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.


Note:
  • You must successfully call pci_attach() before calling any of the other PCI functions.
  • The pci_read_config*() functions can return inconsistent data if another process is extensively using the PCI bus.

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.

Examples:

See pci_attach_device().

Classification:

QNX Neutrino

Safety:
Cancellation point Yes
Interrupt handler No
Signal handler Yes
Thread Yes

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()