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aetables.c revision 1.1.1.17
      1 /******************************************************************************
      2  *
      3  * Module Name: aetables - ACPI table setup/install for acpiexec utility
      4  *
      5  *****************************************************************************/
      6 
      7 /*
      8  * Copyright (C) 2000 - 2022, Intel Corp.
      9  * All rights reserved.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions, and the following disclaimer,
     16  *    without modification.
     17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
     18  *    substantially similar to the "NO WARRANTY" disclaimer below
     19  *    ("Disclaimer") and any redistribution must be conditioned upon
     20  *    including a substantially similar Disclaimer requirement for further
     21  *    binary redistribution.
     22  * 3. Neither the names of the above-listed copyright holders nor the names
     23  *    of any contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * Alternatively, this software may be distributed under the terms of the
     27  * GNU General Public License ("GPL") version 2 as published by the Free
     28  * Software Foundation.
     29  *
     30  * NO WARRANTY
     31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     41  * POSSIBILITY OF SUCH DAMAGES.
     42  */
     43 
     44 #include "aecommon.h"
     45 #include "aetables.h"
     46 
     47 #define _COMPONENT          ACPI_TOOLS
     48         ACPI_MODULE_NAME    ("aetables")
     49 
     50 /* Local prototypes */
     51 
     52 static void
     53 AeInitializeTableHeader (
     54     ACPI_TABLE_HEADER       *Header,
     55     char                    *Signature,
     56     UINT32                  Length);
     57 
     58 void
     59 AeTableOverride (
     60     ACPI_TABLE_HEADER       *ExistingTable,
     61     ACPI_TABLE_HEADER       **NewTable);
     62 
     63 /* User table (DSDT) */
     64 
     65 static ACPI_TABLE_HEADER        *DsdtToInstallOverride;
     66 
     67 /* Non-AML tables that are constructed locally and installed */
     68 
     69 static ACPI_TABLE_RSDP          LocalRSDP;
     70 static ACPI_TABLE_FACS          LocalFACS;
     71 static ACPI_TABLE_HEADER        LocalTEST;
     72 static ACPI_TABLE_HEADER        LocalBADTABLE;
     73 
     74 /*
     75  * We need a local FADT so that the hardware subcomponent will function,
     76  * even though the underlying OSD HW access functions don't do anything.
     77  */
     78 static ACPI_TABLE_FADT          LocalFADT;
     79 
     80 /*
     81  * Use XSDT so that both 32- and 64-bit versions of this utility will
     82  * function automatically.
     83  */
     84 static ACPI_TABLE_XSDT          *LocalXSDT;
     85 
     86 #define BASE_XSDT_TABLES        9
     87 #define BASE_XSDT_SIZE          ((BASE_XSDT_TABLES) * sizeof (UINT64))
     88 
     89 #define ACPI_MAX_INIT_TABLES    (32)
     90 
     91 
     92 /******************************************************************************
     93  *
     94  * FUNCTION:    AeTableOverride
     95  *
     96  * DESCRIPTION: Local implementation of AcpiOsTableOverride.
     97  *              Exercise the override mechanism
     98  *
     99  *****************************************************************************/
    100 
    101 void
    102 AeTableOverride (
    103     ACPI_TABLE_HEADER       *ExistingTable,
    104     ACPI_TABLE_HEADER       **NewTable)
    105 {
    106 
    107     if (!AcpiGbl_LoadTestTables)
    108     {
    109         *NewTable = NULL;
    110         return;
    111     }
    112 
    113     /* This code exercises the table override mechanism in the core */
    114 
    115     if (ACPI_COMPARE_NAMESEG (ExistingTable->Signature, ACPI_SIG_DSDT))
    116     {
    117         *NewTable = DsdtToInstallOverride;
    118     }
    119 
    120     /* This code tests override of dynamically loaded tables */
    121 
    122     else if (ACPI_COMPARE_NAMESEG (ExistingTable->Signature, "OEM9"))
    123     {
    124         *NewTable = ACPI_CAST_PTR (ACPI_TABLE_HEADER, Ssdt3Code);
    125     }
    126 }
    127 
    128 
    129 /******************************************************************************
    130  *
    131  * FUNCTION:    AeInitializeTableHeader
    132  *
    133  * PARAMETERS:  Header          - A valid standard ACPI table header
    134  *              Signature       - Signature to insert
    135  *              Length          - Length of the table
    136  *
    137  * RETURN:      None. Header is modified.
