bios.c revision 330897
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD: stable/11/sys/i386/i386/bios.c 330897 2018-03-14 03:19:51Z eadler $");
32
33/*
34 * Code for dealing with the BIOS in x86 PC systems.
35 */
36
37#include "opt_isa.h"
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/kernel.h>
42#include <sys/malloc.h>
43#include <sys/module.h>
44#include <sys/bus.h>
45#include <sys/pcpu.h>
46#include <vm/vm.h>
47#include <vm/pmap.h>
48#include <machine/md_var.h>
49#include <machine/segments.h>
50#include <machine/stdarg.h>
51#include <machine/vmparam.h>
52#include <machine/pc/bios.h>
53#ifdef DEV_ISA
54#include <isa/isavar.h>
55#include <isa/pnpreg.h>
56#include <isa/pnpvar.h>
57#endif
58
59#define BIOS_START	0xe0000
60#define BIOS_SIZE	0x20000
61
62/* exported lookup results */
63struct bios32_SDentry		PCIbios;
64
65static struct PnPBIOS_table	*PnPBIOStable;
66
67static u_int			bios32_SDCI;
68
69/* start fairly early */
70static void			bios32_init(void *junk);
71SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
72
73/*
74 * bios32_init
75 *
76 * Locate various bios32 entities.
77 */
78static void
79bios32_init(void *junk)
80{
81    u_long			sigaddr;
82    struct bios32_SDheader	*sdh;
83    struct PnPBIOS_table	*pt;
84    u_int8_t			ck, *cv;
85    int				i;
86    char			*p;
87
88    /*
89     * BIOS32 Service Directory, PCI BIOS
90     */
91
92    /* look for the signature */
93    if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
94
95	/* get a virtual pointer to the structure */
96	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
97	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
98	    ck += cv[i];
99	}
100	/* If checksum is OK, enable use of the entrypoint */
101	if ((ck == 0) && (BIOS_START <= sdh->entry ) &&
102	    (sdh->entry < (BIOS_START + BIOS_SIZE))) {
103	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
104	    if (bootverbose) {
105		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
106		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
107		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
108	    }
109
110	    /* Allow user override of PCI BIOS search */
111	    if (((p = kern_getenv("machdep.bios.pci")) == NULL) || strcmp(p, "disable")) {
112
113		/* See if there's a PCI BIOS entrypoint here */
114		PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
115		if (!bios32_SDlookup(&PCIbios) && bootverbose)
116		    printf("pcibios: PCI BIOS entry at 0x%x+0x%x\n", PCIbios.base, PCIbios.entry);
117	    }
118	    if (p != NULL)
119		    freeenv(p);
120	} else {
121	    printf("bios32: Bad BIOS32 Service Directory\n");
122	}
123    }
124
125    /*
126     * PnP BIOS
127     *
128     * Allow user override of PnP BIOS search
129     */
130    if ((((p = kern_getenv("machdep.bios.pnp")) == NULL) || strcmp(p, "disable")) &&
131	((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0)) {
132
133	/* get a virtual pointer to the structure */
134	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
135	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
136	    ck += cv[i];
137	}
138	/* If checksum is OK, enable use of the entrypoint */
139	if (ck == 0) {
140	    PnPBIOStable = pt;
141	    if (bootverbose) {
142		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
143		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
144		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
145		if ((pt->control & 0x3) == 0x01)
146		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
147		if (pt->oemdevid != 0)
148		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
149
150	    }
151	} else {
152	    printf("pnpbios: Bad PnP BIOS data checksum\n");
153	}
154    }
155    if (p != NULL)
156	    freeenv(p);
157    if (bootverbose) {
158	    /* look for other know signatures */
159	    printf("Other BIOS signatures found:\n");
160    }
161}
162
163/*
164 * bios32_SDlookup
165 *
166 * Query the BIOS32 Service Directory for the service named in (ent),
167 * returns nonzero if the lookup fails.  The caller must fill in
168 * (ent->ident), the remainder are populated on a successful lookup.
