ACPIDUMP(8)             FreeBSD System Manager's Manual            ACPIDUMP(8)

NAME
     acpidump - dump ACPI tables and ASL

SYNOPSIS
     acpidump [-d] [-t] [-h] [-v] [-f dsdt_input] [-o dsdt_output]

DESCRIPTION
     The acpidump utility analyzes ACPI tables in physical memory and can dump
     them to a file.  In addition, acpidump can call iasl(8) to disassemble
     AML (ACPI Machine Language) found in these tables and dump them as ASL
     (ACPI Source Language) to stdout.

     ACPI tables have an essential data block (the DSDT, Differentiated System
     Description Table) that includes information used on the kernel side such
     as detailed information about PnP hardware, procedures for controlling
     power management support, and so on.  The acpidump utility can extract
     the DSDT data block from physical memory and store it into an output file
     and optionally also disassemble it.  If any Secondary System Description
     Table (SSDT) entries exist, they will also be included in the output file
     and disassembly.

     When acpidump is invoked without the -f option, it will read ACPI tables
     from physical memory via /dev/mem.  First it searches for the RSDP (Root
     System Description Pointer), which has the signature "RSD PTR ", and then
     gets the RSDT (Root System Description Table), which includes a list of
     pointers to physical memory addresses for other tables.  The RSDT itself
     and all other tables linked from RSDT are generically called SDTs (System
     Description Tables) and their header has a common format which consists
     of items such as Signature, Length, Revision, Checksum, OEMID, OEM Table
     ID, OEM Revision, Creator ID and Creator Revision.  When invoked with the
     -t flag, the acpidump utility dumps contents of the following tables:

           BERT
           DMAR
           DSDT
           ECDT
           EINJ
           ERST
           FACS
           FADT
           HEST
           HPET
           LPIT
           MADT
           MCFG
           NFIT
           RSD PTR
           RSDT
           SLIT
           SRAT
           TCPA
           TPM2
           WDDT

     The RSDT contains a pointer to the physical memory address of the FACP
     (Fixed ACPI Description Table).  The FACP defines static system
     information about power management support (ACPI Hardware Register
     Implementation) such as interrupt mode (INT_MODEL), SCI interrupt number,
     SMI command port (SMI_CMD) and the location of ACPI registers.  The FACP
     also has a pointer to a physical memory address for the DSDT.  While the
     other tables are fixed format, the DSDT consists of free-formatted AML
     data.

OPTIONS
     The following options are supported by acpidump:

     -d      Disassemble the DSDT into ASL using iasl(8) and print the results
             to stdout.

     -t      Dump the contents of the various fixed tables listed above.

     -h      Displays usage and exit.

     -v      Enable verbose messages.

     -f dsdt_input
             Load the DSDT from the specified file instead of physical memory.
             Since only the DSDT is stored in the file, the -t flag may not be
             used with this option.

     -o dsdt_output
             Store the DSDT data block from physical memory into the specified
             file.

FILES
     /dev/mem

EXAMPLES
     If a developer requests a copy of your ASL, please use the following
     command to dump all tables and compress the result.

           # acpidump -dt | gzip -c9 > my_computer.asl.gz

     This example dumps the DSDT from physical memory to foo.dsdt.  It also
     prints the contents of various system tables and disassembles the AML
     contained in the DSDT to stdout, redirecting the output to foo.asl.

           # acpidump -t -d -o foo.dsdt > foo.asl

     This example reads a DSDT file and disassembles it to stdout.  Verbose
     messages are enabled.

           # acpidump -v -d -f foo.dsdt

SEE ALSO
     acpi(4), mem(4), acpiconf(8), acpidb(8), iasl(8)

HISTORY
     The acpidump utility first appeared in FreeBSD 5.0 and was rewritten to
     use iasl(8) for FreeBSD 5.2.

AUTHORS
     Doug Rabson <dfr@FreeBSD.org>
     Mitsuru IWASAKI <iwasaki@FreeBSD.org>
     Yasuo YOKOYAMA <yokoyama@jp.FreeBSD.org>
     Nate Lawson <njl@FreeBSD.org>

     Some contributions made by Chitoshi Ohsawa <ohsawa@catv1.ccn-net.ne.jp>,
     Takayasu IWANASHI <takayasu@wendy.a.perfect-liberty.or.jp>, Yoshihiko
     SARUMARU <mistral@imasy.or.jp>, Hiroki Sato <hrs@FreeBSD.org>, Michael
     Lucas <mwlucas@blackhelicopters.org> and Michael Smith
     <msmith@FreeBSD.org>.

BUGS
     The current implementation does not dump the BOOT structure or other
     miscellaneous tables.

FreeBSD 13.1-RELEASE-p6          June 29, 2020         FreeBSD 13.1-RELEASE-p6