tbfadt.c

acpi tools for linux include acpiexec and acpixtract

    /*
     * Validate the FADT checksum before we copy the table. Ignore
     * checksum error as we want to try to get the DSDT and FACS.
     */
    (void) AcpiTbVerifyChecksum (Table, Length);

    /* Obtain a local copy of the FADT in common ACPI 2.0+ format */

    AcpiTbCreateLocalFadt (Table, Length);

    /* All done with the real FADT, unmap it */

    AcpiOsUnmapMemory (Table, Length);

    /* Obtain the DSDT and FACS tables via their addresses within the FADT */

    AcpiTbInstallTable ((ACPI_PHYSICAL_ADDRESS) AcpiGbl_FADT.XDsdt,
        Flags, ACPI_SIG_DSDT, ACPI_TABLE_INDEX_DSDT);

    AcpiTbInstallTable ((ACPI_PHYSICAL_ADDRESS) AcpiGbl_FADT.XFacs,
        Flags, ACPI_SIG_FACS, ACPI_TABLE_INDEX_FACS);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiTbCreateLocalFadt
 *
 * PARAMETERS:  Table               - Pointer to BIOS FADT
 *              Length              - Length of the table
 *
 * RETURN:      None
 *
 * DESCRIPTION: Get a local copy of the FADT and convert it to a common format.
 *              Performs validation on some important FADT fields.
 *
 * NOTE:        We create a local copy of the FADT regardless of the version.
 *
 ******************************************************************************/

void
AcpiTbCreateLocalFadt (
    ACPI_TABLE_HEADER       *Table,
    UINT32                  Length)
{

    /*
     * Check if the FADT is larger than the largest table that we expect
     * (the ACPI 2.0/3.0 version). If so, truncate the table, and issue
     * a warning.
     */
    if (Length > sizeof (ACPI_TABLE_FADT))
    {
        ACPI_WARNING ((AE_INFO,
            "FADT (revision %u) is longer than ACPI 2.0 version, truncating length 0x%X to 0x%X",
            Table->Revision, Length, sizeof (ACPI_TABLE_FADT)));
    }

    /* Clear the entire local FADT */

    ACPI_MEMSET (&AcpiGbl_FADT, 0, sizeof (ACPI_TABLE_FADT));

    /* Copy the original FADT, up to sizeof (ACPI_TABLE_FADT) */

    ACPI_MEMCPY (&AcpiGbl_FADT, Table,
        ACPI_MIN (Length, sizeof (ACPI_TABLE_FADT)));

    /*
     * 1) Convert the local copy of the FADT to the common internal format
     * 2) Validate some of the important values within the FADT
     */
    AcpiTbConvertFadt ();
    AcpiTbValidateFadt ();
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiTbConvertFadt
 *
 * PARAMETERS:  None, uses AcpiGbl_FADT
 *
 * RETURN:      None
 *
 * DESCRIPTION: Converts all versions of the FADT to a common internal format.
 *              Expand all 32-bit addresses to 64-bit.
 *
 * NOTE:        AcpiGbl_FADT must be of size (ACPI_TABLE_FADT),
 *              and must contain a copy of the actual FADT.
 *
 * ACPICA will use the "X" fields of the FADT for all addresses.
 *
 * "X" fields are optional extensions to the original V1.0 fields. Even if
 * they are present in the structure, they can be optionally not used by
 * setting them to zero. Therefore, we must selectively expand V1.0 fields
 * if the corresponding X field is zero.
 *
 * For ACPI 1.0 FADTs, all address fields are expanded to the corresponding
 * "X" fields.
 *
 * For ACPI 2.0 FADTs, any "X" fields that are NULL are filled in by
 * expanding the corresponding ACPI 1.0 field.
 *
 ******************************************************************************/

static void
AcpiTbConvertFadt (
    void)
{
    UINT8                       Pm1RegisterLength;
    ACPI_GENERIC_ADDRESS        *Target;
    ACPI_NATIVE_UINT            i;


    /* Update the local FADT table header length */

    AcpiGbl_FADT.Header.Length = sizeof (ACPI_TABLE_FADT);

    /* Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary */

    if (!AcpiGbl_FADT.XFacs)
    {
        AcpiGbl_FADT.XFacs = (UINT64) AcpiGbl_FADT.Facs;
    }

    if (!AcpiGbl_FADT.XDsdt)
    {
        AcpiGbl_FADT.XDsdt = (UINT64) AcpiGbl_FADT.Dsdt;
    }

    /*
     * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
     * should be zero are indeed zero. This will workaround BIOSs that
     * inadvertently place values in these fields.
     *
     * The ACPI 1.0 reserved fields that will be zeroed are the bytes located at
     * offset 45, 55, 95, and the word located at offset 109, 110.
     */
    if (AcpiGbl_FADT.Header.Revision < 3)
    {
        AcpiGbl_FADT.PreferredProfile = 0;
        AcpiGbl_FADT.PstateControl = 0;
        AcpiGbl_FADT.CstControl = 0;
        AcpiGbl_FADT.BootFlags = 0;
    }

