FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/bios.c
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 * $FreeBSD$
28 */
29
30 /*
31 * Code for dealing with the BIOS in x86 PC systems.
32 */
33
34 #include "opt_pnp.h"
35
36 #include "isa.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/bus.h>
43 #include <vm/vm.h>
44 #include <vm/pmap.h>
45 #include <machine/md_var.h>
46 #include <machine/segments.h>
47 #include <machine/stdarg.h>
48 #include <machine/vmparam.h>
49 #include <machine/pc/bios.h>
50 #include <isa/pnpreg.h>
51 #include <isa/pnpvar.h>
52 #if NISA > 0
53 #include <isa/isavar.h>
54 #endif
55
56 #define BIOS_START 0xe0000
57 #define BIOS_SIZE 0x20000
58
59 /* exported lookup results */
60 struct bios32_SDentry PCIbios = {entry : 0};
61 struct PnPBIOS_table *PnPBIOStable = 0;
62
63 static u_int bios32_SDCI = 0;
64
65 /* start fairly early */
66 static void bios32_init(void *junk);
67 SYSINIT(bios32, SI_SUB_CPU, SI_ORDER_ANY, bios32_init, NULL);
68
69 /*
70 * bios32_init
71 *
72 * Locate various bios32 entities.
73 */
74 static void
75 bios32_init(void *junk)
76 {
77 u_long sigaddr;
78 struct bios32_SDheader *sdh;
79 struct PnPBIOS_table *pt;
80 u_int8_t ck, *cv;
81 int i;
82
83 /*
84 * BIOS32 Service Directory
85 */
86
87 /* look for the signature */
88 if ((sigaddr = bios_sigsearch(0, "_32_", 4, 16, 0)) != 0) {
89
90 /* get a virtual pointer to the structure */
91 sdh = (struct bios32_SDheader *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
92 for (cv = (u_int8_t *)sdh, ck = 0, i = 0; i < (sdh->len * 16); i++) {
93 ck += cv[i];
94 }
95 /* If checksum is OK, enable use of the entrypoint */
96 if ((ck == 0) && (sdh->entry < (BIOS_START + BIOS_SIZE))) {
97 bios32_SDCI = BIOS_PADDRTOVADDR(sdh->entry);
98 if (bootverbose) {
99 printf("bios32: Found BIOS32 Service Directory header at %p\n", sdh);
100 printf("bios32: Entry = 0x%x (%x) Rev = %d Len = %d\n",
101 sdh->entry, bios32_SDCI, sdh->revision, sdh->len);
102 }
103 /* See if there's a PCI BIOS entrypoint here */
104 PCIbios.ident.id = 0x49435024; /* PCI systems should have this */
105 if (!bios32_SDlookup(&PCIbios) && bootverbose)
106 printf("pcibios: PCI BIOS entry at 0x%x\n", PCIbios.entry);
107 } else {
108 printf("bios32: Bad BIOS32 Service Directory\n");
109 }
110 }
111
112 /*
113 * PnP BIOS
114 */
115 if ((sigaddr = bios_sigsearch(0, "$PnP", 4, 16, 0)) != 0) {
116
117 /* get a virtual pointer to the structure */
118 pt = (struct PnPBIOS_table *)(uintptr_t)BIOS_PADDRTOVADDR(sigaddr);
119 for (cv = (u_int8_t *)pt, ck = 0, i = 0; i < pt->len; i++) {
120 ck += cv[i];
121 }
122 /* If checksum is OK, enable use of the entrypoint */
123 if (ck == 0) {
124 PnPBIOStable = pt;
125 if (bootverbose) {
126 printf("pnpbios: Found PnP BIOS data at %p\n", pt);
127 printf("pnpbios: Entry = %x:%x Rev = %d.%d\n",
128 pt->pmentrybase, pt->pmentryoffset, pt->version >> 4, pt->version & 0xf);
129 if ((pt->control & 0x3) == 0x01)
130 printf("pnpbios: Event flag at %x\n", pt->evflagaddr);
131 if (pt->oemdevid != 0)
132 printf("pnpbios: OEM ID %x\n", pt->oemdevid);
133
134 }
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, "RSD 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 */
154 int
155 bios32_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 ent->ventry = BIOS_PADDRTOVADDR(ent->base + ent->entry);
170 return (0); /* all OK */
171 }
172 return (1); /* failed */
173 }
174
175
176 /*
177 * bios_sigsearch
178 *
179 * Search some or all of the BIOS region for a signature string.
