LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - General
User Name
Password
Linux - General This Linux forum is for general Linux questions and discussion.
If it is Linux Related and doesn't seem to fit in any other forum then this is the place.

Notices

Reply
 
Search this Thread
Old 01-13-2008, 01:17 AM   #1
unitedroad
LQ Newbie
 
Registered: Jan 2008
Posts: 8

Rep: Reputation: 0
Making a livecd without initrd or initramfs


Hi all,
I trying to make a livecd pretty much out of curiosity. I read online on wikipedia and some of the place through google that we need the initrd to provide the modules which we would need when the kernel boots up. But since putting those modules into the kernel image would have made the kernel too big , we put them together in the initrd. This initrd also provide the inital root file system to the kernel and therefore the kernel should have the support for the initrd's file system built into it.
So when the kernel bootloader hands over the control to the kernel along with the location of the initrd, the latter provides an initial root file system which is later mounted in a different location and later unmounted and the file system on the secondary media is mounted as the root file system.
However this brings two questions to my mind which seem to be interrelated :
1. Does the kernel really need a root file system?
2. Also, do we need to have the initrd file provide it ? Is it possible to have this support to be built right into the kernel?

If it is possible to boot linux without a root file system or without initrd then please also guide me on how we can do that.
 
Old 01-13-2008, 01:49 AM   #2
Drakeo
Senior Member
 
Registered: Jan 2008
Location: Urbana IL
Distribution: Slackware, Slacko,
Posts: 2,579
Blog Entries: 3

Rep: Reputation: 218Reputation: 218Reputation: 218
Go to first new post Making a livecd without initrd or initramfs

Quote:
Originally Posted by unitedroad View Post
Hi all,
I trying to make a livecd pretty much out of curiosity. I read online on wikipedia and some of the place through google that we need the initrd to provide the modules which we would need when the kernel boots up. But since putting those modules into the kernel image would have made the kernel too big , we put them together in the initrd. This initrd also provide the inital root file system to the kernel and therefore the kernel should have the support for the initrd's file system built into it.
So when the kernel bootloader hands over the control to the kernel along with the location of the initrd, the latter provides an initial root file system which is later mounted in a different location and later unmounted and the file system on the secondary media is mounted as the root file system.
However this brings two questions to my mind which seem to be interrelated :
1. Does the kernel really need a root file system?
2. Also, do we need to have the initrd file provide it ? Is it possible to have this support to be built right into the kernel?

If it is possible to boot linux without a root file system or without initrd then please also guide me on how we can do that.
I use the huge26.s kernel which is a bzimage. with lilo as my boot loader. no initrd image. slack has been doing this for years. when you make bzimage and install it copies the systems map over to the boot file the kernel loads and reads the map. that is why it is best to build your own kernel per system hardware.
 
Old 01-13-2008, 01:40 PM   #3
unitedroad
LQ Newbie
 
Registered: Jan 2008
Posts: 8

Original Poster
Rep: Reputation: 0
Quote:
Originally Posted by Drakeo View Post
I use the huge26.s kernel which is a bzimage. with lilo as my boot loader. no initrd image. slack has been doing this for years. when you make bzimage and install it copies the systems map over to the boot file the kernel loads and reads the map. that is why it is best to build your own kernel per system hardware.
bro can you guide me how I can do it or give me a link where I can research on it?
 
Old 01-14-2008, 02:40 AM   #4
Drakeo
Senior Member
 
Registered: Jan 2008
Location: Urbana IL
Distribution: Slackware, Slacko,
Posts: 2,579
Blog Entries: 3

Rep: Reputation: 218Reputation: 218Reputation: 218
long time ago before burning dvd's we would take like mandrake 8.0 or redhat 7 and do a limited install keeping everything under 700mb on the harddrive. then make a iso image of it then burn it to cd this way you could boot your system up and do critical repairs. today I just use a live cd like linux puppy 3.01 build what ever i need and then do a remaster live cd with every thing i need then I make a copy of my saved file and now i just carry two disk instead of a computer where ever I go I use some one elses computers and use my rewiteable dvd.to keep my stuff. I like doing it this way because I do not like how slow the usb flash drives are. i do carry a usb flash drive for back ups if needed. If I get to a windows computer with low ram then I use the usb flash drive as a swap file so puppy will have room to work. good day.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Initrd/initramfs problem during suse10.2 installation ph73nt Suse/Novell 3 08-09-2008 07:31 AM
Confusion PLEASE HELP!!!! Initrd + initramfs aroche Linux - General 2 08-18-2006 01:59 PM
difference between initrd and initramfs shrndegruv Linux - General 1 02-14-2006 12:03 AM
LiveCD just reboots pc after loading initrd phatrino Linux - General 1 10-02-2005 09:32 PM
Trying to understand how a boot loader handles initrd/initramfs/ramdisk ... cyril Linux - Software 0 04-08-2004 05:10 AM


All times are GMT -5. The time now is 01:10 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration