bios.c revision 50337 
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 1.20 1999/08/25 06:44:32 peter 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     * BIOS32 Service Directory
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	    /* See if there's a PCI BIOS entrypoint here */
102	    PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
103	    if (!bios32_SDlookup(&PCIbios) && bootverbose)
104		printf("pcibios: PCI BIOS entry at 0x%x\n", PCIbios.entry);
105	} else {
106	    printf("bios32: Bad BIOS32 Service Directory\n");
107	}
108    }
109
110    /*
111     * PnP BIOS
112     */
113    if ((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0) {
114
115	/* get a virtual pointer to the structure */
116	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
117	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
118	    ck += cv[i];
119	}
120	/* If checksum is OK, enable use of the entrypoint */
121	if (ck == 0) {
122	    PnPBIOStable = pt;
123	    if (bootverbose) {
124		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
125		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
126		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
127		if ((pt->control & 0x3) == 0x01)
128		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
129		if (pt->oemdevid != 0)
130		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
131
132	    }
133	    pnpbios_scan();
134	} else {
135	    printf("pnpbios: Bad PnP BIOS data checksum\n");
136	}
137    }
138
139    if (bootverbose) {
140	    /* look for other know signatures */
141	    printf("Other BIOS signatures found:\n");
142	    printf("ACPI: %08x\n", bios_sigsearch(0, "RST PTR", 8, 16, 0));
143    }
144}
145
146/*
147 * bios32_SDlookup
148 *
149 * Query the BIOS32 Service Directory for the service named in (ent),
150 * returns nonzero if the lookup fails.  The caller must fill in
151 * (ent->ident), the remainder are populated on a successful lookup.
152 */
153int
154bios32_SDlookup(struct bios32_SDentry *ent)
155{
156    struct bios_regs args;
157
158    if (bios32_SDCI == 0)
159	return (1);
160
161    args.eax = ent->ident.id;		/* set up arguments */
162    args.ebx = args.ecx = args.edx = 0;
163    bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
164    if ((args.eax & 0xff) == 0) {	/* success? */
165	ent->base = args.ebx;
166	ent->len = args.ecx;
167	ent->entry = args.edx;
168	return (0);			/* all OK */
169    }
170    return (1);				/* failed */
171}
172
173
174/*
175 * bios_sigsearch
176 *
177 * Search some or all of the BIOS region for a signature string.
178 *
179 * (start)	Optional offset returned from this function
180 *		(for searching for multiple matches), or NULL
181 *		to start the search from the base of the BIOS.
182 *		Note that this will be a _physical_ address in
183 *		the range 0xe0000 - 0xfffff.
184 * (sig)	is a pointer to the byte(s) of the signature.
185 * (siglen)	number of bytes in the signature.
186 * (paralen)	signature paragraph (alignment) size.
187 * (sigofs)	offset of the signature within the paragraph.
188 *
189 * Returns the _physical_ address of the found signature, 0 if the
190 * signature was not found.
