Hi,
> On 5/19/15, Arno Schuring <aelschur...@hotmail.com> wrote:
> >
> > Note that you can add break=premount to the kernel cmdline
> > to force an initramfs shell, then use sh -x /scripts/$phase/$script
> > to manually step through the initramfs procedure.
> >
> > You can use "grep maybe_break /usr/share/initramfs-tools/init" to
> > check the valid break= values, and their order.
>
> stepping sounds like a great way to debug, but i'm out of my depth. i
> don't know what premount is (is that a phase? a script? something
> else?), or what initrd does (all i know is it's a ramdisk and has a
> fake root fs for some reason). i will of course be happy to try this,
> but i won't know what scripts to run, in what order, or what the
> results will mean.
>
premount is just one of the breakpoints in the initramfs where you can
break out and get a shell. The init procedure is completely shell-based,
you may try reading /init lines 208-238 to get a feel for it. Basically,
every phase is represented as a directory in /scripts, and the order in
which the scripts are run is determined by a /scripts/$phase/ORDER file
in each directory.
/scripts/local-top/cryptroot is probably the most interesting script for
you to run, and I don't think it has many dependencies since you're
not using lvm. But ORDER is itself a shell script as well :)
Beyond that, I don't think I can be of much help. I only know about this
because I'm using a custom unlock procedure for my rootfs. I can't tell
you about the design of the initramfs, nor do I know if what I'm
advising here is the easiest way.
>
> > Also, can you verify that /conf/conf.d/cryptroot exists
> > in the initramfs and contains the correct line?
>
> instead of rebooting to determine this and trying to transcribe it, is
> it ok to extract the initrd as it is on disk? i did so and got this:
> "target=toshiba-root,source=UUID="...",key=none,rootdev" (where "..."
> is the correct uuid according to blkid for /dev/sda3, which is the
> partition on which encrypted root resides).
>
> does that seem correct?
yes, that should be correct.
>
> >> in fact, in the initrd busybox shell, i can do cryptsetup
> >> luksOpen /dev/sda3 toshiba-root. i do not know how or where
> >> to mount it, however. mounting it on / not work.
> >
> > You need to mount it (readonly) on /root. Then exit the initramfs shell
> > and the boot should continue normally.
>
> on /root, as in the superuser's home dir for dot files etc.?
Yes. There is no home dir in the initramfs. It's a bit counterintuitive, but
it does make sense to mount the real root filesystem on /root. It's just a
shame that 'root' has more than one meaning.
Regards,
Arno
