405 	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
406 	    stack += 2;
407 	    break;
408 
409 	case 'D':			/* 16-bit selector */
410 	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
411 	    stack += 2;
412 	    break;
413 
414 	case 'C':			/* 16-bit selector */
415 	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
416 	    stack += 2;
417 	    break;
418 
419 	case 's':			/* 16-bit integer passed as an int */
420 	    i = va_arg(ap, int);
421 	    *(u_short *)stack = i;
422 	    stack += 2;
423 	    break;
424 
425 	default:
426 	    va_end(ap);
427 	    return (EINVAL);
428 	}
429     }
430     va_end(ap);
431 
432     set_bios_selectors(&args->seg, flags);
433     bioscall_vector.vec16.offset = (u_short)args->entry;
434     bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
435 
436     i = bios16_call(&args->r, stack_top);
437     pmap_bios16_leave(bios16_pmap_handle);
438     return (i);
439 }
440 
441 int
442 bios_oem_strings(struct bios_oem *oem, u_char *buffer, size_t maxlen)
443 {
444 	size_t idx = 0;
445 	struct bios_oem_signature *sig;
446 	u_int from, to;
447 	u_char c, *s, *se, *str, *bios_str;
448 	size_t i, off, len, tot;
449 
450 	if ( !oem || !buffer || maxlen<2 )
451 		return(-1);
452 
453 	sig = oem->signature;
454 	if (!sig)
455 		return(-2);
456 
457 	from = oem->range.from;
458 	to = oem->range.to;
459 	if ( (to<=from) || (from<BIOS_START) || (to>(BIOS_START+BIOS_SIZE)) )
460 		return(-3);
461 
462 	while (sig->anchor != NULL) {
463 		str = sig->anchor;
464 		len = strlen(str);
465 		off = sig->offset;
466 		tot = sig->totlen;
467 		/* make sure offset doesn't go beyond bios area */
468 		if ( (to+off)>(BIOS_START+BIOS_SIZE) ||
469 					((from+off)<BIOS_START) ) {
470 			printf("sys/i386/i386/bios.c: sig '%s' "
471 				"from 0x%0x to 0x%0x offset %d "
472 				"out of BIOS bounds 0x%0x - 0x%0x\n",
473 				str, from, to, off,
474 				BIOS_START, BIOS_START+BIOS_SIZE);
475 			return(-4);
476 		}
477 		/* make sure we don't overrun return buffer */
478 		if (idx + tot > maxlen - 1) {
479 			printf("sys/i386/i386/bios.c: sig '%s' "
480 				"idx %d + tot %d = %d > maxlen-1 %d\n",
481 				str, idx, tot, idx+tot, maxlen-1);
482 			return(-5);
483 		}
484 		bios_str = NULL;
485 		s = (u_char *)BIOS_PADDRTOVADDR(from);
486 		se = (u_char *)BIOS_PADDRTOVADDR(to-len);
487 		for (; s<se; s++) {
488 			if (!bcmp(str, s, len)) {
489 				bios_str = s;
490 				break;
491 			}
492 		}
493 		/*
494 		*  store pretty version of totlen bytes of bios string with
495 		*  given offset; 0x20 - 0x7E are printable; uniquify spaces
496 		*/
497 		if (bios_str) {
498 			for (i=0; i<tot; i++) {
499 				c = bios_str[i+off];
500 				if ( (c < 0x20) || (c > 0x7E) )
501 					c = ' ';
502 				if (idx == 0) {
503 					if (c != ' ')
504 						buffer[idx++] = c;
505 				} else if ( (c != ' ') ||
506 					((c == ' ') && (buffer[idx-1] != ' ')) )
507 						buffer[idx++] = c;
508 			}
509 		}
510 		sig++;
511 	}
512 	/* remove a final trailing space */
513 	if ( (idx > 1) && (buffer[idx-1] == ' ') )
514 		idx--;
515 	buffer[idx] = '\0';
516 	return (idx);
517 }
518 
519 #ifdef DEV_ISA
520 /*
521  * PnP BIOS interface; enumerate devices only known to the system
522  * BIOS and save information about them for later use.
523  */
524 
525 struct pnp_sysdev
526 {
527     u_int16_t	size;
528     u_int8_t	handle;
529     u_int32_t	devid;
530     u_int8_t	type[3];
531     u_int16_t	attrib;
532 #define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
533 #define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
534 #define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
535 #define PNPATTR_INPUT		(1<<3)	/* can be primary input */
536 #define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
537 #define PNPATTR_DOCK		(1<<5)	/* is a docking station */
538 #define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
539 #define PNPATTR_CONFIG_STATIC	(0)
540 #define PNPATTR_CONFIG_DYNAMIC	(1)
541 #define PNPATTR_CONFIG_DYNONLY	(3)
542 #define PNPATTR_CONFIG(a)	(((a) >> 7) & 0x3)
543     /* device-specific data comes here */
544     u_int8_t	devdata[0];
545 } __packed;
546 
547 /* We have to cluster arguments within a 64k range for the bios16 call */
548 struct pnp_sysdevargs
549 {
550     u_int16_t	next;
551     struct pnp_sysdev node;
552 };
553 
554 /*
555  * This function is called after the bus has assigned resource
556  * locations for a logical device.
