DSM-G600, DNS-3xx and NSA-220 Hack Forum

radiusweb wrote:

Whatever you do, DO NOT chmod the root of any partition to anything other than 777.  If you change the root of the partition to anything other than 777,  (drwxrwxrwx) the hotplug scripts on your DNS-323 will notice this change and react by executing this command:

chmod -R a+w /mnt/<your partition>
(Not exactly good news for your Linux distro.)

Using the subdirectory idea, I think it's possible to work around this for non-chroot, i.e. booted Linux installations, too. With initramfs it's possible to boot with a subdirectory (e.g. linux/) as root. I've tried the following in an /init script of an initramfs, and it works nicely in qemu (I assume it'll also work on the real device):

/bin/mkdir -p /mnt
/bin/mount -t ext2 /dev/sda /mnt

cd /mnt/linux
exec /usr/sbin/chroot . /sbin/init

And having your custom firmware in a single separate directory (instead of filling your first volume with lots of directories) doesn't seem too bad.

radiusweb wrote:

Yep.  Sounds good.  I'm looking forward to a true firmware replacement.  Then at no point during system startup will any process try chmodding anything you don't want chmodded.  Control will finally be in the hands of the user.  The module based kernel replacement is a great start though.  At least you can run your own kernel as you see fit.

I've uploaded a new Linux image yesterday. It's installed into "linux/' on the first volume and boots the 2.6.12.6 kernel. Included are new kernel loader modules for firmwares 1.02 and 1.03 that should be much more reliable than the first version. In addition to the led and poweroff programs, I've also added two more DNS323-specific small utilities for temperature, and fan control. Have a look at www.inreto.de/dns323/ - the binary image is in bob-clfs/, sources are in source/. Installing the image is only slightly more complicated than the fun-plug, and a script is included that creates an initial configuration automatically from firmware files.

radiusweb wrote:

Do you have any information on compiling your own kernel from sources on the 323?

Kernel compilation is straight forward, but:
- Vanilla kernels won't work because they lack support for this specific platform. Use 2.6.12.6 sources from ftp.dlink.com. D-Link's kernel sources contain a .config file that you can start with
- Use gcc version 3, gcc4 doesn't work.
- Cross-compilation is much much much much much faster.
- Of course, you need a root filesystem to boot.
- And unless you install to the root of a drive (and get the problems you found), you will need an initrd or initramfs.