bios.c revision 49996 
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 *      $Id: bios.c,v 1.16 1999/08/17 07:10:29 msmith Exp $
28 */
29
30/*
31 * Code for dealing with the BIOS in x86 PC systems.
32 */
33
34#include <sys/param.h>
35#include <sys/proc.h>
36#include <sys/systm.h>
37#include <sys/kernel.h>
38#include <sys/malloc.h>
39#include <vm/vm.h>
40#include <vm/pmap.h>
41#include <machine/md_var.h>
42#include <machine/segments.h>
43#include <machine/stdarg.h>
44#include <machine/tss.h>
45#include <machine/vmparam.h>
46#include <machine/pc/bios.h>
47#include <i386/isa/isa_device.h>
48#include <i386/isa/pnp.h>
49
50#define BIOS_START	0xe0000
51#define BIOS_SIZE	0x20000
52
53/* exported lookup results */
54struct bios32_SDentry		PCIbios = {entry : 0};
55struct PnPBIOS_table		*PnPBIOStable = 0;
56
57static u_int			bios32_SDCI = 0;
58
59/* start fairly early */
60static void			bios32_init(void *junk);
61SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
62
63static void	pnpbios_scan(void);
64static char 	*pnp_eisaformat(u_int8_t *data);
65
66
67/*
68 * bios32_init
69 *
70 * Locate various bios32 entities.
71 */
72static void
73bios32_init(void *junk)
74{
75    u_long			sigaddr;
76    struct bios32_SDheader	*sdh;
77    struct PnPBIOS_table	*pt;
78    u_int8_t			ck, *cv;
79    int				i;
80
81
82    /*
83     * BIOS32 Service Directory
84     */
85
86    /* look for the signature */
87    if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
88
89	/* get a virtual pointer to the structure */
90	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
91	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
92	    ck += cv[i];
93	}
94	/* If checksum is OK, enable use of the entrypoint */
95	if ((ck == 0) && (sdh->entry < (BIOS_START + BIOS_SIZE))) {
96	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
97	    if (bootverbose) {
98		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
99		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
100		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
101	    }
102	    /* See if there's a PCI BIOS entrypoint here */
103	    PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
104	    if (!bios32_SDlookup(&PCIbios) && bootverbose)
105		printf("pcibios: PCI BIOS entry at 0x%x\n", PCIbios.entry);
106	} else {
107	    printf("bios32: Bad BIOS32 Service Directory\n");
108	}
109    }
110
111    /*
112     * PnP BIOS
113     */
114    if ((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0) {
115
116	/* get a virtual pointer to the structure */
117	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
118	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
119	    ck += cv[i];
120	}
121	/* If checksum is OK, enable use of the entrypoint */
122	if (ck == 0) {
123	    PnPBIOStable = pt;
124	    if (bootverbose) {
125		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
126		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
127		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
128		if ((pt->control & 0x3) == 0x01)
129		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
130		if (pt->oemdevid != 0)
131		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
132
133	    }
134	    pnpbios_scan();
135	} else {
136	    printf("pnpbios: Bad PnP BIOS data checksum\n");
137	}
138    }
139
140    if (bootverbose) {
141	    /* look for other know signatures */
142	    printf("Other BIOS signatures found:\n");
143	    printf("ACPI: %08x\n", bios_sigsearch(0, "RST PTR", 8, 16, 0));
144    }
145}
146
147/*
148 * bios32_SDlookup
149 *
150 * Query the BIOS32 Service Directory for the service named in (ent),
151 * returns nonzero if the lookup fails.  The caller must fill in
152 * (ent->ident), the remainder are populated on a successful lookup.
153 */
154int
155bios32_SDlookup(struct bios32_SDentry *ent)
156{
157    struct bios_regs args;
158
159    if (bios32_SDCI == 0)
160	return (1);
161
162    args.eax = ent->ident.id;		/* set up arguments */
163    args.ebx = args.ecx = args.edx = 0;
164    bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
165    if ((args.eax & 0xff) == 0) {	/* success? */
166	ent->base = args.ebx;
167	ent->len = args.ecx;
168	ent->entry = args.edx;
169	return (0);			/* all OK */
170    }
171    return (1);				/* failed */
172}
173
174
175/*
176 * bios_sigsearch
177 *
178 * Search some or all of the BIOS region for a signature string.
