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.
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
-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
Show setpci version. This option should be used stand-alone.
--help Show detailed help on available options. This option should be
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:
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
The behavior of the library is controlled by several named
parameters. This option allows 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.
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
Select devices with specified vendor and device ID. Both ID's
are given in hexadecimal and may be omitted or given as "*",
both meaning "any value".
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.
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-
There are several ways how to identity 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 sketch.
· 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
· 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 hexadecimal.
· 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.
· Finally, you should append a width specifier .B, .W, or .L to
choose how many bytes (1, 2, or 4) should be transferred. The
width can be omitted if you are referring to a register by its
name and the width of the register is well known.
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 together.
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
This page is part of the pciutils (PCI utilities) project.
Information about the project can be found at
⟨http://mj.ucw.cz/sw/pciutils/⟩. If you have a bug report for this
manual page, send it to email@example.com. This page was
obtained from the project's upstream Git repository
2016-12-10. If you discover any rendering problems in this HTML ver‐
sion of the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original man‐
ual page), send a mail to firstname.lastname@example.org
pciutils-3.4.0 14 September 2015 setpci(8)