191 */
192
193u_int32_t
194bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
195{
196    u_char	*sp, *end;
197
198    /* compute the starting address */
199    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
200	sp = (char *)BIOS_PADDRTOVADDR(start);
201    } else if (start == 0) {
202	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
203    } else {
204	return 0;				/* bogus start address */
205    }
206
207    /* compute the end address */
208    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
209
210    /* loop searching */
211    while ((sp + sigofs + siglen) < end) {
212
213	/* compare here */
214	if (!bcmp(sp + sigofs, sig, siglen)) {
215	    /* convert back to physical address */
216	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
217	}
218	sp += paralen;
219    }
220    return(0);
221}
222
223/*
224 * do not staticize, used by bioscall.s
225 */
226union {
227    struct {
228	u_short	offset;
229	u_short	segment;
230    } vec16;
231    struct {
232	u_int	offset;
233	u_short	segment;
234    } vec32;
235} bioscall_vector;			/* bios jump vector */
236
237void
238set_bios_selectors(struct bios_segments *seg, int flags)
239{
240    static u_int curgen = 1;
241    struct soft_segment_descriptor ssd = {
242	0,			/* segment base address (overwritten) */
243	0,			/* length (overwritten) */
244	SDT_MEMERA,		/* segment type (overwritten) */
245	0,			/* priority level */
246	1,			/* descriptor present */
247	0, 0,
248	1,			/* descriptor size (overwritten) */
249	0			/* granularity == byte units */
250    };
251
252    if (seg->generation == curgen)
253	return;
254    if (++curgen == 0)
255	curgen = 1;
256    seg->generation = curgen;
257
258    ssd.ssd_base = seg->code32.base;
259    ssd.ssd_limit = seg->code32.limit;
260    ssdtosd(&ssd, &gdt[GBIOSCODE32_SEL].sd);
261
262    ssd.ssd_def32 = 0;
263    if (flags & BIOSCODE_FLAG) {
264	ssd.ssd_base = seg->code16.base;
265	ssd.ssd_limit = seg->code16.limit;
266	ssdtosd(&ssd, &gdt[GBIOSCODE16_SEL].sd);
267    }
268
269    ssd.ssd_type = SDT_MEMRWA;
270    if (flags & BIOSDATA_FLAG) {
271	ssd.ssd_base = seg->data.base;
272	ssd.ssd_limit = seg->data.limit;
273	ssdtosd(&ssd, &gdt[GBIOSDATA_SEL].sd);
274    }
275
276    if (flags & BIOSUTIL_FLAG) {
277	ssd.ssd_base = seg->util.base;
278	ssd.ssd_limit = seg->util.limit;
279	ssdtosd(&ssd, &gdt[GBIOSUTIL_SEL].sd);
280    }
281
282    if (flags & BIOSARGS_FLAG) {
283	ssd.ssd_base = seg->args.base;
284	ssd.ssd_limit = seg->args.limit;
285	ssdtosd(&ssd, &gdt[GBIOSARGS_SEL].sd);
286    }
287}
288
289extern int vm86pa;
290extern void bios16_jmp(void);
291
292/*
293 * this routine is really greedy with selectors, and uses 5:
294 *
295 * 32-bit code selector:	to return to kernel
296 * 16-bit code selector:	for running code
297 *        data selector:	for 16-bit data
298 *        util selector:	extra utility selector
299 *        args selector:	to handle pointers
300 *
301 * the util selector is set from the util16 entry in bios16_args, if a
302 * "U" specifier is seen.
303 *
304 * See <machine/pc/bios.h> for description of format specifiers
305 */
306int
307bios16(struct bios_args *args, char *fmt, ...)
308{
309    char	*p, *stack, *stack_top;
310    va_list 	ap;
311    int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
312    u_int 	i, arg_start, arg_end;
313    u_int 	*pte, *ptd;
314
315    arg_start = 0xffffffff;
316    arg_end = 0;
317
318    /*
319     * Some BIOS entrypoints attempt to copy the largest-case
320     * argument frame (in order to generalise handling for
321     * different entry types).  If our argument frame is
322     * smaller than this, the BIOS will reach off the top of
323     * our constructed stack segment.  Pad the top of the stack
324     * with some garbage to avoid this.
325     */
326    stack = (caddr_t)PAGE_SIZE - 32;
327
328    va_start(ap, fmt);
329    for (p = fmt; p && *p; p++) {
330	switch (*p) {
331	case 'p':			/* 32-bit pointer */
332	    i = va_arg(ap, u_int);
333	    arg_start = min(arg_start, i);
334	    arg_end = max(arg_end, i);
335	    flags |= BIOSARGS_FLAG;
336	    stack -= 4;
337	    break;
338
339	case 'i':			/* 32-bit integer */
340	    i = va_arg(ap, u_int);
341	    stack -= 4;
342	    break;
343
344	case 'U':			/* 16-bit selector */
345	    flags |= BIOSUTIL_FLAG;
346	    /* FALLTHROUGH */
347	case 'D':			/* 16-bit selector */
348	case 'C':			/* 16-bit selector */
349	    stack -= 2;
350	    break;
351
352	case 's':			/* 16-bit integer */
353	    i = va_arg(ap, u_short);
354	    stack -= 2;
355	    break;
356
357	default:
358	    return (EINVAL);
359	}
360    }
361
362    if (flags & BIOSARGS_FLAG) {
363	if (arg_end - arg_start > ctob(16))
364	    return (EACCES);
365	args->seg.args.base = arg_start;
366	args->seg.args.limit = 0xffff;
367    }
368
369    args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
370    args->seg.code32.limit = 0xffff;
371
372    ptd = (u_int *)rcr3();
373    if (ptd == IdlePTD) {
374	/*
375	 * no page table, so create one and install it.
