CALL xxxxh:xxxxh - BIOS32 Service Directory InstallCheck: scan paragraph boundaries E000h to FFFFh for signature string "_32_", followed by a valid header structure (see #F0021) Notes: a 32-bit-code alternate PCI 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. entry point may be found (if supported) by requesting the entry point for the API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. with identifier "$PCI" an alternate entry point for INT 1A/AH=B4h may be found (if supported) by requesting the entry point for the API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. with identifier "$ACF" other known identifiers are "$WDS" and "MPTN" SeeAlso: INT 1A/AX=B100h Format of BIOS32 Service Directory header structure: Offset Size Description (Table F0021) 00h 4 BYTEs signature "_32_" 04h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. physical address of BSD entry point (see #F0022) 08h BYTE header structure version number (currently 00h) 09h BYTE header structure length in paragraphs (currently 01h) 0Ah BYTE checksum (8-bit sum of all bytes in structure, including this one, should equal zero) 0Bh 5 BYTEs reserved (0) (Table F0022) Call BIOS32 Service Directory entry point with: EBX = function 00000000h get service entry point EAX = service identifier 46434124h ("FCA$") Plug-and-Play Auto-Configuration 49435024h ("ICP$") PCI BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. 4E54504Dh ("NTPM") ??? MPTN [PhoenixBIOS4 Rev. 6.0] 54435724h ("SDW$") ??? WDS$ [PhoenixBIOS4 Rev. 6.0] Return: AL = status 00h successful EBX = base address of handler's code seg ECX = size of code segment EDX = offset of handler in code seg 80h unknown service identifier else Return: AL = 81h invalid function Notes: the BSD handler assumes that it is running in a 32-bit code segment the returned entry points for PCI 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. and Auto-Config must be called with the same registers as the real-mode INT 1Ah interface, including the value B1h or B4h in AH (AMIAmerican Megatrends, Inc.(American Megatrends, Inc.) A hardware, software and firmware company founded in 1985. 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. v1.00.05.AX1 returns the same entry point for both interfaces and uses AH to distinguish which API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. is desired) some references indicate that only BL is used for the function number, though at least one implementation actually checks the entire EBX register; for maximum compatibility, the upper 24 bits of EBX should be cleared when calling the entry point SeeAlso: #F0021