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How to create a new root file system?

lakshmipathi
lakshmipathi Posts: 12
in Kernel Development

How to create a new root file system a kernel?

I'm searching for answers for past few weeks . :S

Is LFS only way out? Or should i try something like virual appliances ? something like rpath or jeos etc....I need to create a new root file system , from scratch so my kernel can use it.

Any help ?:blink:

Comments

  • favoretti
    favoretti Posts: 5
    Hi there,

    Could you please elaborate a bit on what you're trying to achieve? "Create a new root file system a kernel" ?

    Cheers,
    Vlad
  • lakshmipathi
    lakshmipathi Posts: 12
    Thanks,Vlad.
    I have downloaded and complied a kernel (2.6.25.4) . Now I want to Know how to create an new root file system ( i'm learning about Linux). I have a new partition (say /dev/sda6) with 10 GB , I have formatted it as ext3. How to proceed here after?

    I want to learn about these stuff , which i believe ,will be really useful while i'm trying to create my own distro or virtual appliance kind of stuff,in future.
  • atreyu
    atreyu Posts: 216
    So you want to roll your own OS? Well, then look at www.busybox.net for starters. You can get all the necessary binary utils required for a minimal OS from that one great app. The only missing thing is an initscript, which you write yourself.

    Basically, you create an initrd (initial ramdisk) image, which you tell your kernel to load. Think of it as a mini-OS that will run in memory. Making the initrd is pretty simple. you just create the directory structure and populate it with the busybox apps. There is a great tutorial here:

    http://www.linuxfordevices.com/articles/AT4375744671.html

    Once you get that mastered, you can move on to transferring this image to internal storage.

    good luck!
  • favoretti
    favoretti Posts: 5
    Hi,

    Well, then indeed you could follow LFS manual for installation of vital software that you'd need besides of the kernel.

    Create root partition, create swap. Mount the root partition somewhere where you will be able to install other software, say /mnt/root. Enable swap (swapon -v /dev/XXX). Start getting and compiling packages now :)

    Though, if you really wanna follow the whole process from A to Z, I do indeed recommend building n LFS system once. Just make sure you have a decent PC or a lot of time :)

    Cheers,
    Vlad

    EDIT: Actually, you say you're learning about Linux... If this is your first time installing any kind of linux, I'd still start from some seasoned distribution with more user-friendly installers ;)
  • lakshmipathi
    lakshmipathi Posts: 12
    Yes,I'm learning about linux internals ,I'll use LFS and also check the busybox. Thanks for useful links and details.
  • lakshmipathi
    lakshmipathi Posts: 12
    After nearly 20 hrs,now i have my distro minimal (LFS 6.4) :)
    But it has size of around 800MB. How to reduce it's size?
    Is it possible to create minimal distro less than 100MB
    or even 50 MB with LFS itself or should I use busybox?
  • atreyu
    atreyu Posts: 216
    lakshmipathi wrote:
    After nearly 20 hrs,now i have my distro minimal (LFS 6.4) :)
    But it has size of around 800MB. How to reduce it's size?
    Is it possible to create minimal distro less than 100MB
    or even 50 MB with LFS itself or should I use busybox?
    Removing all the documentation will buy you some space (like /usr/share/doc, /usr/share/man, etc.). Make sure you don't have source lying around somewhere, too.

    If you want to go uber-small ( <100MB ) , then I'd use busybox for all the utilities that I could get away with. Only if I needed some special feature of a utility that the busybox version doesn't offer (or there is no applet for it) would I then use the standard version. Also, look into uClibc, instead of glibc - it is geared for embedded systems. That will save you a lot of space, and Busybox works fine with it.
  • lakshmipathi
    lakshmipathi Posts: 12
    Thanks atreyu.
    Now i have mini-linux built from busybox with size 14MB B)
    Need to explore a bit with busybox and LFS ,hopefully uploaded and available for others soon :)

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