[Buildroot] Help - Buildroot-2010.11 Don't know what changed

[Ken McGuire <kenm@desertweyr.com>]

Hi Chris,

On Thu, 2010-12-02 at 12:24 -0500, Chris Kerios wrote:
> On Thu, Dec 2, 2010 at 12:08 PM, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
> > On Thu, 2 Dec 2010 11:27:09 -0500
> > Chris Kerios <ckerios@gmail.com> wrote:
> >
> >> I am working with the 2010.11 release on a PC-104 Geode LX w/Compact
> >> Flash card. Fedora 14.
> >>
> >> I built a minimal system with all the defaults, no external toolchain:
> >>
> >> Kernel = 2.6.36.1
> >> uClibc = .9.31.x with .9.31.x.config file
> >> Busybox = 1.17.x with 1.17.x.config file
> >> gcc = 4.3.x
> >> bootloader selected = grub
> >>
> >> I have not added any files/applications to be built, so all that is
> >> being built is the toolchain, kernel, grub and busybox.  Everything
> >> downloads and builds fine!
> >>
> >> The problem is when I copy to flash and boot the system it comes up as
> >> read-only!  I copy things to the flash as root and preserve all
> >> permissions, etc.  I've looked at the mailing list and long ago the
> >> threads said to have the entry in inittab remount the filesystem as RW
> >> and it should correct the problem.  The issue is my default inittab
> >> file has this entry in it so I don't understand why I am seeing this.
> >>
> >> If I execute the command manually from the command line after logging
> >> in, it mounts the filesystem back as RW just fine.  Also, if I include
> >> a "rw" on my kernel line in grub.conf the filesystem comes in as RW.
> >>
> >> Is this a busybox issue?  I am using all buildroot defaults.  Any
> >> thoughts or ideas of things I can check?
> >

I just ran into the same issue but I'm building for an ARM Cortex-A9.
I've used buildroot for many years as well as busybox, and I seem to
remember a similar issue a few years ago.

I solved it in my case by moving the remount line till after proc was
mounted. I also removed the mount -a, but for other reasons. I haven't
put it back yet to see if it works or not.

#null::sysinit:/bin/mount -o remount,rw /
null::sysinit:/bin/mount -t proc proc /proc
null::sysinit:/bin/mkdir -p /dev/pts
null::sysinit:/bin/mount -o remount,rw /
# null::sysinit:/bin/mount -a

I also seem to remember that there was a fix (maybe in busybox, but I'm
not sure) applied and the standard inittab worked till now.

See if that works for you.

   ...ken...


> > We have :
> >
> >  null::sysinit:/bin/mount -o remount,rw /
> >
> > in our default inittab in fs/skeleton/etc/inittab. This should
> > automatically remount the root filesystem as read/write when the system
> > boots. Maybe you are using a different filesystem skeleton ?
> >
> > If not, then edit this line to be :
> >
> >  ::sysinit:/bin/mount -o remount,rw /
> >
> > and see if you have error messages.
> >
> > Thomas
> > --
> > Thomas Petazzoni, Free Electrons
> > Kernel, drivers, real-time and embedded Linux
> > development, consulting, training and support.
> > http://free-electrons.com
> > _______________________________________________
> > buildroot mailing list
> > buildroot at busybox.net
> > http://lists.busybox.net/mailman/listinfo/buildroot
> >
> Hi Thomas,
> I just checked everything you suggested.  I am and have been using the
> default buildroot filesystem skeleton.  The inittab file entry is
> exactly as you say it should be.  I also just edited the file and
> rebooted the system with no luck.  There are no additional messages to
> report to you.  I can issue the remount command and get it to come
> back as RW it just doesn't want to boot to RW.  Darn!
> 
> Lionel was saying earlier it might be kernel config but I don't know
> where in the kernel I see anything that has to with an option of
> bringing up the root filesystem as read-only.
> 
> Like I was saying earlier, I did a full build on 2010.08 with apps and
> didn't run into this.  I didn't build 08 as a minimal build like
> described above.  I am going to rebuild that release with the minimal
> default set and see if I get this same behavior.
> 
> Chris
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot
>