/****************************************************************************** * * Module Name: tbxfroot - Find the root ACPI table (RSDT) * $Revision: 1.106 $ * *****************************************************************************/ /****************************************************************************** * * 1. Copyright Notice * * Some or all of this work - Copyright (c) 1999 - 2008, Intel Corp. * All rights reserved. * * 2. License * * 2.1. This is your license from Intel Corp. under its intellectual property * rights. You may have additional license terms from the party that provided * you this software, covering your right to use that party's intellectual * property rights. * * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a * copy of the source code appearing in this file ("Covered Code") an * irrevocable, perpetual, worldwide license under Intel's copyrights in the * base code distributed originally by Intel ("Original Intel Code") to copy, * make derivatives, distribute, use and display any portion of the Covered * Code in any form, with the right to sublicense such rights; and * * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent * license (with the right to sublicense), under only those claims of Intel * patents that are infringed by the Original Intel Code, to make, use, sell, * offer to sell, and import the Covered Code and derivative works thereof * solely to the minimum extent necessary to exercise the above copyright * license, and in no event shall the patent license extend to any additions * to or modifications of the Original Intel Code. No other license or right * is granted directly or by implication, estoppel or otherwise; * * The above copyright and patent license is granted only if the following * conditions are met: * * 3. Conditions * * 3.1. Redistribution of Source with Rights to Further Distribute Source. * Redistribution of source code of any substantial portion of the Covered * Code or modification with rights to further distribute source must include * the above Copyright Notice, the above License, this list of Conditions, * and the following Disclaimer and Export Compliance provision. In addition, * Licensee must cause all Covered Code to which Licensee contributes to * contain a file documenting the changes Licensee made to create that Covered * Code and the date of any change. Licensee must include in that file the * documentation of any changes made by any predecessor Licensee. Licensee * must include a prominent statement that the modification is derived, * directly or indirectly, from Original Intel Code. * * 3.2. Redistribution of Source with no Rights to Further Distribute Source. * Redistribution of source code of any substantial portion of the Covered * Code or modification without rights to further distribute source must * include the following Disclaimer and Export Compliance provision in the * documentation and/or other materials provided with distribution. In * addition, Licensee may not authorize further sublicense of source of any * portion of the Covered Code, and must include terms to the effect that the * license from Licensee to its licensee is limited to the intellectual * property embodied in the software Licensee provides to its licensee, and * not to intellectual property embodied in modifications its licensee may * make. * * 3.3. Redistribution of Executable. Redistribution in executable form of any * substantial portion of the Covered Code or modification must reproduce the * above Copyright Notice, and the following Disclaimer and Export Compliance * provision in the documentation and/or other materials provided with the * distribution. * * 3.4. Intel retains all right, title, and interest in and to the Original * Intel Code. * * 3.5. Neither the name Intel nor any other trademark owned or controlled by * Intel shall be used in advertising or otherwise to promote the sale, use or * other dealings in products derived from or relating to the Covered Code * without prior written authorization from Intel. * * 4. Disclaimer and Export Compliance * * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A * PARTICULAR PURPOSE. * * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY * LIMITED REMEDY. * * 4.3. Licensee shall not export, either directly or indirectly, any of this * software or system incorporating such software without first obtaining any * required license or other approval from the U. S. Department of Commerce or * any other agency or department of the United States Government. In the * event Licensee exports any such software from the United States or * re-exports any such software from a foreign destination, Licensee shall * ensure that the distribution and export/re-export of the software is in * compliance with all laws, regulations, orders, or other restrictions of the * U.S. Export Administration Regulations. Licensee agrees that neither it nor * any of its subsidiaries will export/re-export any technical data, process, * software, or service, directly or indirectly, to any country for which the * United States government or any agency thereof requires an export license, * other governmental approval, or letter of assurance, without first obtaining * such license, approval or letter. * *****************************************************************************/ #define __TBXFROOT_C__ #include "acpi.h" #include "actables.h" #define _COMPONENT ACPI_TABLES ACPI_MODULE_NAME ("tbxfroot") /* Local prototypes */ static UINT8 * AcpiTbScanMemoryForRsdp ( UINT8 *StartAddress, UINT32 Length); static ACPI_STATUS AcpiTbValidateRsdp ( ACPI_TABLE_RSDP *Rsdp); /******************************************************************************* * * FUNCTION: AcpiTbValidateRsdp * * PARAMETERS: Rsdp - Pointer to unvalidated RSDP * * RETURN: Status * * DESCRIPTION: Validate the RSDP (ptr) * ******************************************************************************/ static ACPI_STATUS AcpiTbValidateRsdp ( ACPI_TABLE_RSDP *Rsdp) { ACPI_FUNCTION_ENTRY (); /* * The signature and checksum must both be correct * * Note: Sometimes there exists more than one RSDP in memory; the valid * RSDP has a valid checksum, all others have an invalid checksum. */ if (ACPI_STRNCMP ((char *) Rsdp, ACPI_SIG_RSDP, sizeof (ACPI_SIG_RSDP)-1) != 0) { /* Nope, BAD Signature */ return (AE_BAD_SIGNATURE); } /* Check the standard checksum */ if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) { return (AE_BAD_CHECKSUM); } /* Check extended checksum if table version >= 2 */ if ((Rsdp->Revision >= 2) && (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) { return (AE_BAD_CHECKSUM); } return (AE_OK); } /******************************************************************************* * * FUNCTION: AcpiTbFindRsdp * * PARAMETERS: TableAddress - Where the table pointer is returned * * RETURN: Status, RSDP physical address * * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor * pointer structure. If it is found, set *RSDP to point to it. * * NOTE1: The RSDP must be either in the first 1K of the Extended * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) * Only a 32-bit physical address is necessary. * * NOTE2: This function is always available, regardless of the * initialization state of the rest of ACPI. * ******************************************************************************/ ACPI_STATUS AcpiFindRootPointer ( ACPI_SIZE *TableAddress) { UINT8 *TablePtr; UINT8 *MemRover; UINT32 PhysicalAddress; ACPI_FUNCTION_TRACE (AcpiFindRootPointer); /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ TablePtr = AcpiOsMapMemory ( (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH); if (!TablePtr) { ACPI_ERROR ((AE_INFO, "Could not map memory at %8.8X for length %X", ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); return_ACPI_STATUS (AE_NO_MEMORY); } ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); /* Convert segment part to physical address */ PhysicalAddress <<= 4; AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); /* EBDA present? */ if (PhysicalAddress > 0x400) { /* * 1b) Search EBDA paragraphs (EBDA is required to be a * minimum of 1K length) */ TablePtr = AcpiOsMapMemory ( (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, ACPI_EBDA_WINDOW_SIZE); if (!TablePtr) { ACPI_ERROR ((AE_INFO, "Could not map memory at %8.8X for length %X", PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); return_ACPI_STATUS (AE_NO_MEMORY); } MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE); AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); if (MemRover) { /* Return the physical address */ PhysicalAddress += (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); *TableAddress = PhysicalAddress; return_ACPI_STATUS (AE_OK); } } /* * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */ TablePtr = AcpiOsMapMemory ( (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE); if (!TablePtr) { ACPI_ERROR ((AE_INFO, "Could not map memory at %8.8X for length %X", ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); return_ACPI_STATUS (AE_NO_MEMORY); } MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); if (MemRover) { /* Return the physical address */ PhysicalAddress = (UINT32) (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); *TableAddress = PhysicalAddress; return_ACPI_STATUS (AE_OK); } /* A valid RSDP was not found */ ACPI_ERROR ((AE_INFO, "A valid RSDP was not found")); return_ACPI_STATUS (AE_NOT_FOUND); } ACPI_EXPORT_SYMBOL (AcpiFindRootPointer) /******************************************************************************* * * FUNCTION: AcpiTbScanMemoryForRsdp * * PARAMETERS: StartAddress - Starting pointer for search * Length - Maximum length to search * * RETURN: Pointer to the RSDP if found, otherwise NULL. * * DESCRIPTION: Search a block of memory for the RSDP signature * ******************************************************************************/ static UINT8 * AcpiTbScanMemoryForRsdp ( UINT8 *StartAddress, UINT32 Length) { ACPI_STATUS Status; UINT8 *MemRover; UINT8 *EndAddress; ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); EndAddress = StartAddress + Length; /* Search from given start address for the requested length */ for (MemRover = StartAddress; MemRover < EndAddress; MemRover += ACPI_RSDP_SCAN_STEP) { /* The RSDP signature and checksum must both be correct */ Status = AcpiTbValidateRsdp (ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); if (ACPI_SUCCESS (Status)) { /* Sig and checksum valid, we have found a real RSDP */ ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "RSDP located at physical address %p\n", MemRover)); return_PTR (MemRover); } /* No sig match or bad checksum, keep searching */ } /* Searched entire block, no RSDP was found */ ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Searched entire block from %p, valid RSDP was not found\n", StartAddress)); return_PTR (NULL); }