tbutils.c

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/******************************************************************************
 *
 * Module Name: tbutils   - table utilities
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbutils")

/* Local prototypes */
static void acpi_tb_fix_string(char *string, acpi_size length);

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
                 struct acpi_table_header *header);

static acpi_physical_address
acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_check_xsdt
 *
 * PARAMETERS:  address                    - Pointer to the XSDT
 *
 * RETURN:      status
 *      AE_OK - XSDT is okay
 *      AE_NO_MEMORY - can't map XSDT
 *      AE_INVALID_TABLE_LENGTH - invalid table length
 *      AE_NULL_ENTRY - XSDT has NULL entry
 *
 * DESCRIPTION: validate XSDT
******************************************************************************/

static acpi_status
acpi_tb_check_xsdt(acpi_physical_address address)
{
    struct acpi_table_header *table;
    u32 length;
    u64 xsdt_entry_address;
    u8 *table_entry;
    u32 table_count;
    int i;

    table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
    if (!table)
        return AE_NO_MEMORY;

    length = table->length;
    acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
    if (length < sizeof(struct acpi_table_header))
        return AE_INVALID_TABLE_LENGTH;

    table = acpi_os_map_memory(address, length);
    if (!table)
        return AE_NO_MEMORY;

    /* Calculate the number of tables described in XSDT */
    table_count =
        (u32) ((table->length -
        sizeof(struct acpi_table_header)) / sizeof(u64));
    table_entry =
        ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
    for (i = 0; i < table_count; i++) {
        ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry);
        if (!xsdt_entry_address) {
            /* XSDT has NULL entry */
            break;
        }
        table_entry += sizeof(u64);
    }
    acpi_os_unmap_memory(table, length);

    if (i < table_count)
        return AE_NULL_ENTRY;
    else
        return AE_OK;
}

#if (!ACPI_REDUCED_HARDWARE)
/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_initialize_facs
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
 *              for accessing the Global Lock and Firmware Waking Vector
 *
 ******************************************************************************/

acpi_status acpi_tb_initialize_facs(void)
{
    acpi_status status;

    /* If Hardware Reduced flag is set, there is no FACS */

    if (acpi_gbl_reduced_hardware) {
        acpi_gbl_FACS = NULL;
        return (AE_OK);
    }

    status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
                     ACPI_CAST_INDIRECT_PTR(struct
                                acpi_table_header,
                                &acpi_gbl_FACS));
    return status;
}
#endif              /* !ACPI_REDUCED_HARDWARE */

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_tables_loaded
 *
 * PARAMETERS:  None
 *
 * RETURN:      TRUE if required ACPI tables are loaded
 *
 * DESCRIPTION: Determine if the minimum required ACPI tables are present
 *              (FADT, FACS, DSDT)
 *
 ******************************************************************************/

u8 acpi_tb_tables_loaded(void)
{

    if (acpi_gbl_root_table_list.current_table_count >= 3) {
        return (TRUE);
    }

    return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_fix_string
 *
 * PARAMETERS:  string              - String to be repaired
 *              length              - Maximum length
 *
 * RETURN:      None
 *
 * DESCRIPTION: Replace every non-printable or non-ascii byte in the string
 *              with a question mark '?'.
 *
 ******************************************************************************/

static void acpi_tb_fix_string(char *string, acpi_size length)
{

    while (length && *string) {
        if (!ACPI_IS_PRINT(*string)) {
            *string = '?';
        }
        string++;
        length--;
    }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_cleanup_table_header
 *
 * PARAMETERS:  out_header          - Where the cleaned header is returned
 *              header              - Input ACPI table header
 *
 * RETURN:      Returns the cleaned header in out_header
 *
 * DESCRIPTION: Copy the table header and ensure that all "string" fields in
 *              the header consist of printable characters.
 *
 ******************************************************************************/

static void
acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
                 struct acpi_table_header *header)
{

    ACPI_MEMCPY(out_header, header, sizeof(struct acpi_table_header));

    acpi_tb_fix_string(out_header->signature, ACPI_NAME_SIZE);
    acpi_tb_fix_string(out_header->oem_id, ACPI_OEM_ID_SIZE);
    acpi_tb_fix_string(out_header->oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
    acpi_tb_fix_string(out_header->asl_compiler_id, ACPI_NAME_SIZE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_print_table_header
 *
 * PARAMETERS:  address             - Table physical address
 *              header              - Table header
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print an ACPI table header. Special cases for FACS and RSDP.
 *
 ******************************************************************************/

void
acpi_tb_print_table_header(acpi_physical_address address,
               struct acpi_table_header *header)
{
    struct acpi_table_header local_header;

    /*
     * The reason that the Address is cast to a void pointer is so that we
     * can use %p which will work properly on both 32-bit and 64-bit hosts.
     */
    if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_FACS)) {

