2 * Copyright (c) 2001 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/sys/boot/i386/libi386/biosacpi.c,v 1.7 2003/08/25 23:28:31 obrien Exp $
27 * $DragonFly: src/sys/boot/pc32/libi386/biosacpi.c,v 1.5 2007/01/17 17:31:19 y0netan1 Exp $
31 #include <machine/stdarg.h>
32 #include <bootstrap.h>
36 #include "acdragonfly.h"
38 #define ACPI_SYSTEM_XFACE
43 * Detect ACPI and export information about the APCI BIOS into the
47 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void);
48 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length);
50 #define RSDP_CHECKSUM_LENGTH 20
55 ACPI_TABLE_RSDP *rsdp;
59 /* XXX check the BIOS datestamp */
61 /* locate and validate the RSDP */
62 if ((rsdp = biosacpi_find_rsdp()) == NULL)
65 /* export values from the RSDP */
66 revision = rsdp->Revision;
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);
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);
83 /* XXX other tables? */
85 setenv("acpi_load", "YES", 1);
89 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec.
91 static ACPI_TABLE_RSDP *
92 biosacpi_find_rsdp(void)
94 ACPI_TABLE_RSDP *rsdp;
97 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */
98 addr = (uint16_t *)PTOV(0x40E);
99 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL)
102 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */
103 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL)
109 static ACPI_TABLE_RSDP *
110 biosacpi_search_rsdp(char *base, int length)
112 ACPI_TABLE_RSDP *rsdp;
116 /* search on 16-byte boundaries */
117 for (ofs = 0; ofs < length; ofs += 16) {
118 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs);
120 /* compare signature, validate checksum */
121 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) {
122 cp = (u_int8_t *)rsdp;
124 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++)
127 printf("acpi: bad RSDP checksum (%d)\n", sum);