NAME

pciconf — diagnostic utility for the PCI bus

SYNOPSIS

pciconf

-l [ -bcevV][ device]

pciconf

-a device

pciconf

-r [ -b | -h] device addr[ : addr2]

pciconf

-w [ -b | -h] device addr value

DESCRIPTION

The pciconf utility provides a command line interface to functionality provided by the pci(4) ioctl(2) interface. As such, some of the functions are only available to users with write access to /dev/pci, normally only the super-user.

With the -l option, pciconf lists PCI devices in the following format:

foo0@pci0:0:4:0: class=0x010000 card=0x00000000 chip=0x000f1000 rev=0x01 hdr=0x00 
bar0@pci0:0:5:0: class=0x000100 card=0x00000000 chip=0x88c15333 rev=0x00 hdr=0x00 
none0@pci0:0:6:0: class=0x020000 card=0x00000000 chip=0x802910ec rev=0x00 hdr=0x00

The first column gives the driver name, unit number, and selector . If there is no driver attached to the PCI device in question, the driver name will be “none”. Unit numbers for detached devices start at zero and are incremented for each detached device that is encountered. The selector is in a form which may directly be used for the other forms of the command. The second column is the class code, with the class byte printed as two hex digits, followed by the sub-class and the interface bytes. The third column gives the contents of the subvendorid register, introduced in revision 2.1 of the PCI standard. Note that it will be 0 for older cards. The field consists of the card ID in the upper half and the card vendor ID in the lower half of the value.

The fourth column contains the chip device ID, which identifies the chip this card is based on. It consists of two fields, identifying the chip and its vendor, as above. The fifth column prints the chip's revision. The sixth column describes the header type. Currently assigned header types include 0 for most devices, 1 for PCI to PCI bridges, and 2 for PCI to CardBus bridges. If the most significant bit of the header type register is set for function 0 of a PCI device, it is a multi-function device, which contains several (similar or independent) functions on one chip.

If the -b option is supplied, pciconf will list any base address registers (BARs) that are assigned resources for each device. Each BAR will be enumerated via a line in the following format:

    bar   [10] = type Memory, range 32, base 0xda060000, size 131072, enabled

The first value after the “ bar” prefix in the square brackets is the offset of the BAR in config space in hexadecimal. The type of a BAR is one of “Memory”, “Prefetchable Memory”, or “I/O Port”. The range indicates the maximum address the BAR decodes. The base and size indicate the start and length of the BAR's address window, respectively. Finally, the last flag indicates if the BAR is enabled or disabled.

If the -c option is supplied, pciconf will list any capabilities supported by each device. Each capability is enumerated via a line in the following format:

    cap 10[40] = PCI-Express 1 root port

The first value after the “ cap” prefix is the capability ID in hexadecimal. The second value in the square brackets is the offset of the capability in config space in hexadecimal. The format of the text after the equals sign is capability-specific.

Each extended capability is enumerated via a line in a similar format:

ecap 0002[100] = VC 1 max VC0

The first value after the “ ecap” prefix is the extended capability ID in hexadecimal. The second value in the square brackets is the offset of the extended capability in config space in hexadecimal. The format of the text after the equals sign is capability-specific.

If the -e option is supplied, pciconf will list any errors reported for this device in standard PCI error registers. Errors are checked for in the PCI status register, the PCI-express device status register, and the Advanced Error Reporting status registers.

If the -v option is supplied, pciconf will attempt to load the vendor/device information database, and print vendor, device, class and subclass identification strings for each device.

If the -V option is supplied, pciconf will list any vital product data (VPD) provided by each device. Each VPD keyword is enumerated via a line in the following format:

    VPD ro PN  = '110114640C0     '

The first string after the “ VPD” prefix indicates if the keyword is read-only “ro” or read-write “rw”. The second string provides the keyword name. The text after the the equals sign lists the value of the keyword which is usually an ASCII string.

If the optional device argument is given with the -l flag, pciconf will only list details about a single device instead of all devices.

All invocations of pciconf except for -l require a device. The device can be identified either by a device name if the device is attached to a driver or by a selector. Selectors identify a PCI device by its address in PCI config space and can take one of the following forms:

• pcidomain: bus: device: function
• pcibus: device: function
• pcibus: device

In the case of an abridged form, omitted selector components are assumed to be 0. An optional leading device name followed by @ and an optional final colon will be ignored; this is so that the first column in the output of pciconf -l can be used without modification. All numbers are base 10.

With the -a flag, pciconf determines whether any driver has been assigned to the device identified by selector. An exit status of zero indicates that the device has a driver; non-zero indicates that it does not.

The -r option reads a configuration space register at byte offset addr of device selector and prints out its value in hexadecimal. The optional second address addr2 specifies a range to read. The -w option writes the value into a configuration space register at byte offset addr of device selector. For both operations, the flags -b and -h select the width of the operation; -b indicates a byte operation, and -h indicates a halfword (two-byte) operation. The default is to read or write a longword (four bytes).

ENVIRONMENT

The PCI vendor/device information database is normally read from /usr/share/misc/pci_vendors. This path can be overridden by setting the environment variable PCICONF_VENDOR_DATABASE.

SEE ALSO

ioctl(2), devinfo(8), kldload(8)

HISTORY

The pciconf utility appeared first in FreeBSD 2.2. The -a option was added for PCI KLD support in FreeBSD 3.0.

AUTHORS

The pciconf utility was written by Stefan Esser and Garrett Wollman.

BUGS

The -b and -h options are implemented in pciconf, but not in the underlying ioctl(2).

It might be useful to give non-root users access to the -a and -r options. But only root will be able to execute a kldload to provide the device with a driver KLD, and reading of configuration space registers may cause a failure in badly designed PCI chips.