179 *
180 * (start)	Optional offset returned from this function
181 *		(for searching for multiple matches), or NULL
182 *		to start the search from the base of the BIOS.
183 *		Note that this will be a _physical_ address in
184 *		the range 0xe0000 - 0xfffff.
185 * (sig)	is a pointer to the byte(s) of the signature.
186 * (siglen)	number of bytes in the signature.
187 * (paralen)	signature paragraph (alignment) size.
188 * (sigofs)	offset of the signature within the paragraph.
189 *
190 * Returns the _physical_ address of the found signature, 0 if the
191 * signature was not found.
192 */
193
194u_int32_t
195bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
196{
197    u_char	*sp, *end;
198
199    /* compute the starting address */
200    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
201	sp = (char *)BIOS_PADDRTOVADDR(start);
202    } else if (start == 0) {
203	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
204    } else {
205	return 0;				/* bogus start address */
206    }
207
208    /* compute the end address */
209    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
210
211    /* loop searching */
212    while ((sp + sigofs + siglen) < end) {
213
214	/* compare here */
215	if (!bcmp(sp + sigofs, sig, siglen)) {
216	    /* convert back to physical address */
217	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
218	}
219	sp += paralen;
220    }
221    return(0);
222}
223
224/*
225 * do not staticize, used by bioscall.s
226 */
227union {
228    struct {
229	u_short	offset;
230	u_short	segment;
231    } vec16;
232    struct {
233	u_int	offset;
234	u_short	segment;
235    } vec32;
236} bioscall_vector;			/* bios jump vector */
237
238void
239set_bios_selectors(struct bios_segments *seg, int flags)
240{
241    static u_int curgen = 1;
242    struct soft_segment_descriptor ssd = {
243	0,			/* segment base address (overwritten) */
244	0,			/* length (overwritten) */
245	SDT_MEMERA,		/* segment type (overwritten) */
246	0,			/* priority level */
247	1,			/* descriptor present */
248	0, 0,
249	1,			/* descriptor size (overwritten) */
250	0			/* granularity == byte units */
251    };
252
253    if (seg->generation == curgen)
254	return;
255    if (++curgen == 0)
256	curgen = 1;
257    seg->generation = curgen;
258
259    ssd.ssd_base = seg->code32.base;
260    ssd.ssd_limit = seg->code32.limit;
261    ssdtosd(&ssd, &gdt[GBIOSCODE32_SEL].sd);
262
263    ssd.ssd_def32 = 0;
264    if (flags & BIOSCODE_FLAG) {
265	ssd.ssd_base = seg->code16.base;
266	ssd.ssd_limit = seg->code16.limit;
267	ssdtosd(&ssd, &gdt[GBIOSCODE16_SEL].sd);
268    }
269
270    ssd.ssd_type = SDT_MEMRWA;
271    if (flags & BIOSDATA_FLAG) {
272	ssd.ssd_base = seg->data.base;
273	ssd.ssd_limit = seg->data.limit;
274	ssdtosd(&ssd, &gdt[GBIOSDATA_SEL].sd);
275    }
276
277    if (flags & BIOSUTIL_FLAG) {
278	ssd.ssd_base = seg->util.base;
279	ssd.ssd_limit = seg->util.limit;
280	ssdtosd(&ssd, &gdt[GBIOSUTIL_SEL].sd);
281    }
282
283    if (flags & BIOSARGS_FLAG) {
284	ssd.ssd_base = seg->args.base;
285	ssd.ssd_limit = seg->args.limit;
286	ssdtosd(&ssd, &gdt[GBIOSARGS_SEL].sd);
287    }
288}
289
290/*
291 * for pointers, we don't know how much space is supposed to be allocated,
292 * so we assume a minimum size of 256 bytes.  If more than this is needed,
293 * then this can be revisited, such as adding a length specifier.
294 */
295#define	ASSUMED_ARGSIZE		256
296
297extern int vm86pa;
298
299/*
300 * this routine is really greedy with selectors, and uses 5:
301 *
302 * 32-bit code selector:	to return to kernel
303 * 16-bit code selector:	for running code
304 *        data selector:	for 16-bit data
305 *        util selector:	extra utility selector
306 *        args selector:	to handle pointers
307 *
308 * the util selector is set from the util16 entry in bios16_args, if a
309 * "U" specifier is seen.
310 *
311 * See <machine/pc/bios.h> for description of format specifiers
312 */
313int
314bios16(struct bios_args *args, char *fmt, ...)