        /* FACS only has signature and length fields */

        ACPI_INFO((AE_INFO, "%4.4s %p %05X",
               header->signature, ACPI_CAST_PTR(void, address),
               header->length));
    } else if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_RSDP)) {

        /* RSDP has no common fields */

        ACPI_MEMCPY(local_header.oem_id,
                ACPI_CAST_PTR(struct acpi_table_rsdp,
                      header)->oem_id, ACPI_OEM_ID_SIZE);
        acpi_tb_fix_string(local_header.oem_id, ACPI_OEM_ID_SIZE);

        ACPI_INFO((AE_INFO, "RSDP %p %05X (v%.2d %6.6s)",
               ACPI_CAST_PTR (void, address),
               (ACPI_CAST_PTR(struct acpi_table_rsdp, header)->
                revision >
                0) ? ACPI_CAST_PTR(struct acpi_table_rsdp,
                           header)->length : 20,
               ACPI_CAST_PTR(struct acpi_table_rsdp,
                     header)->revision,
               local_header.oem_id));
    } else {
        /* Standard ACPI table with full common header */

        acpi_tb_cleanup_table_header(&local_header, header);

        ACPI_INFO((AE_INFO,
               "%4.4s %p %05X (v%.2d %6.6s %8.8s %08X %4.4s %08X)",
               local_header.signature, ACPI_CAST_PTR(void, address),
               local_header.length, local_header.revision,
               local_header.oem_id, local_header.oem_table_id,
               local_header.oem_revision,
               local_header.asl_compiler_id,
               local_header.asl_compiler_revision));

    }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_checksum
 *
 * PARAMETERS:  table               - ACPI table to verify
 *              length              - Length of entire table
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
 *              exception on bad checksum.
 *
 ******************************************************************************/

acpi_status acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length)
{
    u8 checksum;

    /* Compute the checksum on the table */

    checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, table), length);

    /* Checksum ok? (should be zero) */

    if (checksum) {
        ACPI_BIOS_WARNING((AE_INFO,
                   "Incorrect checksum in table [%4.4s] - 0x%2.2X, "
                   "should be 0x%2.2X",
                   table->signature, table->checksum,
                   (u8)(table->checksum - checksum)));

#if (ACPI_CHECKSUM_ABORT)

        return (AE_BAD_CHECKSUM);
#endif
    }

    return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_checksum
 *
 * PARAMETERS:  buffer          - Pointer to memory region to be checked
 *              length          - Length of this memory region
 *
 * RETURN:      Checksum (u8)
 *
 * DESCRIPTION: Calculates circular checksum of memory region.
 *
 ******************************************************************************/

u8 acpi_tb_checksum(u8 *buffer, u32 length)
{
    u8 sum = 0;
    u8 *end = buffer + length;

    while (buffer < end) {
        sum = (u8) (sum + *(buffer++));
    }

    return sum;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_check_dsdt_header
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
 *              if the DSDT has been replaced from outside the OS and/or if
 *              the DSDT header has been corrupted.
 *
 ******************************************************************************/

void acpi_tb_check_dsdt_header(void)
{

    /* Compare original length and checksum to current values */

    if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
        acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
        ACPI_BIOS_ERROR((AE_INFO,
                 "The DSDT has been corrupted or replaced - "
                 "old, new headers below"));
        acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
        acpi_tb_print_table_header(0, acpi_gbl_DSDT);

        ACPI_ERROR((AE_INFO,
                "Please send DMI info to [email protected]\n"
                "If system does not work as expected, please boot with acpi=copy_dsdt"));

        /* Disable further error messages */

        acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
        acpi_gbl_original_dsdt_header.checksum =
            acpi_gbl_DSDT->checksum;
    }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_copy_dsdt
 *
 * PARAMETERS:  table_desc          - Installed table to copy
 *
 * RETURN:      None
 *
 * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
 *              Some very bad BIOSs are known to either corrupt the DSDT or
 *              install a new, bad DSDT. This copy works around the problem.
 *
 ******************************************************************************/

struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
{
    struct acpi_table_header *new_table;
    struct acpi_table_desc *table_desc;

    table_desc = &acpi_gbl_root_table_list.tables[table_index];

    new_table = ACPI_ALLOCATE(table_desc->length);
    if (!new_table) {
        ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
                table_desc->length));
        return (NULL);
    }

    ACPI_MEMCPY(new_table, table_desc->pointer, table_desc->length);
    acpi_tb_delete_table(table_desc);
    table_desc->pointer = new_table;
    table_desc->flags = ACPI_TABLE_ORIGIN_ALLOCATED;