376	 */
377	pte = (u_int *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
378	ptd = (u_int *)((u_int)ptd + KERNBASE);
379	*ptd = vtophys(pte) | PG_RW | PG_V;
380    } else {
381	/*
382	 * this is a user-level page table
383	 */
384	pte = (u_int *)&PTmap;
385    }
386    /*
387     * install pointer to page 0.  we don't need to flush the tlb,
388     * since there should not be a previous mapping for page 0.
389     */
390    *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
391
392    stack_top = stack;
393    va_start(ap, fmt);
394    for (p = fmt; p && *p; p++) {
395	switch (*p) {
396	case 'p':			/* 32-bit pointer */
397	    i = va_arg(ap, u_int);
398	    *(u_int *)stack = (i - arg_start) |
399		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
400	    stack += 4;
401	    break;
402
403	case 'i':			/* 32-bit integer */
404	    i = va_arg(ap, u_int);
405	    *(u_int *)stack = i;
406	    stack += 4;
407	    break;
408
409	case 'U':			/* 16-bit selector */
410	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
411	    stack += 2;
412	    break;
413
414	case 'D':			/* 16-bit selector */
415	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
416	    stack += 2;
417	    break;
418
419	case 'C':			/* 16-bit selector */
420	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
421	    stack += 2;
422	    break;
423
424	case 's':			/* 16-bit integer */
425	    i = va_arg(ap, u_short);
426	    *(u_short *)stack = i;
427	    stack += 2;
428	    break;
429
430	default:
431	    return (EINVAL);
432	}
433    }
434
435    args->seg.generation = 0;			/* reload selectors */
436    set_bios_selectors(&args->seg, flags);
437    bioscall_vector.vec16.offset = (u_short)args->entry;
438    bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
439
440    i = bios16_call(&args->r, stack_top);
441
442    if (pte == (u_int *)&PTmap) {
443	*pte = 0;			/* remove entry */
444    } else {
445	*ptd = 0;			/* remove page table */
446	free(pte, M_TEMP);		/* ... and free it */
447    }
448
449    /*
450     * XXX only needs to be invlpg(0) but that doesn't work on the 386
451     */
452    invltlb();
453
454    return (i);
455}
456
457/*
458 * PnP BIOS interface; enumerate devices only known to the system
459 * BIOS and save information about them for later use.
