NAME

       nvram — non-volatile RAM

SYNOPSIS

       To compile this driver into the kernel, place the following line in your kernel configuration file:

             device nvram

       Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

             nvram_load="YES"

DESCRIPTION

       The nvram driver provides access to BIOS configuration NVRAM on i386 and amd64 systems.

       PC motherboard uses a small non-volatile memory to store BIOS settings which is usually part of its clock
       chip  and sometimes referred as “CMOS SRAM”.  This driver exposes bytes 14 through 128 of the NVRAM, or a
       total of 114 bytes, at offset zero of the device file /dev/nvram.

       This driver is useful for cloning machines that shares the same hardware configuration and need same BIOS
       setting tweaks.

IMPLEMENTATION NOTES

       The BIOS NVRAM's bytes 16 through 31 are checksummed at byte 32.  This driver  does  not  take  care  for
       these checksums.

EXAMPLES

       Backup existing BIOS NVRAM to nvram.bin:

             dd if=/dev/nvram of=nvram.bin

       Restore BIOS NVRAM from nvram.bin:

             dd if=nvram.bin of=/dev/nvram

SEE ALSO

       dd(1)

HISTORY

       The nvram device driver first appeared in FreeBSD 6.4.

AUTHORS

       The nvram device driver was written by Peter Wemm.  This manual page was written by Xin LI.

Debian                                          February 8, 2010                                        NVRAM(4)