xref: /openbsd/sys/arch/i386/stand/libsa/pciprobe.c (revision d415bd75)
1 /*	$OpenBSD: pciprobe.c,v 1.11 2023/07/24 14:02:36 jsg Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 Tobias Weingartner
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/param.h>
31 #include <stand/boot/bootarg.h>
32 #include <machine/biosvar.h>
33 #include "libsa.h"
34 
35 #define PCI_SIG 0x20494350		/* PCI Signature */
36 
37 void
38 pciprobe(void)
39 {
40 	bios_pciinfo_t bpi;
41 	u_int32_t hw_chars, rev, rc, sig;
42 	u_int32_t entry32, lastbus;
43 
44 	/* PCI BIOS v2.0c+ - Installation Check */
45 	__asm volatile(DOINT(0x1A)
46 		: "=a" (hw_chars), "=b" (rev), "=c" (lastbus),
47 		  "=d" (sig), "=D" (entry32), "=@ccc" (rc)
48 		: "0" (0xB101), "4" (0x0)
49 		: "cc");
50 
51 	if (rc & 0xff || hw_chars & 0xff00)
52 		return;
53 	if (sig != PCI_SIG)
54 		return;
55 
56 	printf(" pci");
57 #ifdef DEBUG
58 	printf("[V%d.%d, %x 0x%x %d]", (rev>>8)&0xFF, (rev&0xFF),
59 		hw_chars, entry32, (rc>>8)&0xFF);
60 #endif
61 
62 	bpi.pci_chars = hw_chars & 0xFFFF;
63 	bpi.pci_rev = rev & 0xFFFF;
64 	bpi.pci_entry32 = entry32;
65 	bpi.pci_lastbus = lastbus & 0xFF;
66 
67 	addbootarg(BOOTARG_PCIINFO, sizeof(bios_pciinfo_t), &bpi);
68 }
69