I have found a field in DSDT table where I want to modify from here http://www.ztex.de/misc/c2ctl.e.html Generally, I want to modify the _PSS field about the processor so that I can have more frequency levels available in the CPUfreq driver interface. I try to use this command to dissemble the DSDT table from my Desktop(Linux2.6.29,Intel CORE 2):

 cat /proc/acpi/dsdt > dsdt.aml 
 iasl -d dsdt.aml

Then I have a file dsdt.dsl as following(very long, so I just show the beginning of the file):

    /*
     * Intel ACPI Component Architecture
     * AML Disassembler version 20090123
     *
     * Disassembly of dsdt.aml, Mon May  6 20:41:40 2013
     *
     *
     * Original Table Header:
     *     Signature        "DSDT"
     *     Length           0x00003794 (14228)
     *     Revision         0x01 **** ACPI 1.0, no 64-bit math support
     *     Checksum         0x46
     *     OEM ID           "DELL"
     *     OEM Table ID     "dt_ex"
     *     OEM Revision     0x00001000 (4096)
     *     Compiler ID      "INTL"
     *     Compiler Version 0x20050624 (537200164)
     */
    DefinitionBlock ("dsdt.aml", "DSDT", 1, "DELL", "dt_ex", 0x00001000)
    {
        Method (DBIN, 0, NotSerialized)
        {
            Noop
        }

        Scope (\)
        {
            Device (_SB.VBTN)
...................

But I can not find the _PSS field as shown in the website I have given above. I do not know why? I am sure the current cpufreq driver shows 4 frequency levels available. So at least there should be something in the table showing this..right? Has anybody here played with the DSDT table before? Thanks,