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1 | BFS FILESYSTEM FOR LINUX | ||
2 | ======================== | ||
3 | |||
4 | The BFS filesystem is used by SCO UnixWare OS for the /stand slice, which | ||
5 | usually contains the kernel image and a few other files required for the | ||
6 | boot process. | ||
7 | |||
8 | In order to access /stand partition under Linux you obviously need to | ||
9 | know the partition number and the kernel must support UnixWare disk slices | ||
10 | (CONFIG_UNIXWARE_DISKLABEL config option). However BFS support does not | ||
11 | depend on having UnixWare disklabel support because one can also mount | ||
12 | BFS filesystem via loopback: | ||
13 | |||
14 | # losetup /dev/loop0 stand.img | ||
15 | # mount -t bfs /dev/loop0 /mnt/stand | ||
16 | |||
17 | where stand.img is a file containing the image of BFS filesystem. | ||
18 | When you have finished using it and umounted you need to also deallocate | ||
19 | /dev/loop0 device by: | ||
20 | |||
21 | # losetup -d /dev/loop0 | ||
22 | |||
23 | You can simplify mounting by just typing: | ||
24 | |||
25 | # mount -t bfs -o loop stand.img /mnt/stand | ||
26 | |||
27 | this will allocate the first available loopback device (and load loop.o | ||
28 | kernel module if necessary) automatically. If the loopback driver is not | ||
29 | loaded automatically, make sure that your kernel is compiled with kmod | ||
30 | support (CONFIG_KMOD) enabled. Beware that umount will not | ||
31 | deallocate /dev/loopN device if /etc/mtab file on your system is a | ||
32 | symbolic link to /proc/mounts. You will need to do it manually using | ||
33 | "-d" switch of losetup(8). Read losetup(8) manpage for more info. | ||
34 | |||
35 | To create the BFS image under UnixWare you need to find out first which | ||
36 | slice contains it. The command prtvtoc(1M) is your friend: | ||
37 | |||
38 | # prtvtoc /dev/rdsk/c0b0t0d0s0 | ||
39 | |||
40 | (assuming your root disk is on target=0, lun=0, bus=0, controller=0). Then you | ||
41 | look for the slice with tag "STAND", which is usually slice 10. With this | ||
42 | information you can use dd(1) to create the BFS image: | ||
43 | |||
44 | # umount /stand | ||
45 | # dd if=/dev/rdsk/c0b0t0d0sa of=stand.img bs=512 | ||
46 | |||
47 | Just in case, you can verify that you have done the right thing by checking | ||
48 | the magic number: | ||
49 | |||
50 | # od -Ad -tx4 stand.img | more | ||
51 | |||
52 | The first 4 bytes should be 0x1badface. | ||
53 | |||
54 | If you have any patches, questions or suggestions regarding this BFS | ||
55 | implementation please contact the author: | ||
56 | |||
57 | Tigran A. Aivazian <tigran@veritas.com> | ||