PCI Driver - sysfunc 62
                -----------------------

  bl=0 - get PCI version
	OUT: AL=minor, AH=major
  bl=1 - get last bus
	OUT: AL=last bus in system
  bl=2 - get PCI access mechanism
	OUT: AL=1 or 2

  bl=4,5,6 - read configuration register (byte,word,dword)
	IN: bus in bl 
	    device+func in ch (dddddfff)
	    register address in cl 
                word-aligned for word registers (bl=5)
                dword-aligned for dword registers (bl=6)
        OUT: register contents in AL/AX/EAX

  bl=8,9,10 - write configuration register (byte,word,dword)
	IN: bus in bl 
	    device+func in ch (dddddfff)
	    register address in cl
                word-aligned for word registers (bl=9)
                dword-aligned for dword registers (bl=10)
            value in DL/DX/EDX
	OUT: 0 if ok, -1 if err


                How to scan system for PCI devices
                ----------------------------------

  loop bus from 0 to lastbus
    loop devfn from 0 to 255
      begin
        mov bl,6
        mov bh,bus
        mov ch,devfn
	mov cl,0     ; register adress
	mov eax,62
	int 0x40
        cmp ax,0
	je  next
	cmp ax,0xffff
	je  next
	
	; we've found a device
	; now: EAX = (deviceID<<16)+vendorID
next:
      end

                Standard PCI registers
                ----------------------


   addr  type  name 

   0	 word vendorID 
   2	 word deviceID 
   4	 word command_reg 
   6     word status_reg 
   8	 byte revisionID 
   9	 byte progIF 
   10    byte subclass 
   11	 byte classcode 
   12	 byte cacheline_size 
   13	 byte latency 
   14    byte header_type
   15	 byte BIST
   16    header-type specific

header_type values:
   0     nonbridge
   1     bridge
   2     cardbus

nonbridge device registers:

   16 	 dword base_adress0
   20	 dword base_address1
   24	 dword base_address2
   28	 dword base_address3
   32	 dword base_address4
   36	 dword base_address5
   40	 dword CardBus_CIS
   44	 word  subsystem_vendorID
   46	 word  subsystem_deviceID
   48	 dword expansion_ROM
   50	 byte  cap_ptr
   51	 byte  reserved1[3]
   54	 dword reserved2[1]
   58	 byte  interrupt_line
   59	 byte  interrupt_pin
   60	 byte  min_grant
   61	 byte  max_latency
   62	 dword device_specific[48]

bridge device registers:

   16 	 dword base_adress0
   20	 dword base_address1
   24	 byte  primary_bus
   25	 byte  secondary_bus
   26	 byte  subordinate_bus
   27	 byte  secondary_latency
   28	 byte  IO_base_low
   29	 byte  IO_limit_low
   30	 word  secondary_status
   32	 word  memory_base_low
   34	 word  memory_limit_low
   36	 word  prefetch_base_low
   38	 word  prefetch_limit_low
   40	 dword prefetch_base_high
   44	 dword prefetch_limit_high
   48	 word  IO_base_high
   50	 word  IO_limit_high
   52	 dword reserved2[1]
   56	 dword expansion_ROM
   60    byte  interrupt_line
   61	 byte  interrupt_pin
   62	 word  bridge_control
   64	 dword device_specific[48]

cardbus device registers:

   16	 dword ExCa_base
   20	 byte  cap_ptr
   21	 byte  reserved05
   22	 word  secondary_status
   24	 byte  PCI_bus
   25	 byte  CardBus_bus
   26	 byte  subordinate_bus
   27	 byte  latency_timer
   28	 dword memory_base0
   32	 dword memory_limit0
   36	 dword memory_base1
   40	 dword memory_limit1
   44	 word  IObase_0low
   46	 word  IObase_0high
   48	 word  IOlimit_0low
   50	 word  IOlimit_0high
   52	 word  IObase_1low 
   54	 word  IObase_1high
   56	 word  IOlimit_1low
   58	 word  IOlimit_1high
   60	 byte  interrupt_line
   61	 byte  interrupt_pin
   62	 word  bridge_control
   64	 word  subsystem_vendorID
   66	 word  subsystem_deviceID
   68	 dword legacy_baseaddr
   72	 dword cardbus_reserved[14]
  128	 dword vendor_specific[32]


                classcode & subclass
                --------------------

 classcode   subclass    device class
    1           *        Disk
    1           0        SCSI
    1           1        IDE
    1           2        Floppy
    1           3        IPI
    1           4        RAID

    2           *        Network
    2           0        Ethernet
    2           1        Token Ring
    2           2        FDDI
    2           3        ATM

    3           *        Display
    3           0        VGA
    3           1        SVGA
    3           2        XGA

    4           *        Multimedia
    4           0        video
    4           1        audio

    5           *        Memory
    5           0        RAM
    5           1        Flash memory

    6           *        Bridge
    6           0        CPU/PCI
    6           1        PCI/ISA
    6           2        PCI/EISA
    6           3        PCI/MCA
    6           4        PCI/PCI
    6           5        PCI/PCMCIA
    6           6        PCI/NuBus
    6           7        PCI/CardBus

    7           *        Communication
    7           0        serial
    7           1        parallel
    
    8           *        System peripheral
    8           0        PIC
    8           1        DMAC
    8           2        timer
    8           3        RTC
     
    9           *        Input
    9           0        keyboard
    9           1        digitizer
    9           2        mouse
   
    10          *        Docking station
    10          0        generic
    
    11          *        CPU
    11          0        386
    11          1        486
    11          2        Pentium
    11          3        P6
    11         0x10      Alpha
    11         0x40      coproc

    12          *        SerialBus
    12          0        Firewire
    12          1        ACCESS.bus
    12          2        SSA
    12          3        USB
    12          4        FiberChannel