169 */
170int
171bios32_SDlookup(struct bios32_SDentry *ent)
172{
173    struct bios_regs args;
174
175    if (bios32_SDCI == 0)
176	return (1);
177
178    args.eax = ent->ident.id;		/* set up arguments */
179    args.ebx = args.ecx = args.edx = 0;
180    bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
181    if ((args.eax & 0xff) == 0) {	/* success? */
182	ent->base = args.ebx;
183	ent->len = args.ecx;
184	ent->entry = args.edx;
185	ent->ventry = BIOS_PADDRTOVADDR(ent->base + ent->entry);
186	return (0);			/* all OK */
187    }
188    return (1);				/* failed */
189}
190
191
192/*
193 * bios_sigsearch
194 *
195 * Search some or all of the BIOS region for a signature string.
196 *
197 * (start)	Optional offset returned from this function
198 *		(for searching for multiple matches), or NULL
199 *		to start the search from the base of the BIOS.
200 *		Note that this will be a _physical_ address in
201 *		the range 0xe0000 - 0xfffff.
202 * (sig)	is a pointer to the byte(s) of the signature.
203 * (siglen)	number of bytes in the signature.
204 * (paralen)	signature paragraph (alignment) size.
205 * (sigofs)	offset of the signature within the paragraph.
206 *
207 * Returns the _physical_ address of the found signature, 0 if the
208 * signature was not found.
209 */
210
211u_int32_t
212bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
213{
214    u_char	*sp, *end;
215
216    /* compute the starting address */
217    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
218	sp = (char *)BIOS_PADDRTOVADDR(start);
219    } else if (start == 0) {
220	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
221    } else {
222	return 0;				/* bogus start address */
223    }
224
225    /* compute the end address */
226    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
227
228    /* loop searching */
229    while ((sp + sigofs + siglen) < end) {
230
231	/* compare here */
232	if (!bcmp(sp + sigofs, sig, siglen)) {
233	    /* convert back to physical address */
234	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
235	}
236	sp += paralen;
237    }
238    return(0);
239}
240
241/*
242 * do not staticize, used by bioscall.s
243 */
244union {
245    struct {
246	u_short	offset;
247	u_short	segment;
248    } vec16;
249    struct {
250	u_int	offset;
251	u_short	segment;
252    } vec32;
253} bioscall_vector;			/* bios jump vector */
254
255void
256set_bios_selectors(struct bios_segments *seg, int flags)
257{
258    struct soft_segment_descriptor ssd = {
259	0,			/* segment base address (overwritten) */
260	0,			/* length (overwritten) */
261	SDT_MEMERA,		/* segment type (overwritten) */
262	0,			/* priority level */
263	1,			/* descriptor present */
264	0, 0,
265	1,			/* descriptor size (overwritten) */
266	0			/* granularity == byte units */
267    };
268    union descriptor *p_gdt;
269
270#ifdef SMP
271    p_gdt = &gdt[PCPU_GET(cpuid) * NGDT];
272#else
273    p_gdt = gdt;
274#endif
275
276    ssd.ssd_base = seg->code32.base;
277    ssd.ssd_limit = seg->code32.limit;
278    ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
279
280    ssd.ssd_def32 = 0;
281    if (flags & BIOSCODE_FLAG) {
282	ssd.ssd_base = seg->code16.base;
283	ssd.ssd_limit = seg->code16.limit;
284	ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
285    }
286
287    ssd.ssd_type = SDT_MEMRWA;
288    if (flags & BIOSDATA_FLAG) {
289	ssd.ssd_base = seg->data.base;
290	ssd.ssd_limit = seg->data.limit;
291	ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
292    }
293
294    if (flags & BIOSUTIL_FLAG) {
295	ssd.ssd_base = seg->util.base;
296	ssd.ssd_limit = seg->util.limit;
297	ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
298    }
299
300    if (flags & BIOSARGS_FLAG) {
301	ssd.ssd_base = seg->args.base;
302	ssd.ssd_limit = seg->args.limit;
303	ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
304    }
305}
306
307extern int vm86pa;
308extern void bios16_jmp(void);
309
310/*
311 * this routine is really greedy with selectors, and uses 5:
312 *
313 * 32-bit code selector:	to return to kernel
314 * 16-bit code selector:	for running code
315 *        data selector:	for 16-bit data
316 *        util selector:	extra utility selector
317 *        args selector:	to handle pointers
318 *
319 * the util selector is set from the util16 entry in bios16_args, if a
320 * "U" specifier is seen.
