bios.c revision 51121 
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 51121 1999-09-10 08:49:19Z msmith $
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 <isa/pnpreg.h>
48
49#define BIOS_START	0xe0000
50#define BIOS_SIZE	0x20000
51
52/* exported lookup results */
53struct bios32_SDentry		PCIbios = {entry : 0};
54struct PnPBIOS_table		*PnPBIOStable = 0;
55
56static u_int			bios32_SDCI = 0;
57
58/* start fairly early */
59static void			bios32_init(void *junk);
60SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
61
62static void	pnpbios_scan(void);
63static char 	*pnp_eisaformat(u_int8_t *data);
64
65
66/*
67 * bios32_init
68 *
69 * Locate various bios32 entities.
70 */
71static void
72bios32_init(void *junk)
73{
74    u_long			sigaddr;
75    struct bios32_SDheader	*sdh;
76    struct PnPBIOS_table	*pt;
77    u_int8_t			ck, *cv;
78    int				i;
79
80    /*
81     * BIOS32 Service Directory
82     */
83
84    /* look for the signature */
85    if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
86
87	/* get a virtual pointer to the structure */
88	sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
89	for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
90	    ck += cv[i];
91	}
92	/* If checksum is OK, enable use of the entrypoint */
93	if ((ck == 0) && (sdh->entry < (BIOS_START + BIOS_SIZE))) {
94	    bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
95	    if (bootverbose) {
96		printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
97		printf("bios32: Entry = 0x%x (%x)  Rev = %d  Len = %d\n",
98		       sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
99	    }
100	    /* See if there's a PCI BIOS entrypoint here */
101	    PCIbios.ident.id = 0x49435024;	/* PCI systems should have this */
102	    if (!bios32_SDlookup(&PCIbios) && bootverbose)
103		printf("pcibios: PCI BIOS entry at 0x%x\n", PCIbios.entry);
104	} else {
105	    printf("bios32: Bad BIOS32 Service Directory\n");
106	}
107    }
108
109    /*
110     * PnP BIOS
111     */
112    if ((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0) {
113
114	/* get a virtual pointer to the structure */
115	pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
116	for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
117	    ck += cv[i];
118	}
119	/* If checksum is OK, enable use of the entrypoint */
120	if (ck == 0) {
121	    PnPBIOStable = pt;
122	    if (bootverbose) {
123		printf("pnpbios: Found PnP BIOS data at %p\n", pt);
124		printf("pnpbios: Entry = %x:%x  Rev = %d.%d\n",
125		       pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
126		if ((pt->control & 0x3) == 0x01)
127		    printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
128		if (pt->oemdevid != 0)
129		    printf("pnpbios: OEM ID %x\n", pt->oemdevid);
130
131	    }
132	    pnpbios_scan();
133	} else {
134	    printf("pnpbios: Bad PnP BIOS data checksum\n");
135	}
136    }
137
138    if (bootverbose) {
139	    /* look for other know signatures */
140	    printf("Other BIOS signatures found:\n");
141	    printf("ACPI: %08x\n", bios_sigsearch(0, "RSD PTR ", 8, 16, 0));
142    }
143}
144
145/*
146 * bios32_SDlookup
147 *
148 * Query the BIOS32 Service Directory for the service named in (ent),
149 * returns nonzero if the lookup fails.  The caller must fill in
150 * (ent->ident), the remainder are populated on a successful lookup.
151 */
152int
153bios32_SDlookup(struct bios32_SDentry *ent)
154{
155    struct bios_regs args;
156
157    if (bios32_SDCI == 0)
158	return (1);
159
160    args.eax = ent->ident.id;		/* set up arguments */
161    args.ebx = args.ecx = args.edx = 0;
162    bios32(&args, bios32_SDCI, GSEL(GCODE_SEL, SEL_KPL));
163    if ((args.eax & 0xff) == 0) {	/* success? */
164	ent->base = args.ebx;
165	ent->len = args.ecx;
166	ent->entry = args.edx;
167	return (0);			/* all OK */
168    }
169    return (1);				/* failed */
170}
171
172
173/*
174 * bios_sigsearch
175 *
176 * Search some or all of the BIOS region for a signature string.