315{
316    char	*p, *stack, *stack_top;
317    va_list 	ap;
318    int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
319    u_int 	i, arg_start, arg_end;
320    u_int 	*pte, *ptd;
321
322    arg_start = 0xffffffff;
323    arg_end = 0;
324
325    stack = (caddr_t)PAGE_SIZE;
326    va_start(ap, fmt);
327    for (p = fmt; p && *p; p++) {
328	switch (*p) {
329	case 'p':			/* 32-bit pointer */
330	    i = va_arg(ap, u_int);
331	    arg_start = min(arg_start, i);
332	    arg_end = max(arg_end, i + ASSUMED_ARGSIZE);
333	    flags |= BIOSARGS_FLAG;
334	    stack -= 4;
335	    break;
336
337	case 'i':			/* 32-bit integer */
338	    i = va_arg(ap, u_int);
339	    stack -= 4;
340	    break;
341
342	case 'U':			/* 16-bit selector */
343	    flags |= BIOSUTIL_FLAG;
344	    /* FALLTHROUGH */
345	case 'D':			/* 16-bit selector */
346	case 'C':			/* 16-bit selector */
347	    stack -= 2;
348	    break;
349
350	case 's':			/* 16-bit integer */
351	    i = va_arg(ap, u_short);
352	    stack -= 2;
353	    break;
354
355	default:
356	    return (EINVAL);
357	}
358    }
359
360    if (flags & BIOSARGS_FLAG) {
361	if (arg_end - arg_start > ctob(16))
362	    return (EACCES);
363	args->seg.args.base = arg_start;
364	args->seg.args.limit = arg_end - arg_start;
365    }
366
367    args->seg.code32.base = (u_int)&bios16_call & PG_FRAME;
368    args->seg.code32.limit = 0xffff;
369
370    ptd = (u_int *)rcr3();
371    if (ptd == IdlePTD) {
372	/*
373	 * no page table, so create one and install it.
374	 */
375	pte = (u_int *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
376	ptd = (u_int *)((u_int)ptd + KERNBASE);
377	*ptd = vtophys(pte) | PG_RW | PG_V;
378    } else {
379	/*
380	 * this is a user-level page table
381	 */
382	pte = (u_int *)&PTmap;
383    }
384    /*
385     * install pointer to page 0.  we don't need to flush the tlb,
386     * since there should not be a previous mapping for page 0.
387     */
388    *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
389
390    stack_top = stack;
391    va_start(ap, fmt);
392    for (p = fmt; p && *p; p++) {
393	switch (*p) {
394	case 'p':			/* 32-bit pointer */
395	    i = va_arg(ap, u_int);
396	    *(u_int *)stack = (i - arg_start) |
397		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
398	    stack += 4;
399	    break;
400
401	case 'i':			/* 32-bit integer */
402	    i = va_arg(ap, u_int);
403	    *(u_int *)stack = i;
404	    stack += 4;
405	    break;
406
407	case 'U':			/* 16-bit selector */
408	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
409	    stack += 2;
410	    break;
411
412	case 'D':			/* 16-bit selector */
413	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
414	    stack += 2;
415	    break;
416
417	case 'C':			/* 16-bit selector */
418	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
419	    stack += 2;
420	    break;
421
422	case 's':			/* 16-bit integer */
423	    i = va_arg(ap, u_short);
424	    *(u_short *)stack = i;
425	    stack += 2;
426	    break;
427
428	default:
429	    return (EINVAL);
430	}
431    }
432
433    args->seg.generation = 0;			/* reload selectors */
434    set_bios_selectors(&args->seg, flags);
435    bioscall_vector.vec16.offset = (u_short)args->entry;
436    bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
437
438    i = bios16_call(&args->r, stack_top);
439
440    if (pte == (u_int *)&PTmap) {
441	*pte = 0;			/* remove entry */
442    } else {
443	*ptd = 0;			/* remove page table */
444	free(pte, M_TEMP);		/* ... and free it */
445    }
446
447    /*
448     * XXX only needs to be invlpg(0) but that doesn't work on the 386
449     */
450    invltlb();
451
452    return (i);
453}
454
455/*
456 * PnP BIOS interface; enumerate devices only known to the system
457 * BIOS and save information about them for later use.
