Hello, On May 30, 2023 12:42:39 PM EDT, Linux User #330250 <linuxuser330...@gmx.net> wrote: > On 05/30 2023 17:13 Stan Johnson wrote: > > On 5/30/23 7:16 AM, Ben Westover wrote: > >> The GRUB Manual [1] says that the PPC port of GRUB only supports booting > >> Linux at the moment. AFAIK booting macOS with GRUB on x86 machines works > >> by just chainloading macOS' UEFI bootloader. I assume this is what yaboot > >> does as well, telling Open Firmware to load OS X's blessed binary instead > >> of the second stage of yaboot and Linux from there. All we need to do is > >> find a way to support Open Firmware chainloading from within GRUB. > > AFAIR yaboot does its magic within the CHRP boot script. It would be > relatively easy to add an option to load GRUB, I guess. The "chain" > would then start by choosing Mac OS (Classic), Mac OS X, or GRUB, via > the yaboot CHRP script. But then, GRUB would be only managing Linux.
That makes a lot more sense now. The "first stage" of yaboot where you select Linux, OS X, or CD Boot is actually a script run by Open Firmware, and that's how it can so easily chainload, since it's just a script selecting which binary for Open Firmware to load. In that case, instead of trying to integrate chainloading functionality into GRUB itself, we could just set a similar script to run before GRUB that allows you to make that selection. -- Ben Westover