    138  *
    139  * DESCRIPTION: Initialize the table header for a local ACPI table.
    140  *
    141  *****************************************************************************/
    142 
    143 static void
    144 AeInitializeTableHeader (
    145     ACPI_TABLE_HEADER       *Header,
    146     char                    *Signature,
    147     UINT32                  Length)
    148 {
    149 
    150     ACPI_COPY_NAMESEG (Header->Signature, Signature);
    151     Header->Length = Length;
    152 
    153     Header->OemRevision = 0x1001;
    154     memcpy (Header->OemId, "Intel ", ACPI_OEM_ID_SIZE);
    155     memcpy (Header->OemTableId, "AcpiExec", ACPI_OEM_TABLE_ID_SIZE);
    156     ACPI_COPY_NAMESEG (Header->AslCompilerId, "INTL");
    157     Header->AslCompilerRevision = ACPI_CA_VERSION;
    158 
    159     /* Set the checksum, must set to zero first */
    160 
    161     Header->Checksum = 0;
    162     Header->Checksum = (UINT8) -AcpiUtChecksum (
    163         (void *) Header, Header->Length);
    164 }
    165 
    166 
    167 /******************************************************************************
    168  *
    169  * FUNCTION:    AeBuildLocalTables
    170  *
    171  * PARAMETERS:  TableCount      - Number of tables on the command line
    172  *              ListHead        - List of actual tables from files
    173  *
    174  * RETURN:      Status
    175  *
    176  * DESCRIPTION: Build a complete ACPI table chain, with a local RSDP, XSDT,
    177  *              FADT, and several other test tables.
    178  *
    179  *****************************************************************************/
    180 
    181 ACPI_STATUS
    182 AeBuildLocalTables (
    183     ACPI_NEW_TABLE_DESC     *ListHead)
    184 {
    185     UINT32                  TableCount = 1;
    186     ACPI_PHYSICAL_ADDRESS   DsdtAddress = 0;
    187     UINT32                  XsdtSize;
    188     ACPI_NEW_TABLE_DESC     *NextTable;
    189     UINT32                  NextIndex;
    190     ACPI_TABLE_FADT         *ExternalFadt = NULL;
    191 
    192 
    193     /*
    194      * Update the table count. For the DSDT, it is not put into the XSDT.
    195      * For the FADT, this table is already accounted for since we usually
    196      * install a local FADT.
    197      */
    198     NextTable = ListHead;
    199     while (NextTable)
    200     {
    201         if (!ACPI_COMPARE_NAMESEG (NextTable->Table->Signature, ACPI_SIG_DSDT) &&
    202             !ACPI_COMPARE_NAMESEG (NextTable->Table->Signature, ACPI_SIG_FADT))
    203         {
    204             TableCount++;
    205         }
    206 
    207         NextTable = NextTable->Next;
    208     }
    209 
    210     XsdtSize = (((TableCount + 1) * sizeof (UINT64)) +
    211         sizeof (ACPI_TABLE_HEADER));
    212     if (AcpiGbl_LoadTestTables)
    213     {
    214         XsdtSize += BASE_XSDT_SIZE;
    215     }
    216 
    217     /* Build an XSDT */
    218 
    219     LocalXSDT = AcpiOsAllocate (XsdtSize);
    220     if (!LocalXSDT)
    221     {
    222         return (AE_NO_MEMORY);
    223     }
    224 
    225     memset (LocalXSDT, 0, XsdtSize);
    226     LocalXSDT->TableOffsetEntry[0] = ACPI_PTR_TO_PHYSADDR (&LocalFADT);
    227     NextIndex = 1;
    228 
    229     /*
    230      * Install the user tables. The DSDT must be installed in the FADT.
