Added another technique in the FAQ to show how space can be saved on the
root_fs by using the libraries from the initrd. Liav instigated this by
asking a question related to FAQ question 14, "So if I understand correctly,
it is not possible to copy libc from /dev/ram0 to /dev/ram1 before mounting
/dev/ram1 as / ?
Liav pointed out how Yard can make boot/root floppies with a compressed root
filesystem. Edited FAQ question 13 to correctly reflect how gz compressed
root filesystems may be booted without an initrd.
@ -490,23 +490,25 @@ and things should become more clear.
<br>
14. <ahref="#14">If libc is included in the boot disk, why is it needed in the root disk as well?</a>
<br>
15. <ahref="#15">There isn't enough room left on my 1440 floppy to make a Boot or Root disk. Is there any way to free up more space apart from reducing the size of the kernel?</a>
15. <ahref="#15">So if I understand correctly, it is not possible to copy libc from dev/ram0 to /dev/ram1 before mounting /dev/ram1 as / ?</a>
<br>
16. <ahref="#16">Last, but not least...the boot disk boots, waits for the root disk, and now fails. "Can't open console"??? or sth like this (I'm pretty tired right now, recheck later), which appears after "VFS:ext2fs was found..."</a>
16. <ahref="#16">There isn't enough room left on my 1440 floppy to make a Boot or Root disk. Is there any way to free up more space apart from reducing the size of the kernel?</a>
<br>
17. <ahref="#17">What are the kernel's drivers/fs that must be directly compiled, not as modules, except ext2, floppy? Could you attach your kernel's .config?</a>
17. <ahref="#17">Last, but not least...the boot disk boots, waits for the root disk, and now fails. "Can't open console"??? or sth like this (I'm pretty tired right now, recheck later), which appears after "VFS:ext2fs was found..."</a>
<br>
18. <ahref="#18">What is the root_fs_helper 2Mb file in the grootboot package?</a>
18. <ahref="#18">What are the kernel's drivers/fs that must be directly compiled, not as modules, except ext2, floppy? Could you attach your kernel's .config?</a>
<br>
19. <ahref="#19">
19. <ahref="#19">What is the root_fs_helper 2Mb file in the grootboot package?</a>
<br>
20. <ahref="#20">
Now the creation works, but actually the whole image is less than 1440k... Still, unclear to me is the purpose of the device/size in the main widget - is it only for the boot or also for the root disk? After all, the root fs image size has been already entered in the ARS.</a>
<br>
20. <ahref="#20">gBootRoot doesn't start because it can't locate Gtk.pm?</a>
21. <ahref="#21">gBootRoot doesn't start because it can't locate Gtk.pm?</a>
<br>
21. <ahref="#21">If you roll the floppy density counter down to 0 and then try go back up towards 1440 and 1722, you get very funny figures.</a>
22. <ahref="#22">If you roll the floppy density counter down to 0 and then try go back up towards 1440 and 1722, you get very funny figures.</a>
</a>
<br>
22. <ahref="#22">Changing from gz to bz2 compression for the boot image in the main section has no effect and gzip is still exectuted.</a>
23. <ahref="#23">Changing from gz to bz2 compression for the boot image in the main section has no effect and gzip is still exectuted.</a>
<br>
<P><aname="1"><b>What's the advantage of using this program?</b></a> <ahref="#FAQ">[back]</a></P>
@ -1126,20 +1128,20 @@ filesystem.</P>
<p>
If you are creating a boot disk in which the kernel knows where to
find the root filesystem and the root filesystem is not compressed with
gzip or bzip2 (i.e. a cramfs could be used), then nothing
else but a kernel is required
find the root filesystem and the root filesystem is
either compressed with gzip or not compressed (i.e. a cramfs could be used),
then nothing else but a kernel is required
assuming it is copied in a way that is starts at block 0 on the device
media, and then rdeved in such a way that it knows that the ramdisk and the
prompt
flag are on, i.e., rdev -r /dev/fd0 49152, and that the root filesystem starts
at block
0 on the other floppy.
However, the 2 disk compression method copies over a compressed (gz or bz2)
root filesystem
However, the 2 disk compression method was designed to uncompress bzip2
root filesystems as well as gzipped root filesystems from
to the second disk.  In order to boot /dev/fd0 from /dev/fd0 when
the root
filesystem is compressed with gzip or bzip2 the kernel has to
filesystem is compressed with bzip2 the kernel has to
mount the initial boot disk, and then after the new root disk is inserted it
uncompresses the root filesystem and then changes over to the real root
device,
@ -1207,7 +1209,35 @@ root. You can experiment with this by removing libc-*.so and
ld-*.so from a root filesystem which previously worked, first test it with
UML, and then try to boot it; in both cases it won't work.
<p><aname="15"><b>There isn't enough room left on my 1440 floppy to make a Boot or Root
<p><aname="15"><b>So if I understand correctly, it is not possible to copy libc from /dev/ram0 to /dev/ram1 before mounting /dev/ram1 as / ? </b></a> <ahref="#FAQ">[back]</a></p>
<p>
Actually, this could be accomplished before the change_root or pivot_root
call, however, there is a much easier solution.
Make a working root
filesystem, edit it either on a loop device as root, or on a different
ubd?=root_fs as any user from a Linux virtual machine.
Add an initrd
device to the mounted filesystem with <code>mknod initrd b 1 250</code>
<aname="18"><b>What is the root_fs_helper 2Mb file in the grootboot package?</b></a> <ahref="#FAQ">[back]</a></P>
<aname="19"><b>What is the root_fs_helper 2Mb file in the grootboot package?</b></a> <ahref="#FAQ">[back]</a></P>
<p>
@ -1311,7 +1341,7 @@ to unless Preserve Ownership is off.
<p>
<aname="19"><b>Now the creation works, but actually the whole image is less than
<aname="20"><b>Now the creation works, but actually the whole image is less than
1440k... Still, unclear to me is the purpose of the device/size in the
main widget - is it only for the boot or also for the root disk?
After all, the root fs image size has been already entered in the ARS.</b></a> <ahref="#FAQ">[back]</a></P>
@ -1339,11 +1369,11 @@ represents the mounted device provided in the main section.
<p>
<aname="20"><b>gBootRoot doesn't start because it can't locate Gtk.pm?</b></a> <ahref="#FAQ">[back]</a></P>
<aname="21"><b>gBootRoot doesn't start because it can't locate Gtk.pm?</b></a> <ahref="#FAQ">[back]</a></P>
<p>This program requires Gtk-Perl available from <ahref="http://www.perl.com/CPAN">CPAN</a>, <ahref="http://freshmeat.net/projects/gtk-perl">Freshmeat</a> or most GNU/Linux distributions.</p>
<p><aname="21"><b>If you roll the floppy density counter down to 0 and then try go back
<p><aname="22"><b>If you roll the floppy density counter down to 0 and then try go back
up towards 1440 and 1722, you get very funny figures.</b></a> <ahref="#FAQ">[back]</a></p>
<p>
@ -1390,7 +1420,7 @@ page up with the second button to 1440 and step with the first button to
<LI> Ctrl-V Paste from clipboard </LI>
</UL>
<p><aname="22"><b>Changing from gz to bz2 compression for the boot image in the main section has no effect and gzip is still exectuted.</b></a> <ahref="#FAQ">[back]</a></p>
<p><aname="23"><b>Changing from gz to bz2 compression for the boot image in the main section has no effect and gzip is still exectuted.</b></a> <ahref="#FAQ">[back]</a></p>
freesource
23 years ago