1 /*-
2 * Copyright (c) 2001 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <stand.h>
31 #include <machine/stdarg.h>
32 #include <bootstrap.h>
33 #include <btxv86.h>
34 #include "libi386.h"
35
36 #include "platform/acfreebsd.h"
37 #include "acconfig.h"
38 #define ACPI_SYSTEM_XFACE
39 #include "actypes.h"
40 #include "actbl.h"
41
42 /*
43 * Detect ACPI and export information about the ACPI BIOS into the
44 * environment.
45 */
46
47 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void);
48 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length);
49
50 #define RSDP_CHECKSUM_LENGTH 20
51
52 void
biosacpi_detect(void)53 biosacpi_detect(void)
54 {
55 ACPI_TABLE_RSDP *rsdp;
56 char buf[24];
57 int revision;
58
59 /* locate and validate the RSDP */
60 if ((rsdp = biosacpi_find_rsdp()) == NULL)
61 return;
62
63 /* export values from the RSDP */
64 sprintf(buf, "0x%08x", VTOP(rsdp));
65 setenv("hint.acpi.0.rsdp", buf, 1);
66 revision = rsdp->Revision;
67 if (revision == 0)
68 revision = 1;
69 sprintf(buf, "%d", revision);
70 setenv("hint.acpi.0.revision", buf, 1);
71 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId));
72 buf[sizeof(rsdp->OemId)] = '\0';
73 setenv("hint.acpi.0.oem", buf, 1);
74 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress);
75 setenv("hint.acpi.0.rsdt", buf, 1);
76 if (revision >= 2) {
77 /* XXX extended checksum? */
78 sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress);
79 setenv("hint.acpi.0.xsdt", buf, 1);
80 sprintf(buf, "%d", rsdp->Length);
81 setenv("hint.acpi.0.xsdt_length", buf, 1);
82 }
83 }
84
85 /*
86 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec.
87 */
88 static ACPI_TABLE_RSDP *
biosacpi_find_rsdp(void)89 biosacpi_find_rsdp(void)
90 {
91 ACPI_TABLE_RSDP *rsdp;
92 uint16_t *addr;
93
94 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */
95 addr = (uint16_t *)PTOV(0x40E);
96 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL)
97 return (rsdp);
98
99 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */
100 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL)
101 return (rsdp);
102
103 return (NULL);
104 }
105
106 static ACPI_TABLE_RSDP *
biosacpi_search_rsdp(char * base,int length)107 biosacpi_search_rsdp(char *base, int length)
108 {
109 ACPI_TABLE_RSDP *rsdp;
110 u_int8_t *cp, sum;
111 int ofs, idx;
112
113 /* search on 16-byte boundaries */
114 for (ofs = 0; ofs < length; ofs += 16) {
115 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs);
116
117 /* compare signature, validate checksum */
118 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) {
119 cp = (u_int8_t *)rsdp;
120 sum = 0;
121 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++)
122 sum += *(cp + idx);
123 if (sum != 0)
124 continue;
125 return(rsdp);
126 }
127 }
128 return(NULL);
129 }
130