nvram(4) [netbsd man page]

NVRAM(4)						   BSD Kernel Interfaces Manual 						  NVRAM(4)

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.

BSD
								 February 8, 2010							       BSD

nvram(8)						      System Manager's Manual							  nvram(8)

NAME

       nvram - manipulate firmware NVRAM variables

SYNOPSIS

       nvram [ -p ] [ -f filename ] [ -d name ] [ -c ] [ name [= value ]] ...

DESCRIPTION

       The  nvram command allows manipulation of firmware NVRAM variables.  It can be used to get or set a variable.  It can also be used to print
       all of the variables or set a list of variables from a file.  Changes to NVRAM variables are only saved by clean restart or shutdown.

       In principle, name can be any string.  In practice, not all strings will be accepted.  New World  machines  can	create	new  variables	as
       desired.  Some variables require administrator privilege to get or set.

       The  given  value  must match the data type required for name.  Binary data can be set using the %xx notation, where xx is the hex value of
       the byte.  The type for new variables is always binary data.

OPTIONS

       -d name
	      Deletes the named firmware variable.

       -f filename
	      Set firmware variables from a text file.	The file must be a list of "name value" statements.  The first space on each line is taken
	      to be the separator between "name" and "value".  If the last character of a line is , the value extends to the next line.

       -x     Use  XML	format	for reading and writing variables.  This option must be used before the -p or -f options, since arguments are pro-
	      cessed in order.

       -c     Delete all of the firmware variables.

       -p     Print all of the firmware variables.

EXAMPLES

	      example% nvram boot-args="-s rd=*hd:10"

       Set the boot-args variable to "-s rd=*hd:10".  This would specify single user mode with the root device in hard drive partition 10.

	      example% nvram my-variable="String One%00String Two%00%00"

       Create a new variable, my-variable, containing a list of two C-strings that is terminated by a NUL.

	      example% nvram -d my-variable

       Deletes the variable named my-variable.

								 October 28, 2003							  nvram(8)