On 16/06/2024 23:39, Nuno Silva wrote:
And of course, all the rules get bent by the various manufacturers. Bear in mind that basic EFI predates vFAT so even in UEFI vFAT isn't actually mandatory. Apple don't use it, iirc. There's nothing stopping GNU's OpenBIOS project or whatever it is using ext4. But vFAT is the official "lowest common denominator" which everything must support if it's not "single vendor for hardware and software". Which is why, of course, MS can't play fun and games - if they say Windows won't support vFAT they'll get hammered for anti-trust.
But there are systems using exFAT, right? You mean UEFI firmwares will happily accept other filesystems?
I don't know. But the formal specification of UEFI says it must accept vFAT (I believe exFAT was not acceptable because Microsoft had patented it). It does not say it can't accept other stuff. Which is why Apple doesn't use vFAT.
And it explicitly states the version of vFAT. I don't know which version, but it's along the lines of "version X dated Y", so that is locked in stone.
So basically, the UEFI spec says it CAN accept multiple filesystems, but it MUST accept vFAT if it wants the moniker "Universal". So unless (and probably even if) it's Apple hardware, it does support vFAT.
Cheers, Wol
