bios_smbios.c File Reference

System Management BIOS. More...

#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <gpxe/uaccess.h>
#include <gpxe/smbios.h>
#include <realmode.h>
#include <pnpbios.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
static int	bios_find_smbios (struct smbios *smbios)
	Find SMBIOS.
	PROVIDE_SMBIOS (pcbios, find_smbios, bios_find_smbios)

---

Detailed Description

System Management BIOS.

Definition in file bios_smbios.c.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static int bios_find_smbios

(

struct smbios *

smbios

)

[static]

Find SMBIOS.

Parameters:

smbios

SMBIOS entry point descriptor structure to fill in

Return values:

rc

Return status code

Definition at line 42 of file bios_smbios.c.

References smbios::address, BIOS_SEG, copy_from_real, smbios::count, DBG, ENODEV, smbios::len, smbios_entry::len, offset, phys_to_user(), and SMBIOS_SIGNATURE.

                                                      {
        union {
                struct smbios_entry entry;
                uint8_t bytes[256]; /* 256 is maximum length possible */
        } u;
        static unsigned int offset = 0;
        size_t len;
        unsigned int i;
        uint8_t sum;

        /* Try to find SMBIOS */
        for ( ; offset < 0x10000 ; offset += 0x10 ) {

                /* Read start of header and verify signature */
                copy_from_real ( &u.entry, BIOS_SEG, offset,
                                 sizeof ( u.entry ));
                if ( u.entry.signature != SMBIOS_SIGNATURE )
                        continue;

                /* Read whole header and verify checksum */
                len = u.entry.len;
                copy_from_real ( &u.bytes, BIOS_SEG, offset, len );
                for ( i = 0 , sum = 0 ; i < len ; i++ ) {
                        sum += u.bytes[i];
                }
                if ( sum != 0 ) {
                        DBG ( "SMBIOS at %04x:%04x has bad checksum %02x\n",
                              BIOS_SEG, offset, sum );
                        continue;
                }

                /* Fill result structure */
                DBG ( "Found SMBIOS v%d.%d entry point at %04x:%04x\n",
                      u.entry.major, u.entry.minor, BIOS_SEG, offset );
                smbios->address = phys_to_user ( u.entry.smbios_address );
                smbios->len = u.entry.smbios_len;
                smbios->count = u.entry.smbios_count;
                return 0;
        }

        DBG ( "No SMBIOS found\n" );
        return -ENODEV;
}

PROVIDE_SMBIOS	(	pcbios	,
		find_smbios	,
		bios_find_smbios
	)