Making a raw disk file under Linux

In this example, I'll use 16MB...
old bios paramters according to the smartmedia format document are:
500 cylinders, 4 heads, 16 sectors/track
32000 logical sectors
(768 sectors are reserved to fix bad-sectors)

We're going to make two partitions :)

first, partition a disk file... (you might need to create it first)

sfdisk -uS -C 500 -H 4 -S 16 test.raw

lets define these partitions...

1: start=41 end=15999 size=15959 type=01 (FAT12) active
2: start=16000 end=31999 size=16000 type=83 (linux)

I didn't define a swap partition, but it might not be needed if using a ramdisk.
To define the partitions, type these lines:

41 15959 1 *
16000 16000 83
0 0
0 0

next, write the file and you can mount it using the looback device...
you must specify a byte-offset.
for the FAT12 partition it is 41*512=20992
and for the linux partition it is 16000*512=8192000

# if you can't mkfs a fat partition, format it using windows
#losetup /dev/loop0 test.raw -o 20992
#mkfs -t vfat -b block_size /dev/loop0 number_of_blocks
#mount -t vfat /dev/loop0 /mnt
#umount /mnt
#losetup -d /dev/loop0

losetup /dev/loop0 test.raw -o 8192000
mkfs -t ext2 -b 1024 /dev/loop0 8000		# the size must be correct
mount -t ext2 /dev/loop0 /mnt
umount /mnt
losetup -d /dev/loop0


I tried this under freebsd too, but had troubles with labeling the
virtual node device :/