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- When building a target filesystem, it is desirable to not have to
- become root and then run 'mknod' a thousand times. Using a device
- table you can create device nodes and directories "on the fly".
- You can do all sorts of interesting things with a device table file.
- For example, if you want to adjust the permissions on a particular
- file you can just add an entry like:
- /sbin/foobar f 2755 0 0 - - - - -
- and (assuming the file /sbin/foobar exists) it will be made setuid
- root (regardless of what its permissions are on the host filesystem.
- Furthermore, you can use a single table entry to create a many device
- minors. For example, if I wanted to create /dev/hda and
- /dev/hda[0-15] I could just use the following two table entries:
- /dev/hda b 640 0 0 3 0 0 0 -
- /dev/hda b 640 0 0 3 1 1 1 15
- Device table entries take the form of:
- <name> <type> <mode> <uid> <gid> <major> <minor> <start> <inc> <count>
- where name is the file name, type can be one of:
- f: A regular file
- d: Directory
- c: Character special device file
- b: Block special device file
- p: Fifo (named pipe)
- uid is the user id for the target file, gid is the group id for the
- target file. The rest of the entries (major, minor, etc) apply only
- to device special files.
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