557  */
558 static void
559 pnpbios_set_config(void *arg, struct isa_config *config, int enable)
560 {
561 }
562 
563 /*
564  * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
565  */
566 static void
567 pnpbios_identify(driver_t *driver, device_t parent)
568 {
569     struct PnPBIOS_table	*pt = PnPBIOStable;
570     struct bios_args		args;
571     struct pnp_sysdev		*pd;
572     struct pnp_sysdevargs	*pda;
573     u_int16_t			ndevs, bigdev;
574     int				error, currdev;
575     u_int8_t			*devnodebuf, tag;
576     u_int32_t			*devid, *compid;
577     int				idx, left;
578     device_t			dev;
579 
580     /* no PnP BIOS information */
581     if (pt == NULL)
582 	return;
583 
584     /* Check to see if ACPI is already active. */
585     dev = devclass_get_device(devclass_find("acpi"), 0);
586     if (dev != NULL && device_is_attached(dev))
587 	return;
588 
589     /* get count of PnP devices */
590     bzero(&args, sizeof(args));
591     args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
592     args.seg.code16.limit = 0xffff;		/* XXX ? */
593     args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
594     args.seg.data.limit = 0xffff;
595     args.entry = pt->pmentryoffset;
596 
597     if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff)) {
598 	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
599 	return;
600     }
601     ndevs &= 0xff;				/* clear high byte garbage */
602     if (bootverbose)
603 	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
604 
605     devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
606 			M_DEVBUF, M_NOWAIT);
607     if (devnodebuf == NULL) {
608 	printf("pnpbios: cannot allocate memory, bailing\n");
609 	return;
610     }
611     pda = (struct pnp_sysdevargs *)devnodebuf;
612     pd = &pda->node;
613 
614     for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
615 	bzero(pd, bigdev);
616 	pda->next = currdev;
617 	/* get current configuration */
618 	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, 1))) {
619 	    printf("pnpbios: error %d making BIOS16 call\n", error);
620 	    break;
621 	}
622 	if ((error = (args.r.eax & 0xff))) {
623 	    if (bootverbose)
624 		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
625 	    if (error & 0x80)
626 		break;
627 	}
628 	currdev = pda->next;
629 	if (pd->size < sizeof(struct pnp_sysdev)) {
630 	    printf("pnpbios: bogus system node data, aborting scan\n");
631 	    break;
632 	}
633 
634 	/*
635 	 * Ignore PICs so that we don't have to worry about the PICs
636 	 * claiming IRQs to prevent their use.  The PIC drivers
637 	 * already ensure that invalid IRQs are not used.
638 	 */
639 	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0000"))	/* ISA PIC */
640 	    continue;
641 	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0003"))	/* APIC */
642 	    continue;
643 
644 	/* Add the device and parse its resources */
645 	dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNPBIOS, NULL, -1);
646 	isa_set_vendorid(dev, pd->devid);
647 	isa_set_logicalid(dev, pd->devid);
648 	/*
649 	 * It appears that some PnP BIOS doesn't allow us to re-enable
650 	 * the embedded system device once it is disabled.  We shall
651 	 * mark all system device nodes as "cannot be disabled", regardless
652 	 * of actual settings in the device attribute byte.
653 	 * XXX
654 	isa_set_configattr(dev,
655 	    ((pd->attrib & PNPATTR_NODISABLE) ?  0 : ISACFGATTR_CANDISABLE) |
656 	    ((!(pd->attrib & PNPATTR_NOCONFIG) &&
657 		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
658 		? ISACFGATTR_DYNAMIC : 0));
659 	 */
660 	isa_set_configattr(dev,
661 	    (!(pd->attrib & PNPATTR_NOCONFIG) &&
662 		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
663 		? ISACFGATTR_DYNAMIC : 0);
664 	isa_set_pnpbios_handle(dev, pd->handle);
665 	ISA_SET_CONFIG_CALLBACK(parent, dev, pnpbios_set_config, 0);
666 	pnp_parse_resources(dev, &pd->devdata[0],
667 	    pd->size - sizeof(struct pnp_sysdev), 0);
668 	if (!device_get_desc(dev))
669 	    device_set_desc_copy(dev, pnp_eisaformat(pd->devid));
670 
671 	/* Find device IDs */
672 	devid = &pd->devid;
673 	compid = NULL;
674 
675 	/* look for a compatible device ID too */
676 	left = pd->size - sizeof(struct pnp_sysdev);
677 	idx = 0;
678 	while (idx < left) {
679 	    tag = pd->devdata[idx++];
680 	    if (PNP_RES_TYPE(tag) == 0) {
681 		/* Small resource */
682 		switch (PNP_SRES_NUM(tag)) {
683 		case PNP_TAG_COMPAT_DEVICE:
684 		    compid = (u_int32_t *)(pd->devdata + idx);
685 		    if (bootverbose)
686 			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
687 		    /* FALLTHROUGH */
688 		case PNP_TAG_END:
689 		    idx = left;
690 		    break;
691 		default:
692 		    idx += PNP_SRES_LEN(tag);
693 		    break;
694 		}
695 	    } else
696 		/* Large resource, skip it */
697 		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
698 	}
699 	if (bootverbose) {
700 	    printf("pnpbios: handle %d device ID %s (%08x)",
701 		   pd->handle, pnp_eisaformat(*devid), *devid);
702 	    if (compid != NULL)
703 		printf(" compat ID %s (%08x)",
704 		       pnp_eisaformat(*compid), *compid);
705 	    printf("\n");
706 	}
707     }
708 }
709 
710 static device_method_t pnpbios_methods[] = {
711 	/* Device interface */
712 	DEVMETHOD(device_identify,	pnpbios_identify),
713 	{ 0, 0 }
714 };
715 
716 static driver_t pnpbios_driver = {
717 	"pnpbios",
718 	pnpbios_methods,
719 	1,			/* no softc */
720 };
721 
722 DRIVER_MODULE(pnpbios, isa, pnpbios_driver, 0, 0);
723 #endif /* DEV_ISA */
724