177 *
178 * (start)	Optional offset returned from this function
179 *		(for searching for multiple matches), or NULL
180 *		to start the search from the base of the BIOS.
181 *		Note that this will be a _physical_ address in
182 *		the range 0xe0000 - 0xfffff.
183 * (sig)	is a pointer to the byte(s) of the signature.
184 * (siglen)	number of bytes in the signature.
185 * (paralen)	signature paragraph (alignment) size.
186 * (sigofs)	offset of the signature within the paragraph.
187 *
188 * Returns the _physical_ address of the found signature, 0 if the
189 * signature was not found.
190 */
191
192u_int32_t
193bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
194{
195    u_char	*sp, *end;
196
197    /* compute the starting address */
198    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
199	sp = (char *)BIOS_PADDRTOVADDR(start);
200    } else if (start == 0) {
201	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
202    } else {
203	return 0;				/* bogus start address */
204    }
205
206    /* compute the end address */
207    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
208
209    /* loop searching */
210    while ((sp + sigofs + siglen) < end) {
211
212	/* compare here */
213	if (!bcmp(sp + sigofs, sig, siglen)) {
214	    /* convert back to physical address */
215	    return((u_int32_t)BIOS_VADDRTOPADDR(sp));
216	}
217	sp += paralen;
218    }
219    return(0);
220}
221
222/*
223 * do not staticize, used by bioscall.s
224 */
225union {
226    struct {
227	u_short	offset;
228	u_short	segment;
229    } vec16;
230    struct {
231	u_int	offset;
232	u_short	segment;
233    } vec32;
234} bioscall_vector;			/* bios jump vector */
235
236void
237set_bios_selectors(struct bios_segments *seg, int flags)
238{
239    struct soft_segment_descriptor ssd = {
240	0,			/* segment base address (overwritten) */
241	0,			/* length (overwritten) */
242	SDT_MEMERA,		/* segment type (overwritten) */
243	0,			/* priority level */
244	1,			/* descriptor present */
245	0, 0,
246	1,			/* descriptor size (overwritten) */
247	0			/* granularity == byte units */
248    };
249    union descriptor *p_gdt;
250
251#ifdef SMP
252    p_gdt = &gdt[cpuid];
253#else
254    p_gdt = gdt;
255#endif
256
257    ssd.ssd_base = seg->code32.base;
258    ssd.ssd_limit = seg->code32.limit;
259    ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
260
261    ssd.ssd_def32 = 0;
262    if (flags & BIOSCODE_FLAG) {
263	ssd.ssd_base = seg->code16.base;
264	ssd.ssd_limit = seg->code16.limit;
265	ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
266    }
267
268    ssd.ssd_type = SDT_MEMRWA;
269    if (flags & BIOSDATA_FLAG) {
270	ssd.ssd_base = seg->data.base;
271	ssd.ssd_limit = seg->data.limit;
272	ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
273    }
274
275    if (flags & BIOSUTIL_FLAG) {
276	ssd.ssd_base = seg->util.base;
277	ssd.ssd_limit = seg->util.limit;
278	ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
279    }
280
281    if (flags & BIOSARGS_FLAG) {
282	ssd.ssd_base = seg->args.base;
283	ssd.ssd_limit = seg->args.limit;
284	ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
285    }
286}
287
288extern int vm86pa;
289extern void bios16_jmp(void);
290
291/*
292 * this routine is really greedy with selectors, and uses 5:
293 *
294 * 32-bit code selector:	to return to kernel
295 * 16-bit code selector:	for running code
296 *        data selector:	for 16-bit data
297 *        util selector:	extra utility selector
298 *        args selector:	to handle pointers
299 *
300 * the util selector is set from the util16 entry in bios16_args, if a
301 * "U" specifier is seen.
