_CA_PCI_Write_Config_Byte()

write individual bytes to the configuration space of a device

Synopsis:

#include <sys/pci.h>
int _CA_PCI_Write_Config_Byte( unsigned busnum,
                               unsigned devfuncnum,
                               unsigned offset,
                               unsigned cnt,
                               char *bufptr );

Description:

This function writes individual bytes to the configuration space of the specified device.

The arguments are as follows:

busnum

the bus number

devfuncnum

the device or function ID The device number is in bits 7 through 3, and the function number in bits 2 through 0.

offset

the register offset into the configuration space, in the range 0 through 255

cnt

the number of bytes to write

bufptr

a pointer to a buffer containing the data to be written into the configuration space

Returns:

PCI_SUCCESS

the device or function was found

PCI_BAD_REGISTER_NUMBER

an invalid offset register number was given

Classification:

Intel

Caveats:

When you use the _CA_PCI_... functions:

• Your program must be linked for privity level 1, and the process must be run by the superuser (root) or a setuid program that's owned by the superuser but started by a regular user. For more information on privity, see the cc -T option or the Linker PRIVILEGE option.
• The stack size must be less than 64K.

See also:

_CA_PCI_BIOS_Present(), _CA_PCI_Find_Class(), _CA_PCI_Find_Device(), _CA_PCI_GenerateSpecialCycle(), _CA_PCI_Read_Config_Byte(), _CA_PCI_Read_Config_DWord(), _CA_PCI_Read_Config_Word(), _CA_PCI_Write_Config_DWord(), _CA_PCI_Write_Config_Word()