setpci(8) — Linux manual page


setpci(8)                   The PCI Utilities                  setpci(8)

NAME         top

       setpci - configure PCI devices

SYNOPSIS         top

       setpci [options] devices operations...

DESCRIPTION         top

       setpci is a utility for querying and configuring PCI devices.

       All numbers are entered in hexadecimal notation.

       Root privileges are necessary for almost all operations,
       excluding reads of the standard header of the configuration space
       on some operating systems.  Please see lspci(8) for details on
       access rights.

OPTIONS         top

   General options
       -v     Tells setpci to be verbose and display detailed
              information about configuration space accesses.

       -f     Tells setpci not to complain when there's nothing to do
              (when no devices are selected).  This option is intended
              for use in widely-distributed configuration scripts where
              it's uncertain whether the device in question is present
              in the machine or not.

       -D     `Demo mode' -- don't write anything to the configuration
              registers.  It's useful to try setpci -vD to verify that
              your complex sequence of setpci operations does what you
              think it should do.

       -r     Avoids bus scan if each operation selects a specific
              device (uses the -s selector with specific domain, bus,
              slot, and function). This is faster, but if the device
              does not exist, it fails instead of matching an empty set
              of devices.

              Show setpci version. This option should be used stand-

       --help Show detailed help on available options. This option
              should be used stand-alone.

              Show a list of all known PCI registers and capabilities.
              This option should be used stand-alone.

   PCI access options
       The PCI utilities use the PCI library to talk to PCI devices (see
       pcilib(7) for details). You can use the following options to
       influence its behavior:

       -A <method>
              The library supports a variety of methods to access the
              PCI hardware.  By default, it uses the first access method
              available, but you can use this option to override this
              decision. See -A help for a list of available methods and
              their descriptions.

       -O <param>=<value>
              The behavior of the library is controlled by several named
              parameters.  This option allows one to set the value of
              any of the parameters. Use -O help for a list of known
              parameters and their default values.

       -H1    Use direct hardware access via Intel configuration
              mechanism 1.  (This is a shorthand for -A intel-conf1.)

       -H2    Use direct hardware access via Intel configuration
              mechanism 2.  (This is a shorthand for -A intel-conf2.)

       -G     Increase debug level of the library.


       Before each sequence of operations you need to select which
       devices you wish that operation to affect.

       -s [[[[<domain>]:]<bus>]:][<slot>][.[<func>]]
              Consider only devices in the specified domain (in case
              your machine has several host bridges, they can either
              share a common bus number space or each of them can
              address a PCI domain of its own; domains are numbered from
              0 to ffff), bus (0 to ff), slot (0 to 1f) and function (0
              to 7).  Each component of the device address can be
              omitted or set to "*", both meaning "any value". All
              numbers are hexadecimal.  E.g., "0:" means all devices on
              bus 0, "0" means all functions of device 0 on any bus,
              "0.3" selects third function of device 0 on all buses and
              ".4" matches only the fourth function of each device.

       -d [<vendor>]:[<device>][:<class>[:<prog-if>]]
              Select devices with specified vendor, device, class ID,
              and programming interface.  The ID's are given in
              hexadecimal and may be omitted or given as "*", both
              meaning "any value". The class ID can contain "x"
              characters which stand for "any digit".

       When -s and -d are combined, only devices that match both
       criteria are selected. When multiple options of the same kind are
       specified, the rightmost one overrides the others.

OPERATIONS         top

       There are two kinds of operations: reads and writes. To read a
       register, just specify its name. Writes have the form
       name=value,value... where each value is either a hexadecimal
       number or an expression of type data:mask where both data and
       mask are hexadecimal numbers. In the latter case, only the bits
       corresponding to binary ones in the mask are changed
       (technically, this is a read-modify-write operation).

       There are several ways to identify a register:

       •      Tell its address in hexadecimal.

       •      Spell its name. Setpci knows the names of all registers in
              the standard configuration headers. Use `setpci
              --dumpregs' to get the complete list.  See PCI bus
              specifications for the precise meaning of these registers
              or consult header.h or /usr/include/pci/pci.h for a brief

       •      If the register is a part of a PCI capability, you can
              specify the name of the capability to get the address of
              its first register. See the names starting with `CAP_' or
              `ECAP_' in the --dumpregs output.

       •      If the name of the capability is not known to setpci, you
              can refer to it by its number in the form CAPid or ECAPid,
              where id is the numeric identifier of the capability in

       •      Each of the previous formats can be followed by +offset to
              add an offset (a hex number) to the address. This feature
              can be useful for addressing of registers living within a
              capability, or to modify parts of standard registers.

       •      To choose how many bytes (1, 2, or 4) should be
              transferred, you should append a width specifier .B, .W,
              or .L. The width can be omitted if you are referring to a
              register by its name and the width of the register is well

       •      Finally, if a capability exists multiple times you can
              choose which one to target using @number. Indexing starts
              at 0.

       All names of registers and width specifiers are case-insensitive.

              asks for the word-sized command register.

       4.w    is a numeric address of the same register.

              asks for a 32-bit word starting at the location of the
              command register, i.e., the command and status registers

              specifies the upper byte of the vendor ID register
              (remember, PCI is little-endian).

              corresponds to the second word of the power management

              asks for the first 32-bit word of the extended capability
              with ID 0x108.

SEE ALSO         top

       lspci(8), pcilib(7)

AUTHOR         top

       The PCI Utilities are maintained by Martin Mares <>.

COLOPHON         top

       This page is part of the pciutils (PCI utilities) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for
       this manual page, send it to  This
       page was obtained from the project's upstream Git repository
       ⟨git://⟩ on
       2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-08.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
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       manual page), send a mail to

pciutils-3.10.0                01 May 2023                     setpci(8)

Pages that refer to this page: proc(5)pcilib(7)lspci(8)