321 *
322 * See <machine/pc/bios.h> for description of format specifiers
323 */
324int
325bios16(struct bios_args *args, char *fmt, ...)
326{
327    char	*p, *stack, *stack_top;
328    va_list 	ap;
329    int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
330    u_int 	i, arg_start, arg_end;
331    pt_entry_t	*pte;
332    pd_entry_t	*ptd;
333
334    arg_start = 0xffffffff;
335    arg_end = 0;
336
337    /*
338     * Some BIOS entrypoints attempt to copy the largest-case
339     * argument frame (in order to generalise handling for
340     * different entry types).  If our argument frame is
341     * smaller than this, the BIOS will reach off the top of
342     * our constructed stack segment.  Pad the top of the stack
343     * with some garbage to avoid this.
344     */
345    stack = (caddr_t)PAGE_SIZE - 32;
346
347    va_start(ap, fmt);
348    for (p = fmt; p && *p; p++) {
349	switch (*p) {
350	case 'p':			/* 32-bit pointer */
351	    i = va_arg(ap, u_int);
352	    arg_start = min(arg_start, i);
353	    arg_end = max(arg_end, i);
354	    flags |= BIOSARGS_FLAG;
355	    stack -= 4;
356	    break;
357
358	case 'i':			/* 32-bit integer */
359	    i = va_arg(ap, u_int);
360	    stack -= 4;
361	    break;
362
363	case 'U':			/* 16-bit selector */
364	    flags |= BIOSUTIL_FLAG;
365	    /* FALLTHROUGH */
366	case 'D':			/* 16-bit selector */
367	case 'C':			/* 16-bit selector */
368	    stack -= 2;
369	    break;
370
371	case 's':			/* 16-bit integer passed as an int */
372	    i = va_arg(ap, int);
373	    stack -= 2;
374	    break;
375
376	default:
377	    va_end(ap);
378	    return (EINVAL);
379	}
380    }
381    va_end(ap);
382
383    if (flags & BIOSARGS_FLAG) {
384	if (arg_end - arg_start > ctob(16))
385	    return (EACCES);
386	args->seg.args.base = arg_start;
387	args->seg.args.limit = 0xffff;
388    }
389
390    args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
391    args->seg.code32.limit = 0xffff;
392
393    ptd = (pd_entry_t *)rcr3();
394#if defined(PAE) || defined(PAE_TABLES)
395    if (ptd == IdlePDPT)
396#else
397    if (ptd == IdlePTD)
398#endif
399    {
400	/*
401	 * no page table, so create one and install it.
