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phoenix |
BFS FILESYSTEM FOR LINUX
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The BFS filesystem is used by SCO UnixWare OS for the /stand slice, which
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usually contains the kernel image and a few other files required for the
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boot process.
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In order to access /stand partition under Linux you obviously need to
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know the partition number and the kernel must support UnixWare disk slices
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(CONFIG_UNIXWARE_DISKLABEL config option). However BFS support does not
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depend on having UnixWare disklabel support because one can also mount
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BFS filesystem via loopback:
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# losetup /dev/loop0 stand.img
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# mount -t bfs /dev/loop0 /mnt/stand
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where stand.img is a file containing the image of BFS filesystem.
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When you have finished using it and umounted you need to also deallocate
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/dev/loop0 device by:
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# losetup -d /dev/loop0
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You can simplify mounting by just typing:
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# mount -t bfs -o loop stand.img /mnt/stand
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this will allocate the first available loopback device (and load loop.o
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kernel module if necessary) automatically. If the loopback driver is not
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loaded automatically, make sure that your kernel is compiled with kmod
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support (CONFIG_KMOD) enabled. Beware that umount will not
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deallocate /dev/loopN device if /etc/mtab file on your system is a
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symbolic link to /proc/mounts. You will need to do it manually using
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"-d" switch of losetup(8). Read losetup(8) manpage for more info.
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To create the BFS image under UnixWare you need to find out first which
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slice contains it. The command prtvtoc(1M) is your friend:
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# prtvtoc /dev/rdsk/c0b0t0d0s0
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(assuming your root disk is on target=0, lun=0, bus=0, controller=0). Then you
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look for the slice with tag "STAND", which is usually slice 10. With this
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information you can use dd(1) to create the BFS image:
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# umount /stand
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# dd if=/dev/rdsk/c0b0t0d0sa of=stand.img bs=512
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Just in case, you can verify that you have done the right thing by checking
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the magic number:
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# od -Ad -tx4 stand.img | more
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The first 4 bytes should be 0x1badface.
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If you have any patches, questions or suggestions regarding this BFS
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implementation please contact the author:
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Tigran A. Aivazian
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