Baslinux mailing list

[3aoo-cvfd AT dea.spamcon.org]

sindi keesan wrote:
>
> > Yes, the loop version of BL3 has a small ramdisk
> > (to anchor the loop file).  IIRC it is less than 100kb.
>
> My partner wants to know more about this ramdisk.  

In order to use a loop file as the root filesystem,
you must first mount the partition where the loop
file resides.  fs.img (the BL3 loop file) resides
in the baslin directory on a DOS partition.  So
you need to mount the DOS partition and then mount
/baslin/fs.img.  This is done by a tiny filesystem
running in a ramdisk.

Have a look at boot.bat
--------------------------------------------------
loadlin zimage root=/dev/loop0 initrd=initfs.gz rw
--------------------------------------------------
It tells the kernel to unzip initfs.gz to a ramdisk 
and run it.  initfs is a small filesystem (containing 
a shell and a few necessary utilities/devices).  It 
automatically runs a script to mount the loop file 
at /dev/loop0.  The kernel then uses it as the root
filesystem (root=/dev/loop0).

Once the kernel is running on /dev/loop, the shell/
devices/utilities in initfs are redundant.  However, 
it is not possible to un-mount the ramdisk.  The 
ramdisk still contains the mountpoint for the DOS 
partition. You can't kill the ramdisk without killing 
access to fs.img 

> can he look at it?

Yes, the ramdisk is still mounted (at /initrd).  You
will find the executables in /initrd/bin and the devices
in /initrd/dev.  The script for mounting /dev/loop is
/initrd/linuxrc.

Cheers,
Steven

____________________________
http://www.basiclinux.com.ru