CALL xxxxh:xxxxh - Intel BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. Upgrade
InstallCheck:	scan paragraph boundaries from 0F0000h to 0FFFFFh for signature
	  string "$IBU" (see #F0023)
SeeAlso: INT 15/AX=D042h/BL=00h
!!! IAL\PROCESSR\PPROBIOS.PDF page 60


Format of Intel BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. Upgrade header:
Offset	Size	Description	(Table F0023)
 00h  4 BYTEs	signature "$IBU"
 04h	BYTE	IBU specification version (currently 01h = 1.0)
 05h	BYTE	length of entire header structure in bytes (currently 17h)
 06h	BYTE	checksum (forces 8-bit sum of all header bytes to 00h)
 07h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	real-mode entry point address
 0Bh	WORD	offset of 16-bit protected mode entry point
 0Dh	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	segment base address of 16-bit protected-mode entry point
 11h	WORD	real-mode data segment address
 13h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	segment base address of 16-bit protected-mode data segment
Notes:	calls from 32-bit protected mode may be made to the 16-bit entry
	  point, but must ensure that any stack arguments are pushed as
	  16-bit values instead of 32-bit values
	the entry point uses standard C calling conventions to implement
	  functions prototyped as
		int far (*entrypoint)(int function, ...)