Int 1A Fn B18D  - Pci Bios V2.0c+ - Write Configuration Dword (32-bit)     [X]

   AX = B18Dh
   BH = bus number
   BL = device/function number (bits 7-3 device, bits 2-0 function)
   DI = register number (multiple of 4 less than 0100h)
   ECX = dword to write

Return: as for AX=B10Dh

Note:  the meanings of BL and BH on return were exchanged between the initial
     drafts of the specification and final implementation

See Also: AX=B10Dh,AX=B18Bh,AX=B18Ch