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 sig‐
nature, usually an uppercase ASCII sequence sur‐
rounded 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 loca‐
tion is incremented 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 } -terminated 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 start‐
ing at their corresponding offset with unprintable
characters being replaced with space, and consecu‐
tive spaces being suppressed. This composed string
is stored in buffer up to the given maxlen bytes
(including trailing ‘\0’, and any trailing space
surpressed). If an error is encountered, i.e. try‐
ing 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 corre‐
sponds to the kernel virtual address addr.
BIOS_PADDRTOVADDR() Returns the kernel virtual address which corre‐
sponds to the effective physical address addr.
SMBIOStable If not NULL, points to a struct SMBIOS_table struc‐
ture containing information read from the System
Management BIOS table during system startup.
DMItable If not NULL, points to a struct DMI_table structure
containing information read from the Desktop Man‐
agement 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 reg‐
ister arguments to the function are supplied in
args.
PCIbios If not NULL, points to a struct bios32_SDentry
structure describing the PCI BIOS entrypoint which
was found during system startup.
BSD August 9, 2005 BSD
