setpci(8) The PCI Utilities setpci(8)
NAME
setpci - configure PCI devices
SYNOPSIS
setpci [options] devices operations...
DESCRIPTION
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 config‐
uration space on some operating systems. Please see lspci(8) for details on access rights.
OPTIONS
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.
--version
Show setpci version. This option should be used stand-alone.
--help Show detailed help on available options. This option should be used stand-alone.
--dumpregs
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 fol‐
lowing 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 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.
-d [<vendor>]:[<device>]
Select devices with specified vendor and device ID. Both ID's are given in hexadecimal and may be omit‐
ted 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.
OPERATIONS
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 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 --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 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.
EXAMPLES
COMMAND
asks for the word-sized command register.
4.w is a numeric address of the same register.
COMMAND.l
asks for a 32-bit word starting at the location of the command register, i.e., the command and status
registers together.
VENDOR_ID+1.b
specifies the upper byte of the vendor ID register (remember, PCI is little-endian).
AUTHOR
The PCI Utilities are maintained by Martin Mares <[email protected]>.
pciutils-3.5.1 22 May 2016 setpci(8)
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