302 *
303 * See <machine/pc/bios.h> for description of format specifiers
304 */
305int
306bios16(struct bios_args *args, char *fmt, ...)
307{
308    char	*p, *stack, *stack_top;
309    va_list 	ap;
310    int 	flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
311    u_int 	i, arg_start, arg_end;
312    u_int 	*pte, *ptd;
313
314    arg_start = 0xffffffff;
315    arg_end = 0;
316
317    /*
318     * Some BIOS entrypoints attempt to copy the largest-case
319     * argument frame (in order to generalise handling for
320     * different entry types).  If our argument frame is
321     * smaller than this, the BIOS will reach off the top of
322     * our constructed stack segment.  Pad the top of the stack
323     * with some garbage to avoid this.
324     */
325    stack = (caddr_t)PAGE_SIZE - 32;
326
327    va_start(ap, fmt);
328    for (p = fmt; p && *p; p++) {
329	switch (*p) {
330	case 'p':			/* 32-bit pointer */
331	    i = va_arg(ap, u_int);
332	    arg_start = min(arg_start, i);
333	    arg_end = max(arg_end, i);
334	    flags |= BIOSARGS_FLAG;
335	    stack -= 4;
336	    break;
337
338	case 'i':			/* 32-bit integer */
339	    i = va_arg(ap, u_int);
340	    stack -= 4;
341	    break;
342
343	case 'U':			/* 16-bit selector */
344	    flags |= BIOSUTIL_FLAG;
345	    /* FALLTHROUGH */
346	case 'D':			/* 16-bit selector */
347	case 'C':			/* 16-bit selector */
348	    stack -= 2;
349	    break;
350
351	case 's':			/* 16-bit integer */
352	    i = va_arg(ap, u_short);
353	    stack -= 2;
354	    break;
355
356	default:
357	    return (EINVAL);
358	}
359    }
360
361    if (flags & BIOSARGS_FLAG) {
362	if (arg_end - arg_start > ctob(16))
363	    return (EACCES);
364	args->seg.args.base = arg_start;
365	args->seg.args.limit = 0xffff;
366    }
367
368    args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
369    args->seg.code32.limit = 0xffff;
370
371    ptd = (u_int *)rcr3();
372    if (ptd == IdlePTD) {
373	/*
374	 * no page table, so create one and install it.
375	 */
376	pte = (u_int *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
377	ptd = (u_int *)((u_int)ptd + KERNBASE);
378	*ptd = vtophys(pte) | PG_RW | PG_V;
379    } else {
380	/*
381	 * this is a user-level page table
382	 */
383	pte = (u_int *)&PTmap;
384    }
385    /*
386     * install pointer to page 0.  we don't need to flush the tlb,
387     * since there should not be a previous mapping for page 0.
388     */
389    *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
390
391    stack_top = stack;
392    va_start(ap, fmt);
393    for (p = fmt; p && *p; p++) {
394	switch (*p) {
395	case 'p':			/* 32-bit pointer */
396	    i = va_arg(ap, u_int);
397	    *(u_int *)stack = (i - arg_start) |
398		(GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
399	    stack += 4;
400	    break;
401
402	case 'i':			/* 32-bit integer */
403	    i = va_arg(ap, u_int);
404	    *(u_int *)stack = i;
405	    stack += 4;
406	    break;
407
408	case 'U':			/* 16-bit selector */
409	    *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
410	    stack += 2;
411	    break;
412
413	case 'D':			/* 16-bit selector */
414	    *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
415	    stack += 2;
416	    break;
417
418	case 'C':			/* 16-bit selector */
419	    *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
420	    stack += 2;
421	    break;
422
423	case 's':			/* 16-bit integer */
424	    i = va_arg(ap, u_short);
425	    *(u_short *)stack = i;
426	    stack += 2;
427	    break;
428
429	default:
430	    return (EINVAL);
431	}
432    }
433
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 PNP_TAG_COMPAT_DEVICE:
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 PNP_TAG_END:
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