Int1Ah AX = B10Bh(在PCI表面配置空間上，寫入Byte) -- BIOS Int1Ah

WRITE CONFIGURATION BYTE


Input:
AX = B10Bh
BH = bus number
BL = device/function number (bits 7-3 device, bits 2-0 function)
DI = register number (0000h-00FFh)
CL = byte to write
Return: 
CF clear if successful
CF set on error
AH = status (00h,87h) (see PCI BIOS v2.0 status codes)
EAX, EBX, ECX, and EDX may be modified
all other flags (except IF) may be modified
Notes:

this function may require up to 1024 byte of stack; it will not enable interrupts if they were disabled before making the call

the meanings of BL and BH on entry were exchanged between the initial drafts of the specification and final implementation