I tested by manually setting the BIOS to my preference, of a SLES11 box running on VMware, booted into the OS, ran
rebooted and manually factory defaulted the BIOS, booted back into the OS, and ran
dd if=/dev/nvram of=nvram.saved
Upon rebooting and checking the BIOS on startup, I was delighted to find that my preferential settings had in fact overwritten the defaults, effectively allowing for BIOS "revision" from within the OS using the known good configuration generated by the first dd command.
dd of=/dev/nvram if=nvram.saved
However, the vmware BIOS is a generic virtual BIOS utility, and even though this virtual test (so as to not brick my hardware!) was successful, subsequent tests on IBM hardware ThinkCentre result in failure. Following the same process as above, the factory default BIOS settings still remain. It is interesting though, that when I perform the hexdump using
the output matches the hexdump of my preferential BIOS settings, not the factory default settings. So either this is not where the settings are being read in, there's a checksum I'm failing, or some other reason the BIOS settings I "force" are not read, and factory defaults are loaded as a result.
od -Ax -tx1z -v /dev/nvram
Any help or guidance is greatly appreciated, let me know any output or screengrabs that would be helpful.