    231      * All other tables are installed directly into the XSDT.
    232      */
    233     NextTable = ListHead;
    234     while (NextTable)
    235     {
    236         /*
    237          * Incoming DSDT or FADT are special cases. All other tables are
    238          * just immediately installed into the XSDT.
    239          */
    240         if (ACPI_COMPARE_NAMESEG (NextTable->Table->Signature, ACPI_SIG_DSDT))
    241         {
    242             if (DsdtAddress)
    243             {
    244                 printf ("Already found a DSDT, only one allowed\n");
    245                 return (AE_ALREADY_EXISTS);
    246             }
    247 
    248             /* The incoming user table is a DSDT */
    249 
    250             DsdtAddress = ACPI_PTR_TO_PHYSADDR (NextTable->Table);
    251             DsdtToInstallOverride = NextTable->Table;
    252         }
    253         else if (ACPI_COMPARE_NAMESEG (NextTable->Table->Signature, ACPI_SIG_FADT))
    254         {
    255             ExternalFadt = ACPI_CAST_PTR (ACPI_TABLE_FADT, NextTable->Table);
    256             LocalXSDT->TableOffsetEntry[0] = ACPI_PTR_TO_PHYSADDR (NextTable->Table);
    257         }
    258         else
    259         {
    260             /* Install the table in the XSDT */
    261 
    262             LocalXSDT->TableOffsetEntry[NextIndex] =
    263                 ACPI_PTR_TO_PHYSADDR (NextTable->Table);
    264             NextIndex++;
    265         }
    266 
    267         NextTable = NextTable->Next;
    268     }
    269 
    270     /* Install the optional extra local tables */
    271 
    272     if (AcpiGbl_LoadTestTables)
    273     {
    274         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&LocalTEST);
    275         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&LocalBADTABLE);
    276 
    277         /* Install two SSDTs to test multiple table support */
    278 
    279         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&Ssdt1Code);
    280         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&Ssdt2Code);
    281 
    282         /* Install the OEM1 table to test LoadTable */
    283 
    284         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&Oem1Code);
    285 
    286         /* Install the OEMx table to test LoadTable */
    287 
    288         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&OemxCode);
    289 
    290          /* Install the ECDT table to test _REG */
    291 
    292         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&EcdtCode);
    293 
    294         /* Install two UEFIs to test multiple table support */
    295 
    296         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&Uefi1Code);
    297         LocalXSDT->TableOffsetEntry[NextIndex++] = ACPI_PTR_TO_PHYSADDR (&Uefi2Code);
    298     }
    299 
    300     /* Build an RSDP. Contains a valid XSDT only, no RSDT */
    301 
    302     memset (&LocalRSDP, 0, sizeof (ACPI_TABLE_RSDP));
    303     ACPI_MAKE_RSDP_SIG (LocalRSDP.Signature);
    304     memcpy (LocalRSDP.OemId, "Intel", 6);
    305 
    306     LocalRSDP.Revision = 2;
    307     LocalRSDP.XsdtPhysicalAddress = ACPI_PTR_TO_PHYSADDR (LocalXSDT);
    308     LocalRSDP.Length = sizeof (ACPI_TABLE_RSDP);
    309 
    310     /* Set checksums for both XSDT and RSDP */
    311 
    312     AeInitializeTableHeader ((void *) LocalXSDT, ACPI_SIG_XSDT, XsdtSize);
    313 
    314     LocalRSDP.Checksum = 0;
