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 <stand.h>
28 #include <machine/stdarg.h>
29 #include <bootstrap.h>
30 #include <btxv86.h>
31 #include "libi386.h"
32
33 #include "platform/acfreebsd.h"
34 #include "acconfig.h"
35 #define ACPI_SYSTEM_XFACE
36 #include "actypes.h"
37 #include "actbl.h"
38
39 /*
40 * Detect ACPI and export information about the ACPI BIOS into the
41 * environment.
42 */
43
44 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void);
45 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length);
46
47 #define RSDP_CHECKSUM_LENGTH 20
48
49 void
biosacpi_detect(void)50 biosacpi_detect(void)
51 {
52 ACPI_TABLE_RSDP *rsdp;
53 char buf[24];
54 int revision;
55
56 feature_enable(FEATURE_EARLY_ACPI);
57
58 /* locate and validate the RSDP */
59 if ((rsdp = biosacpi_find_rsdp()) == NULL)
60 return;
61
62 /*
63 * Report the RSDP to the kernel. While this can be found with
64 * a BIOS boot, the RSDP may be elsewhere when booted from UEFI.
65 */
66 sprintf(buf, "0x%08x", VTOP(rsdp));
67 setenv("acpi.rsdp", buf, 1);
68 revision = rsdp->Revision;
69 if (revision == 0)
70 revision = 1;
71 sprintf(buf, "%d", revision);
72 setenv("acpi.revision", buf, 1);
73 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId));
74 buf[sizeof(rsdp->OemId)] = '\0';
75 setenv("acpi.oem", buf, 1);
76 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress);
77 setenv("acpi.rsdt", buf, 1);
78 if (revision >= 2) {
79 /* XXX extended checksum? */
80 sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress);
81 setenv("acpi.xsdt", buf, 1);
82 sprintf(buf, "%d", rsdp->Length);
83 setenv("acpi.xsdt_length", buf, 1);
84 }
85 }
86
87 /*
88 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec.
89 */
90 static ACPI_TABLE_RSDP *
biosacpi_find_rsdp(void)91 biosacpi_find_rsdp(void)
92 {
93 ACPI_TABLE_RSDP *rsdp;
94 uint16_t *addr;
95
96 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */
97 addr = (uint16_t *)PTOV(0x40E);
98 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL)
99 return (rsdp);
100
101 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */
102 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL)
103 return (rsdp);
104
105 return (NULL);
106 }
107
108 static ACPI_TABLE_RSDP *
biosacpi_search_rsdp(char * base,int length)109 biosacpi_search_rsdp(char *base, int length)
110 {
111 ACPI_TABLE_RSDP *rsdp;
112 uint8_t *cp, sum;
113 int ofs, idx;
114
115 /* search on 16-byte boundaries */
116 for (ofs = 0; ofs < length; ofs += 16) {
117 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs);
118
119 /* compare signature, validate checksum */
120 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) {
121 cp = (uint8_t *)rsdp;
122 sum = 0;
123 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++)
124 sum += *(cp + idx);
125 if (sum != 0)
126 continue;
127 return(rsdp);
128 }
129 }
130 return(NULL);
131 }
132