Category: expansion bus BIOSes

INT 15 - Intel System Management Bus - 16-BIT PROTECTED-MODE CONNECT

	AX = 53B0h
	BH = 03h
	CX = 6941h ('iA')
Return: CF clear if successful
	    AX = SMBus 16-bit code segment (real mode base address)
	    BX = offset of entry point into SMBus BIOS Interface
	    CX = SMBus 16-bit data segment (real mode base address)
	    SI = code segment length in bytes
	    DI = data segment length in bytes
	CF set if error
	    AH = error code (01h,02h,0Ah,86h) (see #00484)
	    AL = sub-error code if error code is 02h (see #00485)
Desc:	connect to SMBus interface; once connected, all SMBus calls are made
	  to the supplied entry point instead of INT 15 (with registers
	  identical to those described here for INT 15)
Notes:	before calling the entry point, two descriptors must be initialized
	  in the GDT or LDT.  They must be consecutive and be in the order of
	  code, then data.  At the time	of the call, the descriptors must be
	  valid and have CPL=0.
	the code descriptor must be ring-0 privilege
	this function is only supported in INT 15 mode
SeeAlso: AX=53B0h/BH=01h,AX=53B0h/BH=02h,AX=53B0h/BH=04h,AX=53B0h/BH=05h