458 */
459
460struct pnp_sysdev
461{
462    u_int16_t	size;
463    u_int8_t	handle;
464    u_int32_t	devid;
465    u_int8_t	type[3];
466    u_int16_t	attrib;
467#define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
468#define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
469#define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
470#define PNPATTR_INPUT		(1<<3)	/* can be primary input */
471#define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
472#define PNPATTR_DOCK		(1<<5)	/* is a docking station */
473#define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
474#define PNPATTR_CONFIG_STATIC	0x00
475#define PNPATTR_CONFIG_DYNAMIC	0x07
476#define PNPATTR_CONFIG_DYNONLY	0x17
477    /* device-specific data comes here */
478    u_int8_t	devdata[0];
479} __attribute__ ((packed));
480
481/* We have to cluster arguments within a 64k range for the bios16 call */
482struct pnp_sysdevargs
483{
484    u_int16_t	next;
485    struct pnp_sysdev node;
486};
487
488/*
489 * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
490 */
491static void
492pnpbios_scan(void)
493{
494    struct PnPBIOS_table	*pt = PnPBIOStable;
495    struct bios_args		args;
496    struct pnp_sysdev		*pd;
497    struct pnp_sysdevargs	*pda;
498    u_int16_t			ndevs, bigdev;
499    int				error, currdev;
500    u_int8_t			*devnodebuf, tag;
501    u_int32_t			*devid, *compid;
502    int				idx, left;
503
504    /* no PnP BIOS information */
505    if (pt == NULL)
506	return;
507
508    bzero(&args, sizeof(args));
509    args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
510    args.seg.code16.limit = 0xffff;		/* XXX ? */
511    args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
512    args.seg.data.limit = 0xffff;
513    args.entry = pt->pmentryoffset;
514
515    if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff))
516	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
517    if (bootverbose)
518	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
519
520    devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
521			M_DEVBUF, M_NOWAIT);
522    pda = (struct pnp_sysdevargs *)devnodebuf;
523    pd = &pda->node;
524
525    for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
526
527	bzero(pd, bigdev);
528	pda->next = currdev;
529	/* get current configuration */
530	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, (u_int16_t)1))) {
531	    printf("pnpbios: error %d making BIOS16 call\n", error);
532	    break;
533	}
534	if ((error = (args.r.eax & 0xff))) {
535	    if (bootverbose)
536		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
537	    if (error & 0x80)
538		break;
539	}
540	currdev = pda->next;
541	if (pd->size < sizeof(struct pnp_sysdev)) {
542	    printf("pnpbios: bogus system node data, aborting scan\n");
543	    break;
544	}
545
546	/* Find device IDs */
547	devid = &pd->devid;
548	compid = NULL;
549
550	/* look for a compatible device ID too */
551	left = pd->size - sizeof(struct pnp_sysdev);
552	idx = 0;
553	while (idx < left) {
554	    tag = pd->devdata[idx++];
555	    if (PNP_RES_TYPE(tag) == 0) {
556		/* Small resource */
557		switch (PNP_SRES_NUM(tag)) {
558		case COMP_DEVICE_ID:
559		    compid = (u_int32_t *)(pd->devdata + idx);
560		    if (bootverbose)
561			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
562		    /* FALLTHROUGH */
563		case END_TAG:
564		    idx = left;
565		    break;
566		default:
567		    idx += PNP_SRES_LEN(tag);
568		    break;
569		}
570	    } else
571		/* Large resource, skip it */
572		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
573	}
574	if (bootverbose) {
575	    printf("pnpbios: handle %d device ID %s (%08x)",
576		   pd->handle, pnp_eisaformat((u_int8_t *)devid), *devid);
577	    if (compid != NULL)
578		printf(" compat ID %s (%08x)",
579		       pnp_eisaformat((u_int8_t *)compid), *compid);
580	    printf("\n");
581	}
582    }
583}
584
585/* XXX should be somewhere else */
586static char *
587pnp_eisaformat(u_int8_t *data)
588{
589    static char idbuf[8];
590    const char  hextoascii[] = "0123456789abcdef";
591
592    idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
593    idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
594    idbuf[2] = '@' + (data[1] & 0x1f);
595    idbuf[3] = hextoascii[(data[2] >> 4)];
596    idbuf[4] = hextoascii[(data[2] & 0xf)];
597    idbuf[5] = hextoascii[(data[3] >> 4)];
598    idbuf[6] = hextoascii[(data[3] & 0xf)];
599    idbuf[7] = 0;
600    return(idbuf);
601}
602