On 2024-06-16, Wol wrote: > On 15/06/2024 20:35, Dale wrote: >> I'm not opposed to efi. I remember when the old Grub reached its >> end of life. Grub2 is different but it works. I don't use the eye >> candy part so that makes it even easier. The biggest thing, I copy >> my kernels and such over manually and I keep a couple older ones >> that I want to be available. I also plan to install memtest, a >> rescue image or two and those need to be available as well. I may >> still use Grub, I may not. Right now, I'm clueless. I'm just >> trying to follow the docs which given all the options available are >> confusing to follow. > > At the end of the day, all these things are pretty much the same. Back > in the ancient days, you had a switch panel you toggled to put in the > boot code. > > Then they put a basic interpreter in ROM. > > Then they got rid of basic and put code in that said "here's a bit of > disk controller code, go to chs(0,0,0), read one block and execute > it". > > Now UEFI is just a bit more fancy code that says "here's a gpt table > reader, a vFAT driver, and a mini program that looks in any FAT > partition it can find for an EFI directory, and runs whatever it finds > in there".
I thought UEFI firmware as a replacement to PC BIOS tried to do more, including handling video modes before loading the boot code. > So the principle hasn't changed, but the detail has. > > 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 was under the impression (not having any UEFI computer here, so not from personal experience, just from seeing instructions given to other people a few times) that this was pretty much the usual "every system wants the Microsoft FS", but made worse because instead of the commonplace and widely-supported FAT* it had to be exFAT. (One might wonder why does it have to be a Microsoft filesystem at all...) Or is the problem that many UEFI bootloaders that are in the firmware behave in a less than optimal way with implementation details and unimplemented features? > More and more everything is turning into "System on a chip", and that > includes the bios! It has just enough of a driver now to read > everything it needs from the attached storage, and that's your modern > UEFI. -- Nuno Silva