460 */
461
462struct pnp_sysdev
463{
464    u_int16_t	size;
465    u_int8_t	handle;
466    u_int32_t	devid;
467    u_int8_t	type[3];
468    u_int16_t	attrib;
469#define PNPATTR_NODISABLE	(1<<0)	/* can't be disabled */
470#define PNPATTR_NOCONFIG	(1<<1)	/* can't be configured */
471#define PNPATTR_OUTPUT		(1<<2)	/* can be primary output */
472#define PNPATTR_INPUT		(1<<3)	/* can be primary input */
473#define PNPATTR_BOOTABLE	(1<<4)	/* can be booted from */
474#define PNPATTR_DOCK		(1<<5)	/* is a docking station */
475#define PNPATTR_REMOVEABLE	(1<<6)	/* device is removeable */
476#define PNPATTR_CONFIG_STATIC	0x00
477#define PNPATTR_CONFIG_DYNAMIC	0x07
478#define PNPATTR_CONFIG_DYNONLY	0x17
479    /* device-specific data comes here */
480    u_int8_t	devdata[0];
481} __attribute__ ((packed));
482
483/* We have to cluster arguments within a 64k range for the bios16 call */
484struct pnp_sysdevargs
485{
486    u_int16_t	next;
487    struct pnp_sysdev node;
488};
489
490/*
491 * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
492 */
493static void
494pnpbios_scan(void)
495{
496    struct PnPBIOS_table	*pt = PnPBIOStable;
497    struct bios_args		args;
498    struct pnp_sysdev		*pd;
499    struct pnp_sysdevargs	*pda;
500    u_int16_t			ndevs, bigdev;
501    int				error, currdev;
502    u_int8_t			*devnodebuf, tag;
503    u_int32_t			*devid, *compid;
504    int				idx, left;
505
506    /* no PnP BIOS information */
507    if (pt == NULL)
508	return;
509
510    bzero(&args, sizeof(args));
511    args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
512    args.seg.code16.limit = 0xffff;		/* XXX ? */
513    args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
514    args.seg.data.limit = 0xffff;
515    args.entry = pt->pmentryoffset;
516
517    if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff))
518	printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
519    if (bootverbose)
520	printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
521
522    devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
523			M_DEVBUF, M_NOWAIT);
524    pda = (struct pnp_sysdevargs *)devnodebuf;
525    pd = &pda->node;
526
527    for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
528
529	bzero(pd, bigdev);
530	pda->next = currdev;
531	/* get current configuration */
532	if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, (u_int16_t)1))) {
533	    printf("pnpbios: error %d making BIOS16 call\n", error);
534	    break;
535	}
536	if ((error = (args.r.eax & 0xff))) {
537	    if (bootverbose)
538		printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
539	    if (error & 0x80)
540		break;
541	}
542	currdev = pda->next;
543	if (pd->size < sizeof(struct pnp_sysdev)) {
544	    printf("pnpbios: bogus system node data, aborting scan\n");
545	    break;
546	}
547
548	/* Find device IDs */
549	devid = &pd->devid;
550	compid = NULL;
551
552	/* look for a compatible device ID too */
553	left = pd->size - sizeof(struct pnp_sysdev);
554	idx = 0;
555	while (idx < left) {
556	    tag = pd->devdata[idx++];
557	    if (PNP_RES_TYPE(tag) == 0) {
558		/* Small resource */
559		switch (PNP_SRES_NUM(tag)) {
560		case COMP_DEVICE_ID:
561		    compid = (u_int32_t *)(pd->devdata + idx);
562		    if (bootverbose)
563			printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
564		    /* FALLTHROUGH */
565		case END_TAG:
566		    idx = left;
567		    break;
568		default:
569		    idx += PNP_SRES_LEN(tag);
570		    break;
571		}
572	    } else
573		/* Large resource, skip it */
574		idx += *(u_int16_t *)(pd->devdata + idx) + 2;
575	}
576	if (bootverbose) {
577	    printf("pnpbios: handle %d device ID %s (%08x)",
578		   pd->handle, pnp_eisaformat((u_int8_t *)devid), *devid);
579	    if (compid != NULL)
580		printf(" compat ID %s (%08x)",
581		       pnp_eisaformat((u_int8_t *)compid), *compid);
582	    printf("\n");
583	}
584    }
585}
586
587/* XXX should be somewhere else */
588static char *
589pnp_eisaformat(u_int8_t *data)
590{
591    static char idbuf[8];
592    const char  hextoascii[] = "0123456789abcdef";
593
594    idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
595    idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
596    idbuf[2] = '@' + (data[1] & 0x1f);
597    idbuf[3] = hextoascii[(data[2] >> 4)];
598    idbuf[4] = hextoascii[(data[2] & 0xf)];
599    idbuf[5] = hextoascii[(data[3] >> 4)];
600    idbuf[6] = hextoascii[(data[3] & 0xf)];
601    idbuf[7] = 0;
602    return(idbuf);
603}
604