180 *
181 * (start) Optional offset returned from this function
182 * (for searching for multiple matches), or NULL
183 * to start the search from the base of the BIOS.
184 * Note that this will be a _physical_ address in
185 * the range 0xe0000 - 0xfffff.
186 * (sig) is a pointer to the byte(s) of the signature.
187 * (siglen) number of bytes in the signature.
188 * (paralen) signature paragraph (alignment) size.
189 * (sigofs) offset of the signature within the paragraph.
190 *
191 * Returns the _physical_ address of the found signature, 0 if the
192 * signature was not found.
193 */
194
195 u_int32_t
196 bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
197 {
198 u_char *sp, *end;
199
200 /* compute the starting address */
201 if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
202 sp = (char *)BIOS_PADDRTOVADDR(start);
203 } else if (start == 0) {
204 sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
205 } else {
206 return 0; /* bogus start address */
207 }
208
209 /* compute the end address */
210 end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
211
212 /* loop searching */
213 while ((sp + sigofs + siglen) < end) {
214
215 /* compare here */
216 if (!bcmp(sp + sigofs, sig, siglen)) {
217 /* convert back to physical address */
218 return((u_int32_t)BIOS_VADDRTOPADDR(sp));
219 }
220 sp += paralen;
221 }
222 return(0);
223 }
224
225 /*
226 * do not staticize, used by bioscall.s
227 */
228 union {
229 struct {
230 u_short offset;
231 u_short segment;
232 } vec16;
233 struct {
234 u_int offset;
235 u_short segment;
236 } vec32;
237 } bioscall_vector; /* bios jump vector */
238
239 void
240 set_bios_selectors(struct bios_segments *seg, int flags)
241 {
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 union descriptor *p_gdt;
253
254 #ifdef SMP
255 p_gdt = &gdt[cpuid * NGDT];
256 #else
257 p_gdt = gdt;
258 #endif
259
260 ssd.ssd_base = seg->code32.base;
261 ssd.ssd_limit = seg->code32.limit;
262 ssdtosd(&ssd, &p_gdt[GBIOSCODE32_SEL].sd);
263
264 ssd.ssd_def32 = 0;
265 if (flags & BIOSCODE_FLAG) {
266 ssd.ssd_base = seg->code16.base;
267 ssd.ssd_limit = seg->code16.limit;
268 ssdtosd(&ssd, &p_gdt[GBIOSCODE16_SEL].sd);
269 }
270
271 ssd.ssd_type = SDT_MEMRWA;
272 if (flags & BIOSDATA_FLAG) {
273 ssd.ssd_base = seg->data.base;
274 ssd.ssd_limit = seg->data.limit;
275 ssdtosd(&ssd, &p_gdt[GBIOSDATA_SEL].sd);
276 }
277
278 if (flags & BIOSUTIL_FLAG) {
279 ssd.ssd_base = seg->util.base;
280 ssd.ssd_limit = seg->util.limit;
281 ssdtosd(&ssd, &p_gdt[GBIOSUTIL_SEL].sd);
282 }
283
284 if (flags & BIOSARGS_FLAG) {
285 ssd.ssd_base = seg->args.base;
286 ssd.ssd_limit = seg->args.limit;
287 ssdtosd(&ssd, &p_gdt[GBIOSARGS_SEL].sd);
288 }
289 }
290
291 extern int vm86pa;
292 extern void bios16_jmp(void);
293
294 /*
295 * this routine is really greedy with selectors, and uses 5:
296 *
297 * 32-bit code selector: to return to kernel
298 * 16-bit code selector: for running code
299 * data selector: for 16-bit data
300 * util selector: extra utility selector
301 * args selector: to handle pointers
302 *
303 * the util selector is set from the util16 entry in bios16_args, if a
304 * "U" specifier is seen.
305 *
306 * See <machine/pc/bios.h> for description of format specifiers
307 */
308 int
309 bios16(struct bios_args *args, char *fmt, ...)
