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