pci_read_config8()

Read a byte from the configuration space of a device

Synopsis:

#include <hw/pci.h>

int pci_read_config8( unsigned bus,
                      unsigned dev_func,
                      unsigned offset,
                      unsigned count,
                      char* buff );

Arguments:

bus

The bus number.

dev_func

The name of the device or function.

offset

The register offset into the configuration space, in the range [0...255].

count

The number of bytes to read.

buff

A pointer to a buffer where the requested bytes are placed.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The pci_read_config8() function reads the specified number of bytes from the configuration space of the given device or function.

---

You must successfully call pci_attach() before calling any of the other PCI functions.

---

Returns:

PCI_BAD_REGISTER_NUMBER

An invalid register offset was given.

PCI_BUFFER_TOO_SMALL

The PCI BIOS server reads only 100 bytes at a time; count is too large.

PCI_SUCCESS

The device or function was found.

-1

You haven't called pci_attach(), or the call to it failed.

Classification:

QNX Neutrino

See also:

pci_attach(), pci_attach_device(), pci_detach(), pci_detach_device(), pci_find_class(), pci_find_device(), pci_present(), pci_read_config(), pci_read_config16(), pci_read_config32(), pci_rescan_bus(), pci_write_config(), pci_write_config8(), pci_write_config16(), pci_write_config32()