    315     LocalRSDP.Checksum = (UINT8) -AcpiUtChecksum (
    316         (void *) &LocalRSDP, ACPI_RSDP_CHECKSUM_LENGTH);
    317 
    318     if (!DsdtAddress)
    319     {
    320         /* Use the local DSDT because incoming table(s) are all SSDT(s) */
    321 
    322         DsdtAddress = ACPI_PTR_TO_PHYSADDR (LocalDsdtCode);
    323         DsdtToInstallOverride = ACPI_CAST_PTR (ACPI_TABLE_HEADER, LocalDsdtCode);
    324     }
    325 
    326     /*
    327      * Build an FADT. There are three options for the FADT:
    328      * 1) Incoming external FADT specified on the command line
    329      * 2) A "hardware reduced" local FADT
    330      * 3) A fully featured local FADT
    331      */
    332     memset (&LocalFADT, 0, sizeof (ACPI_TABLE_FADT));
    333 
    334     if (ExternalFadt)
    335     {
    336         /*
    337          * Use the external FADT, but we must update the DSDT/FACS
    338          * addresses as well as the checksum
    339          */
    340         ExternalFadt->Dsdt = (UINT32) DsdtAddress;
    341         if (!AcpiGbl_ReducedHardware)
    342         {
    343             ExternalFadt->Facs = ACPI_PTR_TO_PHYSADDR (&LocalFACS);
    344         }
    345 
    346         /*
    347          * If there room in the FADT for the XDsdt and XFacs 64-bit
    348          * pointers, use them.
    349          */
    350         if (ExternalFadt->Header.Length > ACPI_PTR_DIFF (
    351             &ExternalFadt->XDsdt, ExternalFadt))
    352         {
    353             ExternalFadt->Dsdt = 0;
    354             ExternalFadt->Facs = 0;
    355 
    356             ExternalFadt->XDsdt = DsdtAddress;
    357             if (!AcpiGbl_ReducedHardware)
    358             {
    359                 ExternalFadt->XFacs = ACPI_PTR_TO_PHYSADDR (&LocalFACS);
    360             }
    361         }
    362 
    363         /* Complete the external FADT with the checksum */
    364 
    365         ExternalFadt->Header.Checksum = 0;
    366         ExternalFadt->Header.Checksum = (UINT8) -AcpiUtChecksum (
    367             (void *) ExternalFadt, ExternalFadt->Header.Length);
    368     }
    369     else if (AcpiGbl_UseHwReducedFadt)
    370     {
    371         memcpy (&LocalFADT, HwReducedFadtCode, ACPI_FADT_V5_SIZE);
    372         LocalFADT.Dsdt = 0;
    373         LocalFADT.XDsdt = DsdtAddress;
    374     }
    375     else
    376     {
    377         /*
    378          * Build a local FADT so we can test the hardware/event init
    379          */
    380         LocalFADT.Header.Revision = 5;
    381 
    382         /* Setup FADT header and DSDT/FACS addresses */
    383 
    384         LocalFADT.Dsdt = 0;
    385         LocalFADT.Facs = 0;
    386 
    387         LocalFADT.XDsdt = DsdtAddress;
    388         LocalFADT.XFacs = ACPI_PTR_TO_PHYSADDR (&LocalFACS);
    389 
    390         /* Miscellaneous FADT fields */
    391 
    392         LocalFADT.Gpe0BlockLength = 0x20;
    393         LocalFADT.Gpe0Block = 0x00003210;
    394 
    395         LocalFADT.Gpe1BlockLength = 0x20;
    396         LocalFADT.Gpe1Block = 0x0000BA98;
    397         LocalFADT.Gpe1Base = 0x80;
    398 
    399         LocalFADT.Pm1EventLength = 4;
    400         LocalFADT.Pm1aEventBlock = 0x00001aaa;
    401         LocalFADT.Pm1bEventBlock = 0x00001bbb;
    402 
    403         LocalFADT.Pm1ControlLength = 2;
    404         LocalFADT.Pm1aControlBlock = 0xB0;
    405 
    406         LocalFADT.PmTimerLength = 4;