310 {
311 char *p, *stack, *stack_top;
312 va_list ap;
313 int flags = BIOSCODE_FLAG | BIOSDATA_FLAG;
314 u_int i, arg_start, arg_end;
315 pt_entry_t *pte;
316 pd_entry_t *ptd;
317
318 arg_start = 0xffffffff;
319 arg_end = 0;
320
321 /*
322 * Some BIOS entrypoints attempt to copy the largest-case
323 * argument frame (in order to generalise handling for
324 * different entry types). If our argument frame is
325 * smaller than this, the BIOS will reach off the top of
326 * our constructed stack segment. Pad the top of the stack
327 * with some garbage to avoid this.
328 */
329 stack = (caddr_t)PAGE_SIZE - 32;
330
331 va_start(ap, fmt);
332 for (p = fmt; p && *p; p++) {
333 switch (*p) {
334 case 'p': /* 32-bit pointer */
335 i = va_arg(ap, u_int);
336 arg_start = min(arg_start, i);
337 arg_end = max(arg_end, i);
338 flags |= BIOSARGS_FLAG;
339 stack -= 4;
340 break;
341
342 case 'i': /* 32-bit integer */
343 i = va_arg(ap, u_int);
344 stack -= 4;
345 break;
346
347 case 'U': /* 16-bit selector */
348 flags |= BIOSUTIL_FLAG;
349 /* FALLTHROUGH */
350 case 'D': /* 16-bit selector */
351 case 'C': /* 16-bit selector */
352 stack -= 2;
353 break;
354
355 case 's': /* 16-bit integer */
356 i = va_arg(ap, u_short);
357 stack -= 2;
358 break;
359
360 default:
361 return (EINVAL);
362 }
363 }
364
365 if (flags & BIOSARGS_FLAG) {
366 if (arg_end - arg_start > ctob(16))
367 return (EACCES);
368 args->seg.args.base = arg_start;
369 args->seg.args.limit = 0xffff;
370 }
371
372 args->seg.code32.base = (u_int)&bios16_jmp & PG_FRAME;
373 args->seg.code32.limit = 0xffff;
374
375 ptd = (pd_entry_t *)rcr3();
376 #ifdef PAE
377 ptd = (pd_entry_t *)(*ptd & PG_FRAME);
378 #endif
379 if (ptd == IdlePTD) {
380 /*
381 * no page table, so create one and install it.
382 */
383 pte = (pt_entry_t *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
384 ptd = (pd_entry_t *)(KERNBASE + IdlePTD);
385 *ptd = vtophys(pte) | PG_RW | PG_V;
386 } else {
387 /*
388 * this is a user-level page table
389 */
390 pte = PTmap;
391 }
392 /*
393 * install pointer to page 0. we don't need to flush the tlb,
394 * since there should not be a previous mapping for page 0.
395 */
396 *pte = (vm86pa - PAGE_SIZE) | PG_RW | PG_V;
397
398 stack_top = stack;
399 va_start(ap, fmt);
400 for (p = fmt; p && *p; p++) {
401 switch (*p) {
402 case 'p': /* 32-bit pointer */
403 i = va_arg(ap, u_int);
404 *(u_int *)stack = (i - arg_start) |
405 (GSEL(GBIOSARGS_SEL, SEL_KPL) << 16);
406 stack += 4;
407 break;
408
409 case 'i': /* 32-bit integer */
410 i = va_arg(ap, u_int);
411 *(u_int *)stack = i;
412 stack += 4;
413 break;
414
415 case 'U': /* 16-bit selector */
416 *(u_short *)stack = GSEL(GBIOSUTIL_SEL, SEL_KPL);
417 stack += 2;
418 break;
419
420 case 'D': /* 16-bit selector */
421 *(u_short *)stack = GSEL(GBIOSDATA_SEL, SEL_KPL);
422 stack += 2;
423 break;
424
425 case 'C': /* 16-bit selector */
426 *(u_short *)stack = GSEL(GBIOSCODE16_SEL, SEL_KPL);
427 stack += 2;
428 break;
429
430 case 's': /* 16-bit integer */
431 i = va_arg(ap, u_short);
432 *(u_short *)stack = i;
433 stack += 2;
434 break;
435
436 default:
437 return (EINVAL);
438 }
439 }
440
441 set_bios_selectors(&args->seg, flags);
442 bioscall_vector.vec16.offset = (u_short)args->entry;
443 bioscall_vector.vec16.segment = GSEL(GBIOSCODE16_SEL, SEL_KPL);
444
445 i = bios16_call(&args->r, stack_top);
446
447 if (pte == PTmap) {
448 *pte = 0; /* remove entry */
449 } else {
450 *ptd = 0; /* remove page table */
451 free(pte, M_TEMP); /* ... and free it */
452 }
453
454 /*
455 * XXX only needs to be invlpg(0) but that doesn't work on the 386
456 */
457 invltlb();
458
459 return (i);
460 }
461
462 #ifdef PNPBIOS /* remove conditional later */
463
464 /*
465 * PnP BIOS interface; enumerate devices only known to the system
466 * BIOS and save information about them for later use.
