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 $
30 #include <machine/stdarg.h>
31 #include <bootstrap.h>
35 #include "platform/acdragonfly.h"
37 #define ACPI_SYSTEM_XFACE
42 * Detect ACPI and export information about the ACPI BIOS into the
46 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void);
47 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length);
49 #define RSDP_CHECKSUM_LENGTH 20
54 ACPI_TABLE_RSDP *rsdp;
58 /* locate and validate the RSDP */
59 if ((rsdp = biosacpi_find_rsdp()) == NULL)
62 /* export values from the RSDP */
63 revision = rsdp->Revision;
66 sprintf(buf, "%d", revision);
67 setenv("hint.acpi.0.revision", buf, 1);
68 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId));
69 buf[sizeof(rsdp->OemId)] = '\0';
70 setenv("hint.acpi.0.oem", buf, 1);
71 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress);
72 setenv("hint.acpi.0.rsdt", buf, 1);
74 /* XXX extended checksum? */
75 sprintf(buf, "0x%016jx", (uintmax_t)rsdp->XsdtPhysicalAddress);
76 setenv("hint.acpi.0.xsdt", buf, 1);
77 sprintf(buf, "%d", rsdp->Length);
78 setenv("hint.acpi.0.xsdt_length", buf, 1);
80 setenv("acpi_load", "YES", 1);
84 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec.
86 static ACPI_TABLE_RSDP *
87 biosacpi_find_rsdp(void)
89 ACPI_TABLE_RSDP *rsdp;
92 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */
93 addr = (uint16_t *)PTOV(0x40E);
94 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL)
97 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */
98 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL)
104 static ACPI_TABLE_RSDP *
105 biosacpi_search_rsdp(char *base, int length)
107 ACPI_TABLE_RSDP *rsdp;
111 /* search on 16-byte boundaries */
112 for (ofs = 0; ofs < length; ofs += 16) {
113 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs);
115 /* compare signature, validate checksum */
116 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) {
117 cp = (u_int8_t *)rsdp;
119 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++)