Category: expansion bus BIOSes

INT 15 - Intel System Management Bus - 32-BIT PROTECTED-MODE CONNECT

	AX = 53B0h
	BH = 04h
	CX = 6941h ('iA')
Return: CF clear if successful
	    AX = SMBus 32-bit code segment (real mode base address)
	    EBX = offset of entry point into SMBus BIOS Interface
	    CX = SMBus 16-bit code segment (real mode base address)
	    DX = SMBus 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
	  32-bit code, 16-bit code, then data.	At the time of the call, the
	  descriptors must be valid and have CPL=0.
	the code descriptors must be ring-0 privilege
	this function is supported only in INT 15 mode
SeeAlso: AX=53B0h/BH=01h,AX=53B0h/BH=02h,AX=53B0h/BH=03h,AX=53B0h/BH=05h