There are no BIOS parameters associated with this capability - and certainly none that could do anything once the O/S has started booting (the BIOS is no longer running from then on). Usually, this capability is handled by the O/S). Check you O/S' Configuration/Setup subsystem for related parameters...
This message was posted on behalf of Intel Corporation
Thank you very much to N. Scott Pearson for the information posted previously.
I just wanted to confirm the above information as correct, there is no option on the BIOS to turn off the HDD.
This option might be available on the OS, since you are using Linux I just wanted to let you know that Intel does not test and validate Intel® NUC on Linux; however we know that a lot of NUC owners are using it successfully on many different Linux distros.
So, at this point the best thing to do will be to access your Linux distro's website and forums for peer assistance with this matter at:
Any questions, please let me know