Re: Specifying root device in /etc/fstab

[mlelstv%serpens.de@localhost (Michael van Elst)]

kre%munnari.OZ.AU@localhost (Robert Elz) writes:

>I don't see the lack of the ability to specify the partition in the same was
>as nearly as big an issue - the device knows which of its partitions is
>the root,

The device doesn't know anything about it. You may chose a convention
like using the first partition as root or have a platform that sets it
as a literal boot parameter in some config file. Most of our platforms
allow such flexibility.

In every case the kernel finally selects a root partition to be mounted and
exactly that partition should be referenced in fstab, what is written there
will be remounted read-write during the boot process.

Now of course you can duplicate the information what partition you
selected for booting or just assume that nobody would ever use anything
other than partition 'a'. And obviously you rule out that someone is
using a wedge here, because there is no such thing as a partition of
a partition. Thus my suggestion is to not bother with that duplicate
partition information, but have something that is just an alias for
'whatever the kernel uses as read-only root'.


>I have no idea what resizing wedged has to do with any of this.

It currently stops you from using wedges on the one-size-fits-all images
for arm SoCs as the first thing done is resizing the OS partition while
it is still mounted read-only.
But resizing a wedge is not yet implemented, you can only re-create it
and only if it is not in use. The existing resize hack would require an
extra reboot cycle to be usuable on a wedge.

The problem Jared tries to solve is that without wedges the same image
will be visible as different devices, depending on what hardware
configuration exists and wether some pluggable devices like SD cards
are found or not. Unlike with regular installations (sysinst...) the
user has no means to configure this and apparently should not have to
do it.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."