Matt Fleming <[email protected]> wrote: > > Does anything ever enter the kernel through startup_64 in head_64.S?[*] Do > > all 64-bit mode entries always enter through one of the EFI entry points? > > Which head_64.S? There are two ;-) > > Assuming you mean startup_64 in boot/compressed/head_64.S, then the > answer is "yes". 64-bit BIOS boot loaders will jump there.
Sorry, yes, that one. > I'm fairly sure it's possible to boot that way on EFI too, you just > lose some of the newer functionality that is dependent on the EFI boot > stub. But I don't remember the last time I tried it. > > In general, we've always tried to maintain backwards compat, but you > don't get the new features without switching to the EFI entry points. > > Whether or not any distros are still using the old 0x200 entry point > for EFI is a good question, though. I think I have to assume that there might be. David