    ACPI_INFO((AE_INFO,
           "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
           new_table->length));

    return (new_table);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_install_table
 *
 * PARAMETERS:  address                 - Physical address of DSDT or FACS
 *              signature               - Table signature, NULL if no need to
 *                                        match
 *              table_index             - Index into root table array
 *
 * RETURN:      None
 *
 * DESCRIPTION: Install an ACPI table into the global data structure. The
 *              table override mechanism is called to allow the host
 *              OS to replace any table before it is installed in the root
 *              table array.
 *
 ******************************************************************************/

void
acpi_tb_install_table(acpi_physical_address address,
              char *signature, u32 table_index)
{
    struct acpi_table_header *table;
    struct acpi_table_header *final_table;
    struct acpi_table_desc *table_desc;

    if (!address) {
        ACPI_ERROR((AE_INFO,
                "Null physical address for ACPI table [%s]",
                signature));
        return;
    }

    /* Map just the table header */

    table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
    if (!table) {
        ACPI_ERROR((AE_INFO,
                "Could not map memory for table [%s] at %p",
                signature, ACPI_CAST_PTR(void, address)));
        return;
    }

    /* If a particular signature is expected (DSDT/FACS), it must match */

    if (signature && !ACPI_COMPARE_NAME(table->signature, signature)) {
        ACPI_BIOS_ERROR((AE_INFO,
                 "Invalid signature 0x%X for ACPI table, expected [%s]",
                 *ACPI_CAST_PTR(u32, table->signature),
                 signature));
        goto unmap_and_exit;
    }

    /*
     * Initialize the table entry. Set the pointer to NULL, since the
     * table is not fully mapped at this time.
     */
    table_desc = &acpi_gbl_root_table_list.tables[table_index];

    table_desc->address = address;
    table_desc->pointer = NULL;
    table_desc->length = table->length;
    table_desc->flags = ACPI_TABLE_ORIGIN_MAPPED;
    ACPI_MOVE_32_TO_32(table_desc->signature.ascii, table->signature);

    /*
     * ACPI Table Override:
     *
     * Before we install the table, let the host OS override it with a new
     * one if desired. Any table within the RSDT/XSDT can be replaced,
     * including the DSDT which is pointed to by the FADT.
     *
     * NOTE: If the table is overridden, then final_table will contain a
     * mapped pointer to the full new table. If the table is not overridden,
     * or if there has been a physical override, then the table will be
     * fully mapped later (in verify table). In any case, we must
     * unmap the header that was mapped above.
     */
    final_table = acpi_tb_table_override(table, table_desc);
    if (!final_table) {
        final_table = table;    /* There was no override */
    }

    acpi_tb_print_table_header(table_desc->address, final_table);

    /* Set the global integer width (based upon revision of the DSDT) */

    if (table_index == ACPI_TABLE_INDEX_DSDT) {
        acpi_ut_set_integer_width(final_table->revision);
    }

    /*
     * If we have a physical override during this early loading of the ACPI
     * tables, unmap the table for now. It will be mapped again later when
     * it is actually used. This supports very early loading of ACPI tables,
     * before virtual memory is fully initialized and running within the
     * host OS. Note: A logical override has the ACPI_TABLE_ORIGIN_OVERRIDE
     * flag set and will not be deleted below.
     */
    if (final_table != table) {
        acpi_tb_delete_table(table_desc);
    }

      unmap_and_exit:

    /* Always unmap the table header that we mapped above */

    acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_get_root_table_entry
 *
 * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
 *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
 *
 * RETURN:      Physical address extracted from the root table
 *
 * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
 *              both 32-bit and 64-bit platforms
 *
 * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
 *              64-bit platforms.
 *
 ******************************************************************************/

static acpi_physical_address
acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
{
    u64 address64;

    /*
     * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
     * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
     */
    if (table_entry_size == sizeof(u32)) {
        /*
         * 32-bit platform, RSDT: Return 32-bit table entry
         * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
         */
        return ((acpi_physical_address)
            (*ACPI_CAST_PTR(u32, table_entry)));
    } else {
        /*
         * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
         * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
         *  return 64-bit
         */
        ACPI_MOVE_64_TO_64(&address64, table_entry);

#if ACPI_MACHINE_WIDTH == 32
        if (address64 > ACPI_UINT32_MAX) {

            /* Will truncate 64-bit address to 32 bits, issue warning */

            ACPI_BIOS_WARNING((AE_INFO,
                       "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
                       " truncating",
                       ACPI_FORMAT_UINT64(address64)));
        }
#endif
        return ((acpi_physical_address) (address64));
    }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_parse_root_table
 *
 * PARAMETERS:  rsdp                    - Pointer to the RSDP
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to parse the Root System Description
 *              Table (RSDT or XSDT)
 *
 * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
 *              be mapped and cannot be copied because it contains the actual
 *              memory location of the ACPI Global Lock.
 *
 ******************************************************************************/

acpi_status __init
acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
{
    struct acpi_table_rsdp *rsdp;
    u32 table_entry_size;
    u32 i;
    u32 table_count;
    struct acpi_table_header *table;
    acpi_physical_address address;
    acpi_physical_address uninitialized_var(rsdt_address);
    u32 length;
    u8 *table_entry;
    acpi_status status;

