A loopback device allows a normal disk file to be mounted as a filesystem. Depending on how much physical memory you have, using a loopback device may be preferable to using /dev/ram0 for building a root filesystem with Yard.
To use a loopback device you'll need to do the following:
Thanks to Roderich Schupp for some of this information.
ftp://ftp.win.tue.nl:/pub/linux/util/in the file
mount-2.5X.tar.gz
, where X is the latest
version letter.
mke2fs
with no arguments to see the version and option
information. If there is no ``-F'' option listed, you'll need a
newer version. mke2fs is included in the e2fsprogs package
available in:
sunsite.unc.edu:/pub/Linux/system/Filesystems/ext2/
To use the loopback device/file with Yard, simply:
/tmp/fsfile
. The file need not already
exist. Set $fs_size to its desired size.
create_loopback_file
or do it yourself with:
dd if=/dev/zero of=$device bs=1k count=$fs_size
and substitute your values for $device and
$fs_size.
insmod
loop
) into your kernel.
Yard may then be run with no further alterations.
Warning: When using a loopback device, occasionally the ext2
filesystem seems to get corrupted for no apparent reason. If you
start getting errors in the middle of make_root_fs
from sys() complaining that a directory doesn't exist, this may be
what is happening. I don't know why this happens and I can't
reproduce it consistently; however, unmounting, deleting and
re-creating the file seems to get rid of the problem.