>>       Anyway I think there's a simple method to live without the
>> initramfs. Everything which is done from initramfs could be done the
>> same way from a disk partition, which might make it easier to debug:
>> have a /os directory containing all the necessary subdirs, /os/proc,
>> /os/sys, /os/dev, /os/run /os/usr, /os/lib, /os/var, /os/home... , mount
>> the first five, create the few necessary files and symlinks and
>> switch_root() to /os. This is exactly what your initramfs does.
> Nope, that negates one of the principle reasons to use an initramfs in
> the first place.  You assume the stock kernel can see the drive where
> you intend to put this new partition; one of the big drivers of initrd
> in the first place was exotic hardware, etc. so GRUB uses BIOS
> (including extension ROMs on controller cards) to load both the kernel
> and the initrd so it can take whatever steps are needed, i.e load the
> right modules, start lvm, setup encrypted filesystem magic, etc. to make
> the main drive/partitions/etc. visible.  Your idea could deal with most
> everything that didn't need a kernel module but totally fails at that
> task.