402	 */
403	pte = (pt_entry_t *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
404	ptd = (pd_entry_t *)((u_int)IdlePTD + KERNBASE);
405	*pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
406	*ptd = vtophys(pte) | PG_RW | PG_V;
407    } else {
408	/*
409	 * this is a user-level page table
410	 */
411	pte = PTmap;
412	*pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
413    }
414    pmap_invalidate_all(kernel_pmap);	/* XXX insurance for now */
415
416    stack_top = stack;
417    va_start(ap, fmt);
418    for (p = fmt; p && *p; p++) {
419	switch (*p) {
420	case 'p':			/* 32-bit pointer */
421	    i = va_arg(ap, u_int);
422	    *(u_int *)stack = (i - arg_start) |
423		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
424	    stack += 4;
425	    break;
426
427	case 'i':			/* 32-bit integer */
428	    i = va_arg(ap, u_int);
429	    *(u_int *)stack = i;
430	    stack += 4;
431	    break;
432
433	case 'U':			/* 16-bit selector */
434	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
435	    stack += 2;
436	    break;
437
438	case 'D':			/* 16-bit selector */
439	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
440	    stack += 2;
441	    break;
442
443	case 'C':			/* 16-bit selector */
444	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
445	    stack += 2;
446	    break;
447
448	case 's':			/* 16-bit integer passed as an int */
449	    i = va_arg(ap, int);
450	    *(u_short *)stack = i;
451	    stack += 2;
452	    break;
453
454	default:
455	    va_end(ap);
456	    return (EINVAL);
457	}
458    }
459    va_end(ap);
460
461    set_bios_selectors(&args->seg, flags);
462    bioscall_vector.vec16.offset = (u_short)args->entry;
463    bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
464
465    i = bios16_call(&args->r, stack_top);
466
467    if (pte == PTmap) {
468	*pte = 0;			/* remove entry */
469	/*
470	 * XXX only needs to be invlpg(0) but that doesn't work on the 386
471	 */
472	pmap_invalidate_all(kernel_pmap);
473    } else {
474	*ptd = 0;			/* remove page table */
475	/*
476	 * XXX only needs to be invlpg(0) but that doesn't work on the 386
477	 */
478	pmap_invalidate_all(kernel_pmap);
479	free(pte, M_TEMP);		/* ... and free it */
480    }
481    return (i);
482}
483
484int
485bios_oem_strings(struct bios_oem *oem, u_char *buffer, size_t maxlen)
486{
487	size_t idx = 0;
488	struct bios_oem_signature *sig;
489	u_int from, to;
490	u_char c, *s, *se, *str, *bios_str;
491	size_t i, off, len, tot;
492
493	if ( !oem || !buffer || maxlen<2 )
494		return(-1);
495
496	sig = oem->signature;
497	if (!sig)
498		return(-2);
499
500	from = oem->range.from;
501	to = oem->range.to;
502	if ( (to<=from) || (from<BIOS_START) || (to>(BIOS_START+BIOS_SIZE)) )
503		return(-3);
504
505	while (sig->anchor != NULL) {
506		str = sig->anchor;
507		len = strlen(str);
508		off = sig->offset;
509		tot = sig->totlen;
510		/* make sure offset doesn't go beyond bios area */
511		if ( (to+off)>(BIOS_START+BIOS_SIZE) ||
512					((from+off)<BIOS_START) ) {
513			printf("sys/i386/i386/bios.c: sig '%s' "
514				"from 0x%0x to 0x%0x offset %d "
515				"out of BIOS bounds 0x%0x - 0x%0x\n",
516				str, from, to, off,
517				BIOS_START, BIOS_START+BIOS_SIZE);
518			return(-4);
519		}
520		/* make sure we don't overrun return buffer */
521		if (idx + tot > maxlen - 1) {
522			printf("sys/i386/i386/bios.c: sig '%s' "
523				"idx %d + tot %d = %d > maxlen-1 %d\n",
524				str, idx, tot, idx+tot, maxlen-1);
525			return(-5);
526		}
527		bios_str = NULL;
528		s = (u_char *)BIOS_PADDRTOVADDR(from);
529		se = (u_char *)BIOS_PADDRTOVADDR(to-len);
530		for (; s<se; s++) {
531			if (!bcmp(str, s, len)) {
532				bios_str = s;
533				break;
534			}
535		}
536		/*
537		*  store pretty version of totlen bytes of bios string with
538		*  given offset; 0x20 - 0x7E are printable; uniquify spaces
539		*/
540		if (bios_str) {
541			for (i=0; i<tot; i++) {
542				c = bios_str[i+off];
543				if ( (c < 0x20) || (c > 0x7E) )
544					c = ' ';
545				if (idx == 0) {
546					if (c != ' ')
547						buffer[idx++] = c;
548				} else if ( (c != ' ') ||
549					((c == ' ') && (buffer[idx-1] != ' ')) )
550						buffer[idx++] = c;
551			}
552		}
553		sig++;
554	}
555	/* remove a final trailing space */
556	if ( (idx > 1) && (buffer[idx-1] == ' ') )
557		idx--;
558	buffer[idx] = '\0';
559	return (idx);
560}
561
562#ifdef DEV_ISA
563/*
564 * PnP BIOS interface; enumerate devices only known to the system
565 * BIOS and save information about them for later use.
