Though I think we really do need an OS-agnostic solution long-term, the short(er)-term option I like the best is to introduce the grub2/update_nvram preseed so that curtin can configure grub to not install a boot entry in a more persistent way that survives grub package upgrades. I discussed this w/ Ryan at a sprint last month, and he seemed ok with it from the curtin side. Assuming that is still the case, I'll prepare a PR for the Grub side and see if I can get that preseed option landed.
Though I think we really do need an OS-agnostic solution long-term, the short(er)-term option I like the best is to introduce the grub2/update_nvram preseed so that curtin can configure grub to not install a boot entry in a more persistent way that survives grub package upgrades. I discussed this w/ Ryan at a sprint last month, and he seemed ok with it from the curtin side. Assuming that is still the case, I'll prepare a PR for the Grub side and see if I can get that preseed option landed.