    /*
     * Expand the ACPI 1.0 32-bit V1.0 addresses to the ACPI 2.0 64-bit "X"
     * generic address structures as necessary.
     */
    for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++)
    {
        Target = ACPI_ADD_PTR (
            ACPI_GENERIC_ADDRESS, &AcpiGbl_FADT, FadtInfoTable[i].Target);

        /* Expand only if the X target is null */

        if (!Target->Address)
        {
            AcpiTbInitGenericAddress (Target,
                *ACPI_ADD_PTR (UINT8, &AcpiGbl_FADT, FadtInfoTable[i].Length),
                (UINT64) *ACPI_ADD_PTR (UINT32, &AcpiGbl_FADT, FadtInfoTable[i].Source));
        }
    }

    /*
     * Calculate separate GAS structs for the PM1 Enable registers.
     * These addresses do not appear (directly) in the FADT, so it is
     * useful to calculate them once, here.
     *
     * The PM event blocks are split into two register blocks, first is the
     * PM Status Register block, followed immediately by the PM Enable Register
     * block. Each is of length (Pm1EventLength/2)
     */
    Pm1RegisterLength = (UINT8) ACPI_DIV_2 (AcpiGbl_FADT.Pm1EventLength);

    /* The PM1A register block is required */

    AcpiTbInitGenericAddress (&AcpiGbl_XPm1aEnable, Pm1RegisterLength,
        (AcpiGbl_FADT.XPm1aEventBlock.Address + Pm1RegisterLength));

    /* The PM1B register block is optional, ignore if not present */

    if (AcpiGbl_FADT.XPm1bEventBlock.Address)
    {
        AcpiTbInitGenericAddress (&AcpiGbl_XPm1bEnable, Pm1RegisterLength,
            (AcpiGbl_FADT.XPm1bEventBlock.Address + Pm1RegisterLength));
    }
}


/******************************************************************************
 *
 * FUNCTION:    AcpiTbValidateFadt
 *
 * PARAMETERS:  Table           - Pointer to the FADT to be validated
 *
 * RETURN:      None
 *
 * DESCRIPTION: Validate various important fields within the FADT. If a problem
 *              is found, issue a message, but no status is returned.
 *              Used by both the table manager and the disassembler.
 *
 * Possible additional checks:
 * (AcpiGbl_FADT.Pm1EventLength >= 4)
 * (AcpiGbl_FADT.Pm1ControlLength >= 2)
 * (AcpiGbl_FADT.PmTimerLength >= 4)
 * Gpe block lengths must be multiple of 2
 *
 ******************************************************************************/

static void
AcpiTbValidateFadt (
    void)
{
    UINT32                  *Address32;
    ACPI_GENERIC_ADDRESS    *Address64;
    UINT8                   Length;
    ACPI_NATIVE_UINT        i;


    /* Examine all of the 64-bit extended address fields (X fields) */

    for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++)
    {
        /* Generate pointers to the 32-bit and 64-bit addresses and get the length */

        Address64 = ACPI_ADD_PTR (ACPI_GENERIC_ADDRESS, &AcpiGbl_FADT, FadtInfoTable[i].Target);
        Address32 = ACPI_ADD_PTR (UINT32, &AcpiGbl_FADT, FadtInfoTable[i].Source);
        Length = *ACPI_ADD_PTR (UINT8, &AcpiGbl_FADT, FadtInfoTable[i].Length);

        if (FadtInfoTable[i].Type & ACPI_FADT_REQUIRED)
        {
            /*
             * Field is required (PM1aEvent, PM1aControl, PmTimer).
             * Both the address and length must be non-zero.
             */
            if (!Address64->Address || !Length)
            {
                ACPI_ERROR ((AE_INFO,
                    "Required field \"%s\" has zero address and/or length: %8.8X%8.8X/%X",
                    FadtInfoTable[i].Name, ACPI_FORMAT_UINT64 (Address64->Address), Length));
            }
        }
        else if (FadtInfoTable[i].Type & ACPI_FADT_SEPARATE_LENGTH)
        {
            /*
             * Field is optional (PM2Control, GPE0, GPE1) AND has its own
             * length field. If present, both the address and length must be valid.
             */
            if ((Address64->Address && !Length) || (!Address64->Address && Length))
            {
                ACPI_WARNING ((AE_INFO,
                    "Optional field \"%s\" has zero address or length: %8.8X%8.8X/%X",
                    FadtInfoTable[i].Name, ACPI_FORMAT_UINT64 (Address64->Address), Length));
            }
        }

        /* If both 32- and 64-bit addresses are valid (non-zero), they must match */

        if (Address64->Address && *Address32 &&
           (Address64->Address != (UINT64) *Address32))
        {
            ACPI_ERROR ((AE_INFO,
                "32/64X address mismatch in \"%s\": [%8.8X] [%8.8X%8.8X], using 64X",
                FadtInfoTable[i].Name, *Address32, ACPI_FORMAT_UINT64 (Address64->Address)));
        }
    }
}