[nas-2000] Re: custom kernel/ initrd problem

  • From: Felix Mellmann <mellmispam@xxxxxx>
  • To: nas-2000@xxxxxxxxxxxxx
  • Date: Fri, 04 Jan 2008 22:10:08 +0100

Hmm, okay I guessed your answer already :)
Nevertheless, did you complete my debian how-to and have this image running?
When you did this, you installed the initrd-image shipped with the disk image.

A fresh NAS box has got a bootloader, linux kernel, initrd-image, application image and some misc files. The bootloader loads the kernel and the initrd-image and starts the kernel. The kernel itself unpacks the initrd and starts /sbin/init from that image (for making that issue complete - normally the kernel will run /linuxrc but due to root=/dev/ram on the kernel command line, the kernel will run /sbin/init ; the kernel command line is not changeable, because its included in the bootloader). /sbin/init treats itself differently wether it has the process ID (PID) 1 or an other PID greater than 1. So I summed up - I didn't want to change the bootloader and the kernel. So the kernel will always load /sbin/init from flash and give the PID 1 to that process. If I would write a program, that calls /sbin/init from hdd to start the boot process of debian, that process will get an higher PID and doesn't boot debian. Philipp helped me out, there is a system command, which exchanges the flash with the hdd and the boot process starts. And so does my little initrd. This one is essential for booting from hdd and shouldn't be replaced.

About the kernel - I think there are some people in the forum, who know much more about the kernel and the hardware specialities on the NAS than me ^^

As far as I know, there is a kernel from an other NAS available with usb-support available and it should work very well. But I wonder if there is a way to get dmraid compiled...

BTW.: I have written a little program which reacts on pressing the power button and shuts down the NAS. I should post it in the wiki ..

My NAS does its job very well, I have Samba, NFS server and a subversion server running. IMAP mailserver is planned, as soon as I get the NAS to power on on telephone ring ^^

greetings, Felix

Dan Luedtke schrieb:
Hi Felix,

Am 04.01.2008 um 16:10 schrieb Felix Mellmann:
.. but you can use a larger initrd if you want, but you have to remove the "Application" file in flash. I kept that one because its then easier to switch to the old system.

OK, thanks for that, i will try it.

If you have a look on my initrd, there are just some needed devices, 2 essential libraries and the modified /sbin/init which swaps from flash to hdd.

How to swap over to hdd? I thought the kernel doesnt care where the initrd comes from as long as it is startet in some way. The bootloader starts the initrd, doesnt he?! I will see, as long as the redbootloader is working i will have all oportunities :)

I don't know what you want to do with cryptonas

it's less an important thing, its more a how-far-can-i-go-with-this-little-gadget thing for wasting my free time :) Maybe some day i'll plug my usb thmubdrive holding the keyfile into the unused USB port, then the NAS starts decrypting the volume and grants me access to it via network (samba for example would be nice) as long as the thumbdrive is in the port.

An easy way of open and close encrypted volumes with personal data for reading/backup. But thats just a possiblity, today it's still this testiing/learning thing.

Btw. can you please tell me which kernel sources you have used? The vanilla (unpatched) kernel sources don't include the drivers for the board used in the NAS... so I haven't build a kernel for the NAS by myself.

Uhm, ok. Thats not good to hear.
I have the vanilla from kernel.org
Shoul i use the debian kernel source? Another long night of compiling for the NAS :) I really should think about cross compiling.

Where do you have the kernel from? Are there prebuild kernels somewhere on the net? I need the device mapper, loopback device, usb support etc :( Thats the problem.

2nd Btw. where did your 3 MB initrd image came from?
shame on me, i just used
% make menuconfig
% make-kpkg --initrd kernel-image

Then there was an initrd.img-2.6.xxx-xx-blah in /boot.

Using debian on the NAS is a great deal! Thanks for that btw. I saw the drive at "Media Markt" (an annoying German end-consumer electronic market, for those how don't know) with the sticker saying "New Firmware. Supports Bonjour, HDD Encryption, Twonky Media...". HDD-Encryption made me thinking "Uhhm, lets see what they call encryption." Spending my last money to the NAS i now have a little toy for big games (see above) including world domination :)



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