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NVRAM(4) | Device Drivers 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
nvram_load="YES"
DESCRIPTION¶
Thenvram
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
dd if=nvram.bin
of=/dev/nvram
SEE ALSO¶
dd(1)HISTORY¶
Thenvram
device driver first appeared in
FreeBSD 6.4.
AUTHORS¶
Thenvram
device driver was written by
Peter Wemm. This manual page was written by
Xin LI.February 8, 2010 | Debian |