    407         LocalFADT.PmTimerBlock = 0xA0;
    408 
    409         LocalFADT.Pm2ControlBlock = 0xC0;
    410         LocalFADT.Pm2ControlLength = 1;
    411 
    412         /* Setup one example X-64 GAS field */
    413 
    414         LocalFADT.XPm1bEventBlock.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
    415         LocalFADT.XPm1bEventBlock.Address = LocalFADT.Pm1bEventBlock;
    416         LocalFADT.XPm1bEventBlock.BitWidth = (UINT8)
    417             ACPI_MUL_8 (LocalFADT.Pm1EventLength);
    418     }
    419 
    420     AeInitializeTableHeader ((void *) &LocalFADT,
    421         ACPI_SIG_FADT, sizeof (ACPI_TABLE_FADT));
    422 
    423     /* Build a FACS */
    424 
    425     memset (&LocalFACS, 0, sizeof (ACPI_TABLE_FACS));
    426     ACPI_COPY_NAMESEG (LocalFACS.Signature, ACPI_SIG_FACS);
    427 
    428     LocalFACS.Length = sizeof (ACPI_TABLE_FACS);
    429     LocalFACS.GlobalLock = 0x11AA0011;
    430 
    431     /* Build the optional local tables */
    432 
    433     if (AcpiGbl_LoadTestTables)
    434     {
    435         /*
    436          * Build a fake table [TEST] so that we make sure that the
    437          * ACPICA core ignores it
    438          */
    439         memset (&LocalTEST, 0, sizeof (ACPI_TABLE_HEADER));
    440         ACPI_COPY_NAMESEG (LocalTEST.Signature, "TEST");
    441 
    442         LocalTEST.Revision = 1;
    443         LocalTEST.Length = sizeof (ACPI_TABLE_HEADER);
    444 
    445         LocalTEST.Checksum = 0;
    446         LocalTEST.Checksum = (UINT8) -AcpiUtChecksum (
    447             (void *) &LocalTEST, LocalTEST.Length);
    448 
    449         /*
    450          * Build a fake table with a bad signature [BAD!] so that we make
    451          * sure that the ACPICA core ignores it
    452          */
    453         memset (&LocalBADTABLE, 0, sizeof (ACPI_TABLE_HEADER));
    454         ACPI_COPY_NAMESEG (LocalBADTABLE.Signature, "BAD!");
    455 
    456         LocalBADTABLE.Revision = 1;
    457         LocalBADTABLE.Length = sizeof (ACPI_TABLE_HEADER);
    458 
    459         LocalBADTABLE.Checksum = 0;
    460         LocalBADTABLE.Checksum = (UINT8) -AcpiUtChecksum (
    461             (void *) &LocalBADTABLE, LocalBADTABLE.Length);
    462     }
    463 
    464     return (AE_OK);
    465 }
    466 
    467 
    468 /******************************************************************************
    469  *
    470  * FUNCTION:    AeInstallTables
    471  *
    472  * PARAMETERS:  None
    473  *
    474  * RETURN:      Status
    475  *
    476  * DESCRIPTION: Install the various ACPI tables
    477  *
    478  *****************************************************************************/
    479 
    480 ACPI_STATUS
    481 AeInstallTables (
    482     void)
    483 {
    484     ACPI_STATUS             Status;
    485     ACPI_TABLE_HEADER       Header;
    486     ACPI_TABLE_HEADER       *Table;
    487     UINT32                  i;
    488 
    489 
    490     Status = AcpiInitializeTables (NULL, ACPI_MAX_INIT_TABLES, TRUE);
    491     ACPI_CHECK_OK (AcpiInitializeTables, Status);
    492 
    493     /*
    494      * The following code is prepared to test the deferred table
    495      * verification mechanism. When AcpiGbl_EnableTableValidation is set
    496      * to FALSE by default, AcpiReallocateRootTable() sets it back to TRUE
    497      * and triggers the deferred table verification mechanism accordingly.
