ACPIDUMP(8)

NAME
acpidump - dump ACPI tables

SYNOPSIS
acpidump
acpidump [-o dsdt_file_for_output]
acpidump [-f dsdt_file_for_input]

DESCRIPTION
The acpidump command analyzes ACPI tables in physical memory and dumps them to standard output. In addition, acpidump can disassemble some contents of the tables in AML (ACPI Machine Language) and dump them in ASL (ACPI Source Language).

ACPI tables have an notably essential data block called DSDT (Differentiated System Description Table), that includes information used on the kernel side such as detail information about PnP hardware, procedures for controlling a power management support and so on. acpidump can extract a DSDT data block from physical memory and store it into a DSDT data file, and also can generate an output in ASL from a given DSDT data file.

When acpidump is invoked with no option, it will search ACPI tables from physical memory via a special file /dev/mem and dump them. First, it searches Root System Description Pointer, that has a signature "RSD PTR ", and then gets RSDT (Root System Description Table), which includes a list of pointers to physical memory addresses for other tables. RSDT itself and all other tables linked from RSDT are generically called SDT (System Description Table) and their header has the common format which consists of items such as Signature, Length, Revision, Checksum, OEMID, OEM Table ID, OEM Revision, Creator ID and Creator Revision. acpidump dumps contents of these SDTs. For further information about formats of each table, see chapter 5: ACPI Software Programming Model, “Advanced Configuration and Power Interface Specification Revision 1.0b” from Intel/Microsoft/Toshiba.

There is always a pointer to a physical memory address in RSDT for FACP (Fixed ACPI Description Table). 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 location of ACPI registers. FACP also has a pointer to a physical memory address for DSDT, which includes information used on the kernel side such as PnP, power management support and so on. While the other tables are described in fixed format, DSDT consists of AML data which compiled from sources written in free formated ASL, description language for ACPI. When acpidump outputs DSDT, it disassembles the AML data and translates them into ASL.

OPTIONS
The following options are supported by acpidump:

-o dsdt_file_for_output
    Stores DSDT data block from physical memory into a file specified in dsdt_file_for_output in addition to behavior with no option.

-f dsdt_file_for_input
    Interprets AML data in DSDT from a file specified in dsdt_file_for_input and dumps them in ASL to standard output.

-h  Displays usage and exit.

EXAMPLES
This is an example to get a dump of SDTs and a DSDT data file simultaneously on a machine that supports ACPI BIOS.

    # acpidump -o foo.dsdt > foo.asl

BUGS
In the current implementation, acpidump doesn't dump any information of Firmware ACPI Control Structure (FACS) specified by a pointer in FACP.

FILES

/dev/mem

SEE ALSO
acpi(4), mem(4), acpiconf(8), amldb(8)

“Advanced Configuration and Power Interface Specification”
    Intel
    Microsoft
    Toshiba
    Revision 1.0b

<URL:http://www.teleport.com/~acpi/>

AUTHORS
Doug Rabson <dfr@FreeBSD.org> Mitsuru IWASAKI <iwasaki@FreeBSD.org> Yasuo YOKOYAMA <yokoyama@jp.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>, and Michael Lucas <mwlucas@blackhelicopters.org>.

HISTORY
The acpidump command appeared in FreeBSD 5.0.