    ACPI_FUNCTION_TRACE(tb_parse_root_table);

    /*
     * Map the entire RSDP and extract the address of the RSDT or XSDT
     */
    rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
    if (!rsdp) {
        return_ACPI_STATUS(AE_NO_MEMORY);
    }

    acpi_tb_print_table_header(rsdp_address,
                   ACPI_CAST_PTR(struct acpi_table_header,
                         rsdp));

    /* Differentiate between RSDT and XSDT root tables */

    if (rsdp->revision > 1 && rsdp->xsdt_physical_address
            && !acpi_rsdt_forced) {
        /*
         * Root table is an XSDT (64-bit physical addresses). We must use the
         * XSDT if the revision is > 1 and the XSDT pointer is present, as per
         * the ACPI specification.
         */
        address = (acpi_physical_address) rsdp->xsdt_physical_address;
        table_entry_size = sizeof(u64);
        rsdt_address = (acpi_physical_address)
                    rsdp->rsdt_physical_address;
    } else {
        /* Root table is an RSDT (32-bit physical addresses) */

        address = (acpi_physical_address) rsdp->rsdt_physical_address;
        table_entry_size = sizeof(u32);
    }

    /*
     * It is not possible to map more than one entry in some environments,
     * so unmap the RSDP here before mapping other tables
     */
    acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));

    if (table_entry_size == sizeof(u64)) {
        if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
            /* XSDT has NULL entry, RSDT is used */
            address = rsdt_address;
            table_entry_size = sizeof(u32);
            ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
                    "using RSDT"));
        }
    }
    /* Map the RSDT/XSDT table header to get the full table length */

    table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
    if (!table) {
        return_ACPI_STATUS(AE_NO_MEMORY);
    }

    acpi_tb_print_table_header(address, table);

    /* Get the length of the full table, verify length and map entire table */

    length = table->length;
    acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));

    if (length < sizeof(struct acpi_table_header)) {
        ACPI_BIOS_ERROR((AE_INFO,
                 "Invalid table length 0x%X in RSDT/XSDT",
                 length));
        return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
    }

    table = acpi_os_map_memory(address, length);
    if (!table) {
        return_ACPI_STATUS(AE_NO_MEMORY);
    }

    /* Validate the root table checksum */

    status = acpi_tb_verify_checksum(table, length);
    if (ACPI_FAILURE(status)) {
        acpi_os_unmap_memory(table, length);
        return_ACPI_STATUS(status);
    }

    /* Calculate the number of tables described in the root table */

    table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
                table_entry_size);
    /*
     * First two entries in the table array are reserved for the DSDT
     * and FACS, which are not actually present in the RSDT/XSDT - they
     * come from the FADT
     */
    table_entry =
        ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
    acpi_gbl_root_table_list.current_table_count = 2;

    /*
     * Initialize the root table array from the RSDT/XSDT
     */
    for (i = 0; i < table_count; i++) {
        if (acpi_gbl_root_table_list.current_table_count >=
            acpi_gbl_root_table_list.max_table_count) {

            /* There is no more room in the root table array, attempt resize */

            status = acpi_tb_resize_root_table_list();
            if (ACPI_FAILURE(status)) {
                ACPI_WARNING((AE_INFO,
                          "Truncating %u table entries!",
                          (unsigned) (table_count -
                           (acpi_gbl_root_table_list.
                              current_table_count -
                              2))));
                break;
            }
        }

        /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */

        acpi_gbl_root_table_list.tables[acpi_gbl_root_table_list.
                        current_table_count].address =
            acpi_tb_get_root_table_entry(table_entry, table_entry_size);

        table_entry += table_entry_size;
        acpi_gbl_root_table_list.current_table_count++;
    }

    /*
     * It is not possible to map more than one entry in some environments,
     * so unmap the root table here before mapping other tables
     */
    acpi_os_unmap_memory(table, length);

    /*
     * Complete the initialization of the root table array by examining
     * the header of each table
     */
    for (i = 2; i < acpi_gbl_root_table_list.current_table_count; i++) {
        acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
                      address, NULL, i);

        /* Special case for FADT - get the DSDT and FACS */

        if (ACPI_COMPARE_NAME
            (&acpi_gbl_root_table_list.tables[i].signature,
             ACPI_SIG_FADT)) {
            acpi_tb_parse_fadt(i);
        }
    }

    return_ACPI_STATUS(AE_OK);
}