PCITWEAK(1) General Commands Manual PCITWEAK(1)NAME
pcitweak - read/write PCI config space
SYNOPSIS
pcitweak -l
pcitweak -r PCI-ID [-b|-h] offset
pcitweak -w PCI-ID [-b|-h] offset value
DESCRIPTION
Pcitweak is a utility that can be used to examine or change registers in the PCI configuration space. On most platfoms pcitweak can only
be run by the root user.
OPTIONS -l Probe the PCI buses and print a line for each detected device. Each line contains the bus location (bus:device:function), chip
vendor/device, card (subsystem) vendor/card, revision, class and header type. All values printed are in hexadecimal.
-r PCI-ID
Read the PCI configuration space register at offset for the PCI device at bus location PCI-ID. PCI-ID should be given in the form
bus:device:function, with each value in hexadecimal. By default, a 32-bit register is read.
-w PCI-ID
Write value to the PCI configuration space register at offset for the PCI device at bus location PCI-ID. PCI-ID should be given in
the form bus:device:function, with each value in hexadecimal. By default, a 32-bit register is written.
-b Read or write an 8-bit value (byte).
-h Read or write a 16-bit value (halfword).
SEE ALSO scanpci(1)AUTHORS
David Dawes (dawes@xfree86.org).
XFree86 Version Version 4.3.0 PCITWEAK(1)
Check Out this Related Man Page
PCI(3) BSD Library Functions Manual PCI(3)NAME
pci -- library interface for PCI bus access
LIBRARY
PCI Bus Access Library (libpci, -lpci)
SYNOPSIS
#include <pci.h>
int
pcibus_conf_read(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t *valp);
int
pcibus_conf_write(int pcifd, u_int bus, u_int dev, u_int func, u_int reg, pcireg_t val);
int
pcidev_conf_read(int devfd, u_int reg, pcireg_t *valp);
int
pcidev_conf_write(int devfd, u_int reg, pcireg_t val);
char *
pci_findvendor(pcireg_t id_reg);
void
pci_devinfo(pcireg_t id_reg, pcireg_t class_reg, char *devinfo, size_t len);
void
pci_conf_print(int pcifd, u_int bus, u_int dev, u_int func);
DESCRIPTION
The pci library provides support for accessing the PCI bus by user programs.
These functions are available in the libpci library. Programs should be linked with -lpci.
CONFIGURATION SPACE FUNCTIONS
The following functions are used to access PCI configuration space:
pcibus_conf_read()
Access the PCI configuration register reg on the device located at bus, dev, func, and place the result in *valp. pcifd must be an
open file descriptor to a PCI bus within the target PCI domain.
pcibus_conf_write()
Write the value specified by val into the PCI configuration register reg on the device located at bus, dev, func. pcifd must be an
open file descriptor to a PCI bus within the target PCI domain.
pcidev_conf_read()
Access the PCI configuration register reg on the device associated with the open file descriptor devfd and place the result in *valp.
pcidev_conf_write()
Write the value specified by val into the PCI configuration register reg on the device associated with the open file descriptor devfd.
MISCELLANEOUS FUNCTIONS
The following miscellaneous functions are available:
pci_findvendor()
Return an ASCII description of the PCI vendor in the PCI ID register id_reg.
pci_devinfo()
Return an ASCII description of the PCI vendor, PCI product, and PCI class specified by the PCI ID register id_reg and PCI class ID reg-
ister class_reg. The description is placed into the buffer pointed to by devinfo; the size of that buffer is specified in len.
pci_conf_print()
Print the PCI configuration information for the device located at bus, dev, func. pcifd must be an open file descriptor to a PCI bus
within the target PCI domain.
RETURN VALUES
The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), and pcidev_conf_write() functions return 0 on success and -1 on failure.
The pci_findvendor() function returns NULL if the PCI vendor description cannot be found.
SEE ALSO pci(4)HISTORY
The pcibus_conf_read(), pcibus_conf_write(), pcidev_conf_read(), pcidev_conf_write(), pci_findvendor(), pci_devinfo(), and pci_conf_print()
functions first appeared in NetBSD 1.6.
BSD April 24, 2004 BSD