On Tue, Dec 26, 2017 at 12:15:16AM -0500, Alan Corey wrote: > Seems like a simple solution would be to expand it to the size of the > partition, or if there's no partition maybe ask. So you use your > fdisk or gparted or whatever first if you know you want other things > in part of the space. Then have the expansion respect the partition > size. OpenBSD setup asks early on if you want to use the whole medium > space. Same idea, this is when creating a disklabel I think. It also > simplifies replacing the contents of a partition with part of another > operation system for instance.
rpi.img isn't an installer though, and we probably should not assume that the user has an interactive setup and can provide input. you can shrink a filesystem, though resize_ffs doesn't allow it on FFSv2 for some unclear reason.