PCICTL(8) | System Manager's Manual | PCICTL(8)

# NAME

`pcictl` — a program to manipulate the PCI bus

# SYNOPSIS

`pcictl` | pcibus command [arg ...]

# DESCRIPTION

`pcictl` allows a user or system administrator to access various resources on a PCI bus. The pcibus argument names a special file for the PCI bus device. If the file name is relative, it's interpreted relative to the /dev directory, so e.g. plain ‘`pci0`’ refers to /dev/pci0.

The following commands are available:

`list` [`-Nn`] [`-b` bus] [`-d` device] [`-f` function]
  List the devices in the PCI domain, either as names or, if `-n` is given, as numbers.

  If `-N` is given, the driver name for this PCI device will be listed if any driver is attached.

  Any locator not specified defaults to a wildcard, or may be explicitly wildcarded by specifying ‘`all`’, or ‘`any`’.

The remaining commands operate on a single PCI device, the `-d` argument is mandatory. If the bus is not specified, it defaults to the bus number of the pcibus. If the function is not specified, it defaults to 0.

`dump` [`-b` bus] `-d` device [`-f` function]
  Dump the PCI configuration space for the specified device.
`read` [`-b` bus] `-d` device [`-f` function] register
  Read the specified 32-bit aligned PCI configuration register and print it in hexadecimal to standard output.
`write` [`-b` bus] `-d` device [`-f` function] register value
  Write the specified value to the specified 32-bit aligned PCI configuration register.

# FILES

/dev/pci*
  PCI bus device nodes

# EXAMPLES

This shows all PCI devices on the system:

`pcictl pci0 list`

This shows all PCI devices on the system, including attached drivers:

`pcictl pci0 list -N`

# SEE ALSO

pci(3), pci(4), drvctl(8)

# HISTORY

The `pcictl` command first appeared in NetBSD 1.6.

# CAVEATS

`pcictl` `read` and `write` are dangerous commands that can damage hardware and panic the operating system. They are meant as a diagnostic tool for experiments or to debug device drivers. Do not use them as substitutes for a device driver!

January 25, 2026 | NetBSD 11.99