    498      */
    499     (void) AcpiReallocateRootTable ();
    500 
    501     if (AcpiGbl_LoadTestTables)
    502     {
    503         /* Test multiple table/UEFI support. First, get the headers */
    504 
    505         Status = AcpiGetTableHeader (ACPI_SIG_UEFI, 1, &Header);
    506         ACPI_CHECK_OK (AcpiGetTableHeader, Status);
    507 
    508         Status = AcpiGetTableHeader (ACPI_SIG_UEFI, 2, &Header);
    509         ACPI_CHECK_OK (AcpiGetTableHeader, Status);
    510 
    511         Status = AcpiGetTableHeader (ACPI_SIG_UEFI, 3, &Header);
    512         ACPI_CHECK_STATUS (AcpiGetTableHeader, Status, AE_NOT_FOUND);
    513 
    514         /* Now get the actual tables */
    515 
    516         Status = AcpiGetTable (ACPI_SIG_UEFI, 1, &Table);
    517         ACPI_CHECK_OK (AcpiGetTable, Status);
    518 
    519         Status = AcpiGetTable (ACPI_SIG_UEFI, 2, &Table);
    520         ACPI_CHECK_OK (AcpiGetTable, Status);
    521 
    522         Status = AcpiGetTable (ACPI_SIG_UEFI, 3, &Table);
    523         ACPI_CHECK_STATUS (AcpiGetTable, Status, AE_NOT_FOUND);
    524     }
    525 
    526     /* Check that we can get all of the ACPI tables */
    527 
    528     for (i = 0; ; i++)
    529     {
    530         Status = AcpiGetTableByIndex (i, &Table);
    531         if ((Status == AE_BAD_PARAMETER) || !Table)
    532         {
    533             break;
    534         }
    535 
    536         ACPI_CHECK_OK (AcpiGetTableByIndex, Status);
    537     }
    538 
    539     return (AE_OK);
    540 }
    541 
    542 
    543 /******************************************************************************
    544  *
    545  * FUNCTION:    AeLoadTables
    546  *
    547  * PARAMETERS:  None
    548  *
    549  * RETURN:      Status
    550  *
    551  * DESCRIPTION: Load the definition block ACPI tables
    552  *
    553  *****************************************************************************/
    554 
    555 ACPI_STATUS
    556 AeLoadTables (
    557     void)
    558 {
    559     ACPI_STATUS             Status;
    560 
    561 
    562     Status = AcpiLoadTables ();
    563     ACPI_CHECK_OK (AcpiLoadTables, Status);
    564 
    565     /*
    566      * Test run-time control method installation. Do it twice to test code
    567      * for an existing name.
    568      */
    569     Status = AcpiInstallMethod (MethodCode);
    570     ACPI_CHECK_OK (AcpiInstallMethod, Status);
    571 
    572     Status = AcpiInstallMethod (MethodCode);
    573     ACPI_CHECK_OK (AcpiInstallMethod, Status);
    574 
    575     return (AE_OK);
    576 }
    577 
    578 
    579 /******************************************************************************
    580  *
    581  * FUNCTION:    AcpiOsGetRootPointer
    582  *
    583  * PARAMETERS:  Flags       - not used
    584  *              Address     - Where the root pointer is returned
    585  *
    586  * RETURN:      Status
    587  *
    588  * DESCRIPTION: Return a local RSDP, used to dynamically load tables via the
    589  *              standard ACPI mechanism.
    590  *
    591  *****************************************************************************/
    592 
    593 ACPI_PHYSICAL_ADDRESS
    594 AcpiOsGetRootPointer (
    595     void)
    596 {
    597 
    598     return (ACPI_PTR_TO_PHYSADDR (&LocalRSDP));
    599 }
    600