467 */
468
469 struct pnp_sysdev
470 {
471 u_int16_t size;
472 u_int8_t handle;
473 u_int32_t devid;
474 u_int8_t type[3];
475 u_int16_t attrib;
476 #define PNPATTR_NODISABLE (1<<0) /* can't be disabled */
477 #define PNPATTR_NOCONFIG (1<<1) /* can't be configured */
478 #define PNPATTR_OUTPUT (1<<2) /* can be primary output */
479 #define PNPATTR_INPUT (1<<3) /* can be primary input */
480 #define PNPATTR_BOOTABLE (1<<4) /* can be booted from */
481 #define PNPATTR_DOCK (1<<5) /* is a docking station */
482 #define PNPATTR_REMOVEABLE (1<<6) /* device is removeable */
483 #define PNPATTR_CONFIG_STATIC 0x00
484 #define PNPATTR_CONFIG_DYNAMIC 0x07
485 #define PNPATTR_CONFIG_DYNONLY 0x17
486 /* device-specific data comes here */
487 u_int8_t devdata[0];
488 } __attribute__ ((packed));
489
490 /* We have to cluster arguments within a 64k range for the bios16 call */
491 struct pnp_sysdevargs
492 {
493 u_int16_t next;
494 struct pnp_sysdev node;
495 };
496
497 /*
498 * This function is called after the bus has assigned resource
499 * locations for a logical device.
500 */
501 static void
502 pnpbios_set_config(void *arg, struct isa_config *config, int enable)
503 {
504 }
505
506 /*
507 * Quiz the PnP BIOS, build a list of PNP IDs and resource data.
508 */
509 static void
510 pnpbios_identify(driver_t *driver, device_t parent)
511 {
512 struct PnPBIOS_table *pt = PnPBIOStable;
513 struct bios_args args;
514 struct pnp_sysdev *pd;
515 struct pnp_sysdevargs *pda;
516 u_int16_t ndevs, bigdev;
517 int error, currdev;
518 u_int8_t *devnodebuf, tag;
519 u_int32_t *devid, *compid;
520 int idx, left;
521 device_t dev;
522
523 /* no PnP BIOS information */
524 if (pt == NULL)
525 return;
526
527 bzero(&args, sizeof(args));
528 args.seg.code16.base = BIOS_PADDRTOVADDR(pt->pmentrybase);
529 args.seg.code16.limit = 0xffff; /* XXX ? */
530 args.seg.data.base = BIOS_PADDRTOVADDR(pt->pmdataseg);
531 args.seg.data.limit = 0xffff;
532 args.entry = pt->pmentryoffset;
533
534 if ((error = bios16(&args, PNP_COUNT_DEVNODES, &ndevs, &bigdev)) || (args.r.eax & 0xff))
535 printf("pnpbios: error %d/%x getting device count/size limit\n", error, args.r.eax);
536 ndevs &= 0xff; /* clear high byte garbage */
537 if (bootverbose)
538 printf("pnpbios: %d devices, largest %d bytes\n", ndevs, bigdev);
539
540 devnodebuf = malloc(bigdev + (sizeof(struct pnp_sysdevargs) - sizeof(struct pnp_sysdev)),
541 M_DEVBUF, M_NOWAIT);
542 pda = (struct pnp_sysdevargs *)devnodebuf;
543 pd = &pda->node;
544
545 for (currdev = 0, left = ndevs; (currdev != 0xff) && (left > 0); left--) {
546
547 bzero(pd, bigdev);
548 pda->next = currdev;
549 /* get current configuration */
550 if ((error = bios16(&args, PNP_GET_DEVNODE, &pda->next, &pda->node, (u_int16_t)1))) {
551 printf("pnpbios: error %d making BIOS16 call\n", error);
552 break;
553 }
554 if ((error = (args.r.eax & 0xff))) {
555 if (bootverbose)
556 printf("pnpbios: %s 0x%x fetching node %d\n", error & 0x80 ? "error" : "warning", error, currdev);
557 if (error & 0x80)
558 break;
559 }
560 currdev = pda->next;
561 if (pd->size < sizeof(struct pnp_sysdev)) {
562 printf("pnpbios: bogus system node data, aborting scan\n");
563 break;
564 }
565
566 /*
567 * If we are in APIC_IO mode, we should ignore the ISA PIC if it
568 * shows up. Likewise, in !APIC_IO mode, we should ignore the
569 * APIC (less important).