566 */
567
568struct pnp_sysdev
569{
570    u_int16_t	size;
571    u_int8_t	handle;
572    u_int32_t	devid;
573    u_int8_t	type[3];
574    u_int16_t	attrib;
575#define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
576#define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
577#define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
578#define PNPATTR_INPUT		(1<<3)	/* can be primary input */
579#define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
580#define PNPATTR_DOCK		(1<<5)	/* is a docking station */
581#define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
582#define PNPATTR_CONFIG_STATIC	(0)
583#define PNPATTR_CONFIG_DYNAMIC	(1)
584#define PNPATTR_CONFIG_DYNONLY	(3)
585#define PNPATTR_CONFIG(a)	(((a) >> 7) & 0x3)
586    /* device-specific data comes here */
587    u_int8_t	devdata[0];
588} __packed;
589
590/* We have to cluster arguments within a 64k range for the bios16 call */
591struct pnp_sysdevargs
592{
593    u_int16_t	next;
594    struct pnp_sysdev node;
595};
596
597/*
598 * This function is called after the bus has assigned resource
599 * locations for a logical device.
600 */
601static void
602pnpbios_set_config(void *arg, struct isa_config *config, int enable)
603{
604}
605
606/*
607 * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
608 */
609static void
610pnpbios_identify(driver_t *driver, device_t parent)
611{
612    struct PnPBIOS_table	*pt = PnPBIOStable;
613    struct bios_args		args;
614    struct pnp_sysdev		*pd;
615    struct pnp_sysdevargs	*pda;
616    u_int16_t			ndevs, bigdev;
617    int				error, currdev;
618    u_int8_t			*devnodebuf, tag;
619    u_int32_t			*devid, *compid;
620    int				idx, left;
621    device_t			dev;
622
623    /* no PnP BIOS information */
624    if (pt == NULL)
625	return;
626
627    /* Check to see if ACPI is already active. */
628    dev = devclass_get_device(devclass_find("acpi"), 0);
629    if (dev != NULL && device_is_attached(dev))
630	return;
631
632    /* get count of PnP devices */
633    bzero(&args, sizeof(args));
634    args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
635    args.seg.code16.limit = 0xffff;		/* XXX ? */
636    args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
637    args.seg.data.limit = 0xffff;
638    args.entry = pt->pmentryoffset;
639
640    if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff)) {
641	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
642	return;
643    }
644    ndevs &= 0xff;				/* clear high byte garbage */
645    if (bootverbose)
646	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
647
648    devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
649			M_DEVBUF, M_NOWAIT);
650    if (devnodebuf == NULL) {
651	printf("pnpbios: cannot allocate memory, bailing\n");
652	return;
653    }
654    pda = (struct pnp_sysdevargs *)devnodebuf;
655    pd = &pda->node;
656
657    for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
658
659	bzero(pd, bigdev);
660	pda->next = currdev;
661	/* get current configuration */
662	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, 1))) {
663	    printf("pnpbios: error %d making BIOS16 call\n", error);
664	    break;
665	}
666	if ((error = (args.r.eax & 0xff))) {
667	    if (bootverbose)
668		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
669	    if (error & 0x80)
670		break;
671	}
672	currdev = pda->next;
673	if (pd->size < sizeof(struct pnp_sysdev)) {
674	    printf("pnpbios: bogus system node data, aborting scan\n");
675	    break;
676	}
677
678	/*
679	 * Ignore PICs so that we don't have to worry about the PICs
680	 * claiming IRQs to prevent their use.  The PIC drivers
681	 * already ensure that invalid IRQs are not used.
