[Clfs-support] Cannot login on serial port (embedded ARM, busybox)

[Andrew Bradford]

On Fri, Oct 14, 2011 at 6:40 PM, Lance Jump <lancej29 at gmail.com> wrote:
> The board I have is the OpenRD client. It is based on the Marvell Kirkwood,
> which is the same processor used in the PlugComputer.  I have a config file
> for an older kernel (2.6.18).

Can you try a CLFS build using 2.6.18 kernel source?  The procedure
should be the same, just you'll end up with different headers and an
older kernel than what the book says.

> The reason I wanted a working config from the CLFS build is so that I can
> check non-hardware related things like devpts and tmpfs settings.  I
> compared the one you sent to mine and found numerous non-hardware related
> differences.

My kernel config is not at all optimized to have "the right stuff" in
it.  It's just the first config I had that worked well enough to boot.
 I wouldn't consider it to be a great example, but it is a working
example.

> I think since the ${CLFS}-final has already been created at that point and
> there are other things being fixed up for it, that doing it in -final makes
> the most sense.
>
> I will try to get either the trac ticket or patch this weekend.  Does the
> protocol require a trac ticket against which to submit the patch?

If you just send a small-ish patch to -dev list, there's no need to
open a trac ticket.  My stance (not necessarily anyone else's) is to
open tickets when the change will take a long time, involve more than
just me, or if I don't have the urge to fix it right now.  If you're
fixing something you just found and it's small, just send a patch.

> I have done some more experimenting and found some interesting things.
> First, with only console and null in /dev I get repeated "Can't open
> /dev/tty1: No such file or directory" (tty1..6) messages.  When I create
> these nodes, the messages go away.

You shouldn't need to create these nodes.  mdev should be doing that
for you.  Of course, mdev doesn't run till after mounting everything
in the startup script, so we're back to one of your original problems
:)

> I can replace the sysinit line in inittab with just about anything else (for
> example "mount -a" or "/bin/busybox --help" and it appears to do exactly
> what is expected. In fact, I used the "mount -a" to locate missing mount
> points in /dev (/dev/pts and /dev/shm).
>
> I can also use various commands other than getty for the other lines in
> inittab and they do as expected. For example if I used "touch /tmp/test" it
> creates or updates the file /tmp/test. I seem to be able to do most things,
> but I just can seem to execute a script no matter how simple.  For example,
> if I put the touch command in a script file and try to execute it, it does
> nothing.

I think your ash might not be built right if you can't run scripts.
That's odd, especially if things like touch or mount work.  Are you
changing the BusyBox config at all?

> Another interesting things is that device detection for things like USB mice
> and thumb drives and SD cards all appears to work except that none of it is
> ever mounted.  The drives are identified from driver messages as sda, sda1,
> sdb... but nothing ever appears in the /dev directory.  By the way, this is
> also an indication that the kernel believes the serial port to be the
> console.

mdev should be taking this info from the kernel and populating /dev for you.

-Andrew