pci_read_config()

Read from the configuration space of a PCI device

Synopsis:

#include <hw/pci.h>

int pci_read_config( void* handle,
                     unsigned offset,
                     unsigned count,
                     size_t size,
                     void* buff );

Arguments:

handle: The handle returned by pci_attach_device().
offset: The offset into the configuration space where you want to read from.
count: The number of objects that you want to read.
size: The size of each object.
buff: A pointer to a buffer where the function can store the objects that it reads.

Library:

libc

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

The pci_read_config() function reads count objects of the specified size into buff at the given offset from the configuration space of the PCI device specified by handle. For the details of the configuration space, see the _pci_config_regs structure in <hw/pci.h>.

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: The offset is invalid.
PCI_BUFFER_TOO_SMALL: The PCI BIOS server reads only 100 bytes at a time; size is too large.
PCI_DEVICE_NOT_FOUND: The handle is invalid.
PCI_SUCCESS: Success.
-1: You haven't called pci_attach(), or the call to it failed.

Examples:

See pci_read_config16().

Classification:

QNX Neutrino

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