682	 */
683	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0000"))	/* ISA PIC */
684	    continue;
685	if (!strcmp(pnp_eisaformat(pd->devid), "PNP0003"))	/* APIC */
686	    continue;
687
688	/* Add the device and parse its resources */
689	dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNPBIOS, NULL, -1);
690	isa_set_vendorid(dev, pd->devid);
691	isa_set_logicalid(dev, pd->devid);
692	/*
693	 * It appears that some PnP BIOS doesn't allow us to re-enable
694	 * the embedded system device once it is disabled.  We shall
695	 * mark all system device nodes as "cannot be disabled", regardless
696	 * of actual settings in the device attribute byte.
697	 * XXX
698	isa_set_configattr(dev,
699	    ((pd->attrib & PNPATTR_NODISABLE) ?  0 : ISACFGATTR_CANDISABLE) |
700	    ((!(pd->attrib & PNPATTR_NOCONFIG) &&
701		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
702		? ISACFGATTR_DYNAMIC : 0));
703	 */
704	isa_set_configattr(dev,
705	    (!(pd->attrib & PNPATTR_NOCONFIG) &&
706		PNPATTR_CONFIG(pd->attrib) != PNPATTR_CONFIG_STATIC)
707		? ISACFGATTR_DYNAMIC : 0);
708	isa_set_pnpbios_handle(dev, pd->handle);
709	ISA_SET_CONFIG_CALLBACK(parent, dev, pnpbios_set_config, 0);
710	pnp_parse_resources(dev, &pd->devdata[0],
711	    pd->size - sizeof(struct pnp_sysdev), 0);
712	if (!device_get_desc(dev))
713	    device_set_desc_copy(dev, pnp_eisaformat(pd->devid));
714
715	/* Find device IDs */
716	devid = &pd->devid;
717	compid = NULL;
718
719	/* look for a compatible device ID too */
720	left = pd->size - sizeof(struct pnp_sysdev);
721	idx = 0;
722	while (idx < left) {
723	    tag = pd->devdata[idx++];
724	    if (PNP_RES_TYPE(tag) == 0) {
725		/* Small resource */
726		switch (PNP_SRES_NUM(tag)) {
727		case PNP_TAG_COMPAT_DEVICE:
728		    compid = (u_int32_t *)(pd->devdata + idx);
729		    if (bootverbose)
730			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
731		    /* FALLTHROUGH */
732		case PNP_TAG_END:
733		    idx = left;
734		    break;
735		default:
736		    idx += PNP_SRES_LEN(tag);
737		    break;
738		}
739	    } else
740		/* Large resource, skip it */
741		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
742	}
743	if (bootverbose) {
744	    printf("pnpbios: handle %d device ID %s (%08x)",
745		   pd->handle, pnp_eisaformat(*devid), *devid);
746	    if (compid != NULL)
747		printf(" compat ID %s (%08x)",
748		       pnp_eisaformat(*compid), *compid);
749	    printf("\n");
750	}
751    }
752}
753
754static device_method_t pnpbios_methods[] = {
755	/* Device interface */
756	DEVMETHOD(device_identify,	pnpbios_identify),
757
758	{ 0, 0 }
759};
760
761static driver_t pnpbios_driver = {
762	"pnpbios",
763	pnpbios_methods,
764	1,			/* no softc */
765};
766
767static devclass_t pnpbios_devclass;
768
769DRIVER_MODULE(pnpbios, isa, pnpbios_driver, pnpbios_devclass, 0, 0);
770#endif /* DEV_ISA */
771