Talked with Debian nbdroot author and he agreed we shouldn't support their obsolete syntax in dracut.
Their root=/dev/nbd[0-9] is no longer needed. Also their syntax was very standardized requiring
a separate boot= parameter.
This introduces detailed cmdline parsing, warning or aborting if the
cmdline does not contain arguments according to the spec.
Makeing sure the parsers don't just call getarg for netroot et al,
allows their reuse inside netroot to analyse dhcp root-path as well.
Hence we can get rid of the current netroot hooks. The hook itself stays
in order to add further modules which should run before netroot handlers
are called.
This has one drawback: nfsroot needs some more logic to handle nfs
specific data inside dhcp root-path.
The parsers have been writting according to current discussions about
cmdline arguments. This lead to the "discovery" that some test-cases
violate the spec. These tests have not been removed, but change to
"must fail".
This adds support for a command line option netroot=, which is currently
equivalent to root=. This will allow us to break out handling in NBD and
iSCSI to support constructs such as "root=LABEL=/ netroot=dhcp" to make
use of our block device handling with network attached devices.
iSCSI has not been changed in this patch as I don't currently have a way
to test it.
Harald Hoyer