xref: /freebsd/sys/dev/acpica/Osd/OsdTable.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
1 /*-
2  * Copyright (c) 2002 Mitsaru Iwasaki
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  *	$FreeBSD$
27  */
28 
29 /*
30  * ACPI Table interfaces
31  */
32 
33 #include <sys/param.h>
34 #include <sys/endian.h>
35 #include <sys/kernel.h>
36 #include <sys/linker.h>
37 
38 #include "acpi.h"
39 #include <contrib/dev/acpica/actables.h>
40 
41 #undef _COMPONENT
42 #define _COMPONENT      ACPI_TABLES
43 
44 static char acpi_osname[128];
45 TUNABLE_STR("hw.acpi.osname", acpi_osname, sizeof(acpi_osname));
46 
47 static struct {
48     ACPI_TABLE_HEADER_DEF
49     uint32_t no_op;
50 } __packed fake_ssdt;
51 
52 ACPI_STATUS
53 AcpiOsPredefinedOverride (
54     const ACPI_PREDEFINED_NAMES *InitVal,
55     ACPI_STRING                 *NewVal)
56 {
57     if (InitVal == NULL || NewVal == NULL)
58 	return (AE_BAD_PARAMETER);
59 
60     *NewVal = NULL;
61     if (strncmp(InitVal->Name, "_OS_", 4) == 0 && strlen(acpi_osname) > 0) {
62 	printf("ACPI: Overriding _OS definition with \"%s\"\n", acpi_osname);
63 	*NewVal = acpi_osname;
64     }
65 
66     return (AE_OK);
67 }
68 
69 ACPI_STATUS
70 AcpiOsTableOverride (
71     ACPI_TABLE_HEADER       *ExistingTable,
72     ACPI_TABLE_HEADER       **NewTable)
73 {
74     caddr_t acpi_dsdt, p;
75 
76     if (ExistingTable == NULL || NewTable == NULL)
77 	return (AE_BAD_PARAMETER);
78 
79     /* If we're not overriding the DSDT, just return. */
80     *NewTable = NULL;
81     if ((acpi_dsdt = preload_search_by_type("acpi_dsdt")) == NULL)
82 	return (AE_OK);
83     if ((p = preload_search_info(acpi_dsdt, MODINFO_ADDR)) == NULL)
84 	return (AE_OK);
85 
86     /*
87      * Override the DSDT with the user's custom version.  Override the
88      * contents of any SSDTs with a simple no-op table since the user's
89      * DSDT is expected to contain their contents as well.
90      */
91     if (strncmp(ExistingTable->Signature, "DSDT", 4) == 0) {
92 	printf("ACPI: overriding DSDT/SSDT with custom table\n");
93 	*NewTable = *(void **)p;
94     } else if (strncmp(ExistingTable->Signature, "SSDT", 4) == 0) {
95 	if (fake_ssdt.Length == 0) {
96 	    sprintf(fake_ssdt.Signature, "%.4s", "SSDT");
97 	    fake_ssdt.Length = htole32(sizeof(fake_ssdt));
98 	    fake_ssdt.Revision = 2;
99 	    fake_ssdt.Checksum = 0;
100 	    sprintf(fake_ssdt.OemId, "%.6s", "FBSD  ");
101 	    sprintf(fake_ssdt.OemTableId, "%.8s", "NullSSDT");
102 	    fake_ssdt.OemRevision = htole32(1);
103 	    sprintf(fake_ssdt.AslCompilerId, "%.4s", "FBSD");
104 	    fake_ssdt.AslCompilerRevision = htole32(1);
105 	    fake_ssdt.no_op = htole32(0x005c0310); /* Scope(\) */
106 	    fake_ssdt.Checksum -= AcpiTbChecksum(&fake_ssdt, sizeof(fake_ssdt));
107 	}
108 	*NewTable = (void *)&fake_ssdt;
109     }
110 
111     return (AE_OK);
112 }
113