pcitool.rta is an INtime utility which displays information about the PCI devices in the local system. It runs in one of two modes:

Immediate mode: commands are provided on the command line which are executed at once.

Interactive: a prompt is displayes and the user can type commands in the tool.

The command format is the same in each mode.

Usage:

Immediate mode:

pcitool cmd [args..]

Interactive mode:

pcitool

 where cmd is one of:
  read  <options> <device> offset [count] -- read configuration data
  write <options> <device> offset value   -- write configuration data
  find  deviceID [vendorID]               -- locate a device by ID(s)
  class classID                           -- locate device(s) by class ID(s)
  header <device>                         -- display a device header
  bus                                     -- display bus and bridge info
  scan [info|addr|all]                    -- scan the PCI bus
       (with bus/irq|with address|toggle 'all' option)
  irq                                     -- show interrupt assignment info
  msi                                     -- show MSI info
  msix                                    -- show MSI-X info
  cfg                                     -- show devices in .CFG file format
  mcfg                                    -- dump MCFG record information
  rth                                     -- detect RTH support
  dump                                    -- dump PCIBUS device scan list
  method [standard|legacy|pcie|auto|check]-- show/change PCI access method
  exit|quit                               -- leave the utility

  help                                    -- print this message

The <options> field can be 'byte', 'word' or 'dword' and sets the word size
for the read and write operations.
(count defaults to 1 and vendorID defaults to 0x8086)
'device' is the PCI address (default 0) where 'device' is
         of the form [bus:]dev[.func]
For example:
  pci header 2:0.1 - reads the header from device 0 on bus 2, function 1
  pci write 6.1 4 0x1f - writes to device 6, function 1 (on bus 0)
  pci read dword 7 0 0 - reads the first dword from device 7 on bus 0;