Some BIOS questions
 

I need to replace my BIOS battery. Apparently, this can require a reinstall of the BIOS. How do I backup this up in Linux and then re-apply it after the battery replacement? Thanks.

Hardware? System type?

Strictly speaking, I don't think you can take a copy of your BIOS from the BIOS chip, though of course I may be wrong.

Perhaps http://www.chephrenrepairs.com/bios_battery.html may set your mind at rest with regards backing it up.

leave computer turned on
 

leave computer turned on while you replace the battery is what I do and it works for me.

Don't think I want to leave the computer plugged in and turned on while I open it up and replace the CMOS battery.

If you still have a printer with parallel interface and a parallel port on your computer, you can use print screen to have at least a paper backup.

Those were the days ;)

Afterwards you can verify the settings against the paper backup.

Personally I do not worry about it: if I'm not mistaken a lot of the settings are nowadays detected by the BIOS and if I can't get it right, I can always take it to the shop.

I don't think you ever need to re-flash a BIOS after removing the CMOS battery, the most that will happen is the BIOS settings may be erased, in which case you would need to set them again.

jacatone,

You will not lose the BIOS by changing the battery. The BIOS is the fixed program the computer runs when you switch it in. The BIOS saves some user changeable data in CMOS RAM memory, which is powered by the PSU during normal operation and by a battery when the power is removed.

In my experience, you have several minutes to change the battery without losing the CMOS data.
Make a note of all the settings in the BIOS screen. Change the battery and check the settings.
If you can keep the time down, I would be surprised if any settings have changed, unless you manage to short the two battery connectors in the process.

Indeed, its often a problem to get rid of incorrect CMOS settings that prevent a PC from booting, even removing the battery and shorting the battery contacts together.

Replacing the little dime shaped battery did the trick. Even seems to run better afterwards. Weird.