> Date: Mon, 18 Sep 2023 19:21:09 +0200 > From: Martin Husemann <mar...@duskware.de> > > On Mon, Sep 18, 2023 at 06:14:58PM +0100, David Brownlee wrote: > > Specifically in the absence of any other information (empty devname? > > etc), would it not be reasonable to fall back to the bootme marked > > filesystem as a root filesystem candidate? I'm thinking about > > minimally configured disks moving between machines > > No, the bootme is usually on the EFI system partion, which is also > usually not set up as a root partition for NetBSD :-)
Why would bootme be usually set on the EFI system partition? The documentation in gpt(8) needs to be clarified -- and I'm not sure there's any other canonical reference about it in any of our documentation -- but it sounds to me like it is supposed to be: (a) where NetBSD's efiboot finds the kernel, and/or (b) what root partition the kernel will use. It's not clear what else the bootme flag would be for, and it seems that unless boot.cfg instructs the bootloader to pass a different root device to the kernel with the `root' command, the same partition that was used to find the kernel is a reasonable default choice of root device. The bootme flag certainly not used to tell the machine firmware where to find efiboot -- it's is vendor-specific, a BSDism. It's not obviously where efiboot finds boot.cfg, since that's in esp:/EFI/NetBSD/boot.cfg or, if not there, whatever parsebootconf resolves unqualified `boot.cfg' into -- which may be the bootme-flagged partition but it's not clear to me in a cursory search that it has even looked for a bootme-flagged partition at the point it needs to resolve boot.cfg. Whatever the purpose is, we need to have it documented clearly; right now I can't share kre's certainty about what it is _not_ to be used for.
