2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000,2001 Michael Smith
5 * Copyright (c) 2000 BSDi
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
38 #include <contrib/dev/acpica/include/acpi.h>
39 #include <contrib/dev/acpica/include/aclocal.h>
40 #include <contrib/dev/acpica/include/actables.h>
42 static u_long acpi_root_phys;
44 SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &acpi_root_phys, 0,
45 "The physical address of the RSDP");
48 AcpiOsInitialize(void)
62 acpi_get_root_from_loader(void)
66 if (TUNABLE_ULONG_FETCH("acpi.rsdp", &acpi_root))
70 * The hints mechanism is unreliable (it fails if anybody ever
71 * compiled in hints to the kernel). It has been replaced
72 * by the tunable method, but is used here as a fallback to
73 * retain maximum compatibility between old loaders and new
74 * kernels. It can be removed after 11.0R.
76 if (resource_long_value("acpi", 0, "rsdp", &acpi_root) == 0)
83 acpi_get_root_from_memory(void)
85 ACPI_PHYSICAL_ADDRESS acpi_root;
87 if (ACPI_SUCCESS(AcpiFindRootPointer(&acpi_root)))
94 AcpiOsGetRootPointer(void)
97 if (acpi_root_phys == 0) {
98 acpi_root_phys = acpi_get_root_from_loader();
99 if (acpi_root_phys == 0)
100 acpi_root_phys = acpi_get_root_from_memory();
103 return (acpi_root_phys);