BIOS(9) 						   BSD Kernel Developer's Manual						   BIOS(9)

NAME

     bios_sigsearch, bios32_SDlookup, bios32, bios_oem_strings -- interact with PC BIOS

SYNOPSIS

     #include <sys/param.h>
     #include <vm/vm.h>
     #include <vm/pmap.h>
     #include <machine/param.h>
     #include <machine/pmap.h>
     #include <machine/pc/bios.h>

     u_int32_t
     bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs);

     int
     bios32_SDlookup(struct bios32_SDentry *ent);

     int
     bios32(struct bios_regs *br, u_int offset, u_short segment);

     BIOS_PADDRTOVADDR(addr);

     BIOS_VADDRTOPADDR(addr);

     extern struct bios32_SDentry PCIbios;
     extern struct SMBIOS_table SMBIOStable;
     extern struct DMI_table DMItable;

     int
     bios_oem_strings(struct bios_oem *oem, u_char *buffer, size_t maxlen);

     struct bios_oem_signature {
	     char * anchor;	     /* search anchor string in BIOS memory */
	     size_t offset;	     /* offset from anchor (may be negative) */
	     size_t totlen;	     /* total length of BIOS string to copy */
     };
     struct bios_oem_range {
	     u_int from;	     /* shouldn't be below 0xe0000 */
	     u_int to;		     /* shouldn't be above 0xfffff */
     };
     struct bios_oem {
	     struct bios_oem_range range;
	     struct bios_oem_signature signature[];
     };

DESCRIPTION

     These functions provide a general-purpose interface for dealing with the BIOS functions and data encountered on x86 PC-architecture systems.

     bios_sigsearch()	   Searches the BIOS address space for a service signature, usually an uppercase ASCII sequence surrounded by underscores.
			   The search begins at start, or at the beginning of the BIOS if start is zero.  siglen bytes of the BIOS image and sig
			   are compared at sigofs bytes offset from the current location.  If no match is found, the current location is incre-
			   mented by paralen bytes and the search repeated.  If the signature is found, its effective physical address is
			   returned.  If no signature is found, zero is returned.

     bios_oem_strings()    Searches a given BIOS memory range for one or more strings, and composes a printable concatenation of those found.  The
			   routine expects a structure describing the BIOS address range (within 0xe0000 - 0xfffff), and a { NULL, 0, 0 } -termi-
			   nated array of bios_oem_signature structures which define the anchor string, an offset from the beginning of the match
			   (which may be negative), and totlen number of bytes to be collected from BIOS memory starting at that offset.
			   Unmatched anchors are ignored, whereas matches are copied from BIOS memory starting at their corresponding offset with
			   unprintable characters being replaced with space, and consecutive spaces being suppressed.  This composed string is
			   stored in buffer up to the given maxlen bytes (including trailing '', and any trailing space surpressed).	If an
			   error is encountered, i.e. trying to read out of said BIOS range, other invalid input, or buffer overflow, a negative
			   integer is returned, otherwise the length of the composed string is returned.  In particular, a return value of 0 means
			   that none of the given anchor strings were found in the specified BIOS memory range.

     BIOS_VADDRTOPADDR()   Returns the effective physical address which corresponds to the kernel virtual address addr.

     BIOS_PADDRTOVADDR()   Returns the kernel virtual address which corresponds to the effective physical address addr.

     SMBIOStable	   If not NULL, points to a struct SMBIOS_table structure containing information read from the System Management BIOS ta-
			   ble during system startup.

     DMItable		   If not NULL, points to a struct DMI_table structure containing information read from the Desktop Management Interface
			   parameter table during system startup.

BIOS32
     At system startup, the BIOS is scanned for the BIOS32 Service Directory (part of the PCI specification), and the existence of the directory
     is recorded.  This can then be used to locate other services.

     bios32_SDlookup()	   Attempts to locate the BIOS32 service matching the 4-byte identifier passed in the ident field of the ent argument.

     bios32()		   Calls a bios32 function.  This presumes that the function is capable of working within the kernel segment (normally the
			   case).  The virtual address of the entrypoint is supplied in entry and the register arguments to the function are sup-
			   plied in args.

     PCIbios		   If not NULL, points to a struct bios32_SDentry structure describing the PCI BIOS entrypoint which was found during sys-
			   tem startup.

BSD
								  August 9, 2005							       BSD