xref: /freebsd/sys/dev/acpica/Osd/OsdTable.c (revision 7bd6fde3)
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 
27 /*
28  * ACPI Table interfaces
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/endian.h>
36 #include <sys/kernel.h>
37 #include <sys/linker.h>
38 
39 #include <contrib/dev/acpica/acpi.h>
40 #include <contrib/dev/acpica/actables.h>
41 
42 #undef _COMPONENT
43 #define _COMPONENT      ACPI_TABLES
44 
45 static char acpi_osname[128];
46 TUNABLE_STR("hw.acpi.osname", acpi_osname, sizeof(acpi_osname));
47 
48 static struct {
49     ACPI_TABLE_HEADER_DEF
50     uint32_t no_op;
51 } __packed fake_ssdt;
52 
53 ACPI_STATUS
54 AcpiOsPredefinedOverride (
55     const ACPI_PREDEFINED_NAMES *InitVal,
56     ACPI_STRING                 *NewVal)
57 {
58     if (InitVal == NULL || NewVal == NULL)
59 	return (AE_BAD_PARAMETER);
60 
61     *NewVal = NULL;
62     if (strncmp(InitVal->Name, "_OS_", 4) == 0 && strlen(acpi_osname) > 0) {
63 	printf("ACPI: Overriding _OS definition with \"%s\"\n", acpi_osname);
64 	*NewVal = acpi_osname;
65     }
66 
67     return (AE_OK);
68 }
69 
70 ACPI_STATUS
71 AcpiOsTableOverride (
72     ACPI_TABLE_HEADER       *ExistingTable,
73     ACPI_TABLE_HEADER       **NewTable)
74 {
75     caddr_t acpi_dsdt, p;
76 
77     if (ExistingTable == NULL || NewTable == NULL)
78 	return (AE_BAD_PARAMETER);
79 
80     /* If we're not overriding the DSDT, just return. */
81     *NewTable = NULL;
82     if ((acpi_dsdt = preload_search_by_type("acpi_dsdt")) == NULL)
83 	return (AE_OK);
84     if ((p = preload_search_info(acpi_dsdt, MODINFO_ADDR)) == NULL)
85 	return (AE_OK);
86 
87     /*
88      * Override the DSDT with the user's custom version.  Override the
89      * contents of any SSDTs with a simple no-op table since the user's
90      * DSDT is expected to contain their contents as well.
91      */
92     if (strncmp(ExistingTable->Signature, "DSDT", 4) == 0) {
93 	printf("ACPI: overriding DSDT/SSDT with custom table\n");
94 	*NewTable = *(void **)p;
95     } else if (strncmp(ExistingTable->Signature, "SSDT", 4) == 0) {
96 	if (fake_ssdt.Length == 0) {
97 	    sprintf(fake_ssdt.Signature, "%.4s", "SSDT");
98 	    fake_ssdt.Length = htole32(sizeof(fake_ssdt));
99 	    fake_ssdt.Revision = 2;
100 	    fake_ssdt.Checksum = 0;
101 	    sprintf(fake_ssdt.OemId, "%.6s", "FBSD  ");
102 	    sprintf(fake_ssdt.OemTableId, "%.8s", "NullSSDT");
103 	    fake_ssdt.OemRevision = htole32(1);
104 	    sprintf(fake_ssdt.AslCompilerId, "%.4s", "FBSD");
105 	    fake_ssdt.AslCompilerRevision = htole32(1);
106 	    fake_ssdt.no_op = htole32(0x005c0310); /* Scope(\) */
107 	    fake_ssdt.Checksum -= AcpiTbGenerateChecksum(&fake_ssdt,
108 		sizeof(fake_ssdt));
109 	}
110 	*NewTable = (void *)&fake_ssdt;
111     }
112 
113     return (AE_OK);
114 }
115