1 /******************************************************************************
3 * Module Name: tbxfroot - Find the root ACPI table (RSDT)
6 *****************************************************************************/
8 /******************************************************************************
12 * Some or all of this work - Copyright (c) 1999 - 2007, Intel Corp.
13 * All rights reserved.
17 * 2.1. This is your license from Intel Corp. under its intellectual property
18 * rights. You may have additional license terms from the party that provided
19 * you this software, covering your right to use that party's intellectual
22 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
23 * copy of the source code appearing in this file ("Covered Code") an
24 * irrevocable, perpetual, worldwide license under Intel's copyrights in the
25 * base code distributed originally by Intel ("Original Intel Code") to copy,
26 * make derivatives, distribute, use and display any portion of the Covered
27 * Code in any form, with the right to sublicense such rights; and
29 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
30 * license (with the right to sublicense), under only those claims of Intel
31 * patents that are infringed by the Original Intel Code, to make, use, sell,
32 * offer to sell, and import the Covered Code and derivative works thereof
33 * solely to the minimum extent necessary to exercise the above copyright
34 * license, and in no event shall the patent license extend to any additions
35 * to or modifications of the Original Intel Code. No other license or right
36 * is granted directly or by implication, estoppel or otherwise;
38 * The above copyright and patent license is granted only if the following
43 * 3.1. Redistribution of Source with Rights to Further Distribute Source.
44 * Redistribution of source code of any substantial portion of the Covered
45 * Code or modification with rights to further distribute source must include
46 * the above Copyright Notice, the above License, this list of Conditions,
47 * and the following Disclaimer and Export Compliance provision. In addition,
48 * Licensee must cause all Covered Code to which Licensee contributes to
49 * contain a file documenting the changes Licensee made to create that Covered
50 * Code and the date of any change. Licensee must include in that file the
51 * documentation of any changes made by any predecessor Licensee. Licensee
52 * must include a prominent statement that the modification is derived,
53 * directly or indirectly, from Original Intel Code.
55 * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
56 * Redistribution of source code of any substantial portion of the Covered
57 * Code or modification without rights to further distribute source must
58 * include the following Disclaimer and Export Compliance provision in the
59 * documentation and/or other materials provided with distribution. In
60 * addition, Licensee may not authorize further sublicense of source of any
61 * portion of the Covered Code, and must include terms to the effect that the
62 * license from Licensee to its licensee is limited to the intellectual
63 * property embodied in the software Licensee provides to its licensee, and
64 * not to intellectual property embodied in modifications its licensee may
67 * 3.3. Redistribution of Executable. Redistribution in executable form of any
68 * substantial portion of the Covered Code or modification must reproduce the
69 * above Copyright Notice, and the following Disclaimer and Export Compliance
70 * provision in the documentation and/or other materials provided with the
73 * 3.4. Intel retains all right, title, and interest in and to the Original
76 * 3.5. Neither the name Intel nor any other trademark owned or controlled by
77 * Intel shall be used in advertising or otherwise to promote the sale, use or
78 * other dealings in products derived from or relating to the Covered Code
79 * without prior written authorization from Intel.
81 * 4. Disclaimer and Export Compliance
83 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
84 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
85 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
86 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
87 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
88 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
91 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
92 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
93 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
94 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
95 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
96 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
97 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
100 * 4.3. Licensee shall not export, either directly or indirectly, any of this
101 * software or system incorporating such software without first obtaining any
102 * required license or other approval from the U. S. Department of Commerce or
103 * any other agency or department of the United States Government. In the
104 * event Licensee exports any such software from the United States or
105 * re-exports any such software from a foreign destination, Licensee shall
106 * ensure that the distribution and export/re-export of the software is in
107 * compliance with all laws, regulations, orders, or other restrictions of the
108 * U.S. Export Administration Regulations. Licensee agrees that neither it nor
109 * any of its subsidiaries will export/re-export any technical data, process,
110 * software, or service, directly or indirectly, to any country for which the
111 * United States government or any agency thereof requires an export license,
112 * other governmental approval, or letter of assurance, without first obtaining
113 * such license, approval or letter.
115 *****************************************************************************/
117 #define __TBXFROOT_C__
119 #include <contrib/dev/acpica/acpi.h>
120 #include <contrib/dev/acpica/actables.h>
123 #define _COMPONENT ACPI_TABLES
124 ACPI_MODULE_NAME ("tbxfroot")
126 /* Local prototypes */
129 AcpiTbScanMemoryForRsdp (
135 ACPI_TABLE_RSDP *Rsdp);
138 /*******************************************************************************
140 * FUNCTION: AcpiTbValidateRsdp
142 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP
146 * DESCRIPTION: Validate the RSDP (ptr)
148 ******************************************************************************/
152 ACPI_TABLE_RSDP *Rsdp)
154 ACPI_FUNCTION_ENTRY ();
158 * The signature and checksum must both be correct
160 * Note: Sometimes there exists more than one RSDP in memory; the valid
161 * RSDP has a valid checksum, all others have an invalid checksum.
