On Fri, Dec 22, 2023 at 11:36:24AM +0200, Toomas Soome wrote: > > > > On 22. Dec 2023, at 11:09, Mark Millard <mark...@yahoo.com> wrote: > > > > Tomoaki AOKI <junchoon_at_dec.sakura.ne.jp> wrote on > > Date: Thu, 21 Dec 2023 23:21:00 UTC : > > > >> On Thu, 21 Dec 2023 14:22:14 +0100 > >> Dimitry Andric <d...@freebsd.org> wrote: > >> > >>> Yeah, my procedure is the same as yours: I first copy > >>> /boot/efi/efi/freebsd/loader.efi to /boot/efi/efi/freebsd/loader.old, > >>> then copy the freshly built and installed /boot/loader.efi to > >>> /boot/efi/efi/freebsd/loader.efi. I don't see a technical reason why this > >>> could not be just another step in the installworld procedure. > >>> > >>> That said, I am unsure if the pathname /boot/efi/efi is always the same, > >>> at least for all UEFI systems. It is the default layout when you do a > >>> regular install with recent installer onto a UEFI system, but some users > >>> may use completely different mount points. So you should still have some > >>> way of configuring the default location for loader installation. > >>> > >>> Also, on default installations a fallback entry named > >>> /boot/efi/efi/boot/bootx64.efi is made, essentially another copy of > >>> loader.efi but with a different name. Namely, the default name that UEFI > >>> (on x86_64 at least) searches for, if it doesn't know anything else. I.e. > >>> if it isn't configured via efibootmgr(8), or the EFI variables have been > >>> junked for some reason. It might make sense to also update that file. > >>> > >>> -Dimitry > >> > >> Just an idea. > >> > >> It would be nice if loader.efi (hopefully, boot1.efi,too) could pass > >> "where am I placed?" info, maybe via kenv. > >> > >> Would need boot1.efi to pass something (ideally, "where am I booted > >> from?", but "boot1_used=1" is sufficient). > >> > >> To do so, loader.efi can confirm whether it was loaded via boot1.efi or > >> directly from UEFI firmware. If nothing is passed to it, it can probe > >> "where it is?" using UEFI call and set it, otherwise, it should > >> be /boot/loader.efi, so nothing is needed to do. > > > > To my knowledge aarch64 and armv7 never use the copy in > > /boot/loader.efi during a boot. It has to have been copied > > into the appropriate msdosfs such that it has an > > appropriate path and name there. That is what is found > > and used during the boot. > > > All UEFI systems start from ESP (EFI System Partition). The only good reason > to install boot1.efi there is when you have very small ESP and need to save > that space - and in that case the boot1.esp will search and execute > /boot/loader.efi. > No, this is not the only good reason, or even the least important reason.
boot1.efi is extremely convenient for the normal (*) configuration where machine is dedicated for a single FreeBSD system. It finds and chain-load real loader.efi from the first UFS GPT partition which I always assign to the root. This means that I do not need to care about updating loader.efi at all, it is done during normal installworld. * at least for me I use this setup for >5 years on all my disk-booting machines. > The problem about boot1.efi (or any other UEFI chainload) is that loading > file and executing it will not replace current program in memory, but will > add new one, this may be problem with systems with minimal memory > configurations. And yes, boot1.efi is not really platform specific - it is > just another EFI application - one can build and use it on arm (or any other) > systems and then it will load and start /boot/loader.efi. > > starting loader directly from ESP has few advantages — you wont waste memory > for boot1.efi, you save a bit of boot time, you can use auxiliary files from > ESP to pass some information to loader.efi (for example to tell where your > rootfs is in case of multiboot setups). > > the boot1.efi could be a bit more appealing if it would be able to load and > start kernel directly, allowing to build very memory limited setups, but then > again, it does sound like very specific corner case. > > rgds, > toomas > > > > > >> If no related kenv is set and freebsd-boot partition exists, it should > >> be booted with legacy (BIOS) boot. > > > > If there even is a "legacy (BIOS) boot" is a platform > > specific issue as far as I know. > > > >> The easiest to be set by loader.efi and/or boot1.efi would be raw UEFI > >> device path. So would need analyzing where actually is on booted > >> FreeBBSD environment. > > > > See the earlier point about aarch64 and armv7 not using > > /boot/* files while loading the FreeBSD loader: the > > FreeBSD loader variant used is the first stage able to > > look inside UFS or ZFS file systems. Loading and > > starting the FreeBSD loader happens before that stage > > in those types of contexts. > > > >> . . . > > > > Also, to my knowledge, powerpc (32-bit), powerpc64, and > > powerpc64le do not involve any variant of loader.efi or > > UEFI/ACPI or UEFI/DeviceTriee in their boot sequnces. > > Again: more platform specific rather than generic. > > > > === > > Mark Millard > > marklmi at yahoo.com > > > > > >
