fromhd= support a la knoppix (e.g. boot from compressed image on hard drive or CF)

[togo at of.net (Tony Godshall)]

Hi

I was wondering if there are any plans to include functionality like
Knoppix' and DSL's fromhd=.  Some people call this a "poor man's
install" and others call it a "frugal install"

In particular, I'd like to be able to have grub on my hard drive or
usb set to boot from a compressed image on the hard drive.

Benefits:

1. hard-drive-based installation that is functionally identical to live-CD

2. less space taken on hard drive- making it more suitable for
CF-based embedded systems

3. live-CD technology results in reduction in hard drive writing-
again, more suitable for flash-based systems

Here's how it works in Knoppix...

-- start quote --

Test remastered version without creating cloop file/iso

i use a setup similar to knoppix terminal server to test the
remastered files without having to recreate a cloop image every time:
the remastered files live in an ext2 filesytem in a loopfile
(knoppix_loop) mounted rw (this is where i chroot in). when i want to
test the current setup, i have another machine network boot and use
the files from the loopfile directly (needs another miniroot.gz). See
User:Ml#dev_setup

If you want to use only one machine, you'll have to reboot (or use
qemu) and use the "loopfile" and "fromhd" cheatcodes (see
User:Ml#miniroot_changes). For example, this is what my grub boot
entry looks like:

title           Remastered Knoppix
root            (hd0,0)
kernel          /boot/myknoppix/vmlinuz fromhd=/dev/hda4
loopfile=/samba/share/isos/knoppix_loop lang=us ramdisk_size=100000
init=/etc/init apm=power-off nomce vga=791 quiet BOOT_IMAGE=knoppix
initrd          /boot/myknoppix/miniroot.gz


 Booting Knoppix images with GRUB

    * First copy /boot off the Knoppix cd to your boot partition (or
even your dos partition). I named mine boot.knoppix

Copy the /KNOPPIX directory to your root directory* of any hard disk.
You may place it somewhere other than the boot partition (ext2/3,
reiserfs, vfat are supported).

...

title KNOPPIX
        root   (hd0,0)
        kernel /boot.knoppix/isolinux/linux 2 fromhd=/dev/hda4 lang=us
        initrd /boot.knoppix/isolinux/minirt.gz

    * notice the fromhd parameter: it's the location of the /KNOPPIX directory
    * reboot and have fun.

--end quote--

The quote is from...
  http://www.knoppix.net/wiki/Knoppix_Remastering_Howto#Test_CD_Image_Without_Burning_a_CD

--
Tony Godshall (g)