Doctrow's Law: "any time someone puts a lock on something that belongs to you, and won't give you the key, that lock isn't for your benefit." Cory Doctrow
I mentioned in a previous article that I booted FreeBSD into a an Asus Trinity laptop, but gave no details on how to do this. The obstacle is the UEFI BIOS that Microsoft recently "imposed" as a standard.
UEFI bios is more complicated than regular BIOS and when it was adopted industry-wide, there were outcries from all kinds of influential people because it was regarded as a proprietry obstacle to open-source computing - a kind of bid to shut out Linux, FreeBSD and other open-source software from running on modern computers.
I guess if sticking your own pre-boot software on people's computers isn't bad enough, locking out the competition from all platforms in the name of security is about as obtuse a Trumpian commercial-political manuver as it gets. I don't think I've seen anything quite like that since the Hunt Bros. tried to corner the silver market in 1979. And failed.
Secure Boot is hyped as software to protect against boot sector viruses, but boot sector viruses are hardly a big problem nowadays in IT. Back in the days of floppy disks (1980s) and public computer labs they were a big problem. Kids would come in with infected floppies, do some work, infect the computer, then someone else would come in afterwards and get their floppy infected. Since then, virus-scanning software, firewalls, and technical awareness has all but eliminated boot-sector viruses.
So why so much fuss to create Secure Boot? Well, it coincidentally serves a dual-purpose of being a rather convenient commercial strangulation point to prevent people from compiling and installing their OS of choice on their own computer. A kind of super-DRM for asipring monopolies who would like to treat all other operating systems as "boot-sector viruses".
The fact that Microsoft leveraged its influence to impose this standard made a lot of people angry. Since then, due to public pressure, the standard has been reworked to allow people to turn off secure boot in BIOS, but Microsoft-compliant hardware manufacturers apparently still can't opt-out of "UEFI compliance".
In any case, on the Asus Laptop, it is possible but not obvious on how to disable Secure Boot, but the details are in fact out there, as Andrea Venturoli pointed-out:
I've dealt with several crappy Asus notebooks and they all allow disabling SecureBoot, altough the options are a bit hidden.
Try: disabling FastBoot on the Boot page; on the same Boot page, enable "Launch CSM"; on the security page disable "Secure Boot Control"; save and reboot; reenter the BIOS settings; you should now be able to allow legacy boot devices.
I can attest that these steps Andrea mentioned work on the Asus K55-N, so if you have one of these laptops or similar UEFI BIOS (American Megatrends) you should be able to boot into FreeBSD using the latest uefi CD boot image.