570 * This is significant because the ISA PIC will claim IRQ 2 (which
571 * it uses for chaining), while in APIC mode this is a valid IRQ
572 * available for general use.
573 */
574 #ifdef APIC_IO
575 if (!strcmp(pnp_eisaformat(pd->devid), "PNP0000")) /* ISA PIC */
576 continue;
577 #else
578 if (!strcmp(pnp_eisaformat(pd->devid), "PNP0003")) /* APIC */
579 continue;
580 #endif
581
582 /* Add the device and parse its resources */
583 dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
584 isa_set_vendorid(dev, pd->devid);
585 isa_set_logicalid(dev, pd->devid);
586 ISA_SET_CONFIG_CALLBACK(parent, dev, pnpbios_set_config, 0);
587 pnp_parse_resources(dev, &pd->devdata[0],
588 pd->size - sizeof(struct pnp_sysdev));
589 if (!device_get_desc(dev))
590 device_set_desc_copy(dev, pnp_eisaformat(pd->devid));
591
592 /* Find device IDs */
593 devid = &pd->devid;
594 compid = NULL;
595
596 /* look for a compatible device ID too */
597 left = pd->size - sizeof(struct pnp_sysdev);
598 idx = 0;
599 while (idx < left) {
600 tag = pd->devdata[idx++];
601 if (PNP_RES_TYPE(tag) == 0) {
602 /* Small resource */
603 switch (PNP_SRES_NUM(tag)) {
604 case PNP_TAG_COMPAT_DEVICE:
605 compid = (u_int32_t *)(pd->devdata + idx);
606 if (bootverbose)
607 printf("pnpbios: node %d compat ID 0x%08x\n", pd->handle, *compid);
608 /* FALLTHROUGH */
609 case PNP_TAG_END:
610 idx = left;
611 break;
612 default:
613 idx += PNP_SRES_LEN(tag);
614 break;
615 }
616 } else
617 /* Large resource, skip it */
618 idx += *(u_int16_t *)(pd->devdata + idx) + 2;
619 }
620 if (bootverbose) {
621 printf("pnpbios: handle %d device ID %s (%08x)",
622 pd->handle, pnp_eisaformat(*devid), *devid);
623 if (compid != NULL)
624 printf(" compat ID %s (%08x)",
625 pnp_eisaformat(*compid), *compid);
626 printf("\n");
627 }
628 }
629 }
630
631 static device_method_t pnpbios_methods[] = {
632 /* Device interface */
633 DEVMETHOD(device_identify, pnpbios_identify),
634
635 { 0, 0 }
636 };
637
638 static driver_t pnpbios_driver = {
639 "pnpbios",
640 pnpbios_methods,
641 1, /* no softc */
642 };
643
644 static devclass_t pnpbios_devclass;
645
646 DRIVER_MODULE(pnpbios, isa, pnpbios_driver, pnpbios_devclass, 0, 0);
647
648 #endif /* PNPBIOS */
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