Studying GRUB's other user-space subsystems...
For i386 EFI machines there's a `grub-dumpdevtree` shellscript lightly wrapping the `ioreg` command with some hardcoded arguments & reformatted output.
For IEEE1275 machines there's a `grub-ofpath` command which performs some generic initialization, handles common commandline flags, defers to `grub_util_devname_to_ofpath` outputting results if any, & cleans up.
And there's a shellscript registering numerous autocompletion callbacks.
1/2!
There's a handful of shared utils between all those callbacks, with the callbacks branching over special envvars to determine how to compute their results. Usually by invoking those shared helpers.
I don't think its worth saying more.
1.5/1.5 Fin for today! Next I'll be skimming the rest of the code, remarking where I find something notable. Then I'll study Linux's bootup!