163 if (ACPI_STRNCMP ((char *) Rsdp, ACPI_SIG_RSDP, sizeof (ACPI_SIG_RSDP)-1) != 0)
165 /* Nope, BAD Signature */
167 return (AE_BAD_SIGNATURE);
170 /* Check the standard checksum */
172 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0)
174 return (AE_BAD_CHECKSUM);
177 /* Check extended checksum if table version >= 2 */
179 if ((Rsdp->Revision >= 2) &&
180 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0))
182 return (AE_BAD_CHECKSUM);
189 /*******************************************************************************
191 * FUNCTION: AcpiTbFindRsdp
193 * PARAMETERS: TableAddress - Where the table pointer is returned
195 * RETURN: Status, RSDP physical address
197 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor
198 * pointer structure. If it is found, set *RSDP to point to it.
200 * NOTE1: The RSDP must be either in the first 1K of the Extended
201 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
202 * Only a 32-bit physical address is necessary.
204 * NOTE2: This function is always available, regardless of the
205 * initialization state of the rest of ACPI.
207 ******************************************************************************/
210 AcpiFindRootPointer (
211 ACPI_NATIVE_UINT *TableAddress)
215 UINT32 PhysicalAddress;
218 ACPI_FUNCTION_TRACE (AcpiFindRootPointer);
221 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
223 TablePtr = AcpiOsMapMemory (
224 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION,
225 ACPI_EBDA_PTR_LENGTH);
228 ACPI_ERROR ((AE_INFO,
229 "Could not map memory at %8.8X for length %X",
230 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
232 return_ACPI_STATUS (AE_NO_MEMORY);
235 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr);
237 /* Convert segment part to physical address */
239 PhysicalAddress <<= 4;
240 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH);
244 if (PhysicalAddress > 0x400)
247 * 1b) Search EBDA paragraphs (EBDA is required to be a
248 * minimum of 1K length)
250 TablePtr = AcpiOsMapMemory (
251 (ACPI_NATIVE_UINT) PhysicalAddress,
252 ACPI_EBDA_WINDOW_SIZE);
255 ACPI_ERROR ((AE_INFO,
256 "Could not map memory at %8.8X for length %X",
257 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE));
259 return_ACPI_STATUS (AE_NO_MEMORY);
262 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE);
263 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE);
267 /* Return the physical address */
269 PhysicalAddress += (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr);
271 *TableAddress = PhysicalAddress;
272 return_ACPI_STATUS (AE_OK);
277 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
279 TablePtr = AcpiOsMapMemory (
280 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE,
281 ACPI_HI_RSDP_WINDOW_SIZE);
285 ACPI_ERROR ((AE_INFO,
286 "Could not map memory at %8.8X for length %X",
287 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE));
289 return_ACPI_STATUS (AE_NO_MEMORY);
292 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
293 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
297 /* Return the physical address */
299 PhysicalAddress = (UINT32)
300 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr));
302 *TableAddress = PhysicalAddress;
303 return_ACPI_STATUS (AE_OK);
306 /* A valid RSDP was not found */
308 ACPI_ERROR ((AE_INFO, "A valid RSDP was not found"));
309 return_ACPI_STATUS (AE_NOT_FOUND);
312 ACPI_EXPORT_SYMBOL (AcpiFindRootPointer)
315 /*******************************************************************************
317 * FUNCTION: AcpiTbScanMemoryForRsdp
319 * PARAMETERS: StartAddress - Starting pointer for search
320 * Length - Maximum length to search
322 * RETURN: Pointer to the RSDP if found, otherwise NULL.
324 * DESCRIPTION: Search a block of memory for the RSDP signature
326 ******************************************************************************/
329 AcpiTbScanMemoryForRsdp (
338 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp);
341 EndAddress = StartAddress + Length;
343 /* Search from given start address for the requested length */
345 for (MemRover = StartAddress; MemRover < EndAddress;
346 MemRover += ACPI_RSDP_SCAN_STEP)
348 /* The RSDP signature and checksum must both be correct */
350 Status = AcpiTbValidateRsdp (ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover));
351 if (ACPI_SUCCESS (Status))
353 /* Sig and checksum valid, we have found a real RSDP */
355 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
356 "RSDP located at physical address %p\n", MemRover));
357 return_PTR (MemRover);
360 /* No sig match or bad checksum, keep searching */
363 /* Searched entire block, no RSDP was found */
365 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
366 "Searched entire block from %p, valid RSDP was not found\n",