Kernel Support for miscellaneous (your favourite) Binary Formats v1.1
       =====================================================================
  
  This Kernel feature allows you to invoke almost (for restrictions see below)
  every program by simply typing its name in the shell.
  This includes for example compiled Java(TM), Python or Emacs programs.
  
  To achieve this you must tell binfmt_misc which interpreter has to be invoked
  with which binary. Binfmt_misc recognises the binary-type by matching some bytes
  at the beginning of the file with a magic byte sequence (masking out specified
  bits) you have supplied. Binfmt_misc can also recognise a filename extension
  aka '.com' or '.exe'.
  
  First you must mount binfmt_misc:
  	mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc 
  
  To actually register a new binary type, you have to set up a string looking like

  :name:type:offset:magic:mask:interpreter:flags (where you can choose the ':'
  upon your needs) and echo it to /proc/sys/fs/binfmt_misc/register.

  Here is what the fields mean:
   - 'name' is an identifier string. A new /proc file will be created with this

     name below /proc/sys/fs/binfmt_misc; cannot contain slashes '/' for obvious
     reasons.

   - 'type' is the type of recognition. Give 'M' for magic and 'E' for extension.
   - 'offset' is the offset of the magic/mask in the file, counted in bytes. This

     defaults to 0 if you omit it (i.e. you write ':name:type::magic...'). Ignored
     when using filename extension matching.

   - 'magic' is the byte sequence binfmt_misc is matching for. The magic string

     may contain hex-encoded characters like \x0a or \xA4. Note that you must
     escape any NUL bytes; parsing halts at the first one. In a shell environment
     you might have to write \\x0a to prevent the shell from eating your \.

     If you chose filename extension matching, this is the extension to be
     recognised (without the '.', the \x0a specials are not allowed). Extension

     matching is case sensitive, and slashes '/' are not allowed!

   - 'mask' is an (optional, defaults to all 0xff) mask. You can mask out some
     bits from matching by supplying a string like magic and as long as magic.

     The mask is anded with the byte sequence of the file. Note that you must
     escape any NUL bytes; parsing halts at the first one. Ignored when using
     filename extension matching.

   - 'interpreter' is the program that should be invoked with the binary as first
     argument (specify the full path)
   - 'flags' is an optional field that controls several aspects of the invocation

     of the interpreter. It is a string of capital letters, each controls a
     certain aspect. The following flags are supported -
        'P' - preserve-argv[0]. Legacy behavior of binfmt_misc is to overwrite
              the original argv[0] with the full path to the binary. When this
              flag is included, binfmt_misc will add an argument to the argument
              vector for this purpose, thus preserving the original argv[0].
              e.g. If your interp is set to /bin/foo and you run `blah` (which is
              in /usr/local/bin), then the kernel will execute /bin/foo with
              argv[] set to ["/bin/foo", "/usr/local/bin/blah", "blah"].  The
              interp has to be aware of this so it can execute /usr/local/bin/blah
              with argv[] set to ["blah"].

        'O' - open-binary. Legacy behavior of binfmt_misc is to pass the full path
              of the binary to the interpreter as an argument. When this flag is
              included, binfmt_misc will open the file for reading and pass its
              descriptor as an argument, instead of the full path, thus allowing

              the interpreter to execute non-readable binaries. This feature
              should be used with care - the interpreter has to be trusted not to
              emit the contents of the non-readable binary.

        'C' - credentials. Currently, the behavior of binfmt_misc is to calculate
              the credentials and security token of the new process according to
              the interpreter. When this flag is included, these attributes are
              calculated according to the binary. It also implies the 'O' flag.
              This feature should be used with care as the interpreter
              will run with root permissions when a setuid binary owned by root
              is run with binfmt_misc.

        'F' - fix binary.  The usual behaviour of binfmt_misc is to spawn the
        	    binary lazily when the misc format file is invoked.  However,
  	    this doesn't work very well in the face of mount namespaces and
  	    changeroots, so the F mode opens the binary as soon as the
  	    emulation is installed and uses the opened image to spawn the
  	    emulator, meaning it is always available once installed,
  	    regardless of how the environment changes.

  
  
  There are some restrictions:

   - the whole register string may not exceed 1920 characters

   - the magic must reside in the first 128 bytes of the file, i.e.
     offset+size(magic) has to be less than 128
   - the interpreter string may not exceed 127 characters
  
  To use binfmt_misc you have to mount it first. You can mount it with
  "mount -t binfmt_misc none /proc/sys/fs/binfmt_misc" command, or you can add
  a line "none  /proc/sys/fs/binfmt_misc binfmt_misc defaults 0 0" to your
  /etc/fstab so it auto mounts on boot.
  
  You may want to add the binary formats in one of your /etc/rc scripts during
  boot-up. Read the manual of your init program to figure out how to do this
  right.
  
  Think about the order of adding entries! Later added entries are matched first!
  
  
  A few examples (assumed you are in /proc/sys/fs/binfmt_misc):
  
  - enable support for em86 (like binfmt_em86, for Alpha AXP only):
    echo ':i386:M::\x7fELF\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x03:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfb\xff\xff:/bin/em86:' > register
    echo ':i486:M::\x7fELF\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x06:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfb\xff\xff:/bin/em86:' > register
  
  - enable support for packed DOS applications (pre-configured dosemu hdimages):
    echo ':DEXE:M::\x0eDEX::/usr/bin/dosexec:' > register
  
  - enable support for Windows executables using wine:
    echo ':DOSWin:M::MZ::/usr/local/bin/wine:' > register
  
  For java support see Documentation/java.txt
  
  
  You can enable/disable binfmt_misc or one binary type by echoing 0 (to disable)
  or 1 (to enable) to /proc/sys/fs/binfmt_misc/status or /proc/.../the_name.
  Catting the file tells you the current status of binfmt_misc/the entry.
  
  You can remove one entry or all entries by echoing -1 to /proc/.../the_name
  or /proc/sys/fs/binfmt_misc/status.
  
  
  HINTS:
  ======
  
  If you want to pass special arguments to your interpreter, you can
  write a wrapper script for it. See Documentation/java.txt for an
  example.
  
  Your interpreter should NOT look in the PATH for the filename; the kernel
  passes it the full filename (or the file descriptor) to use.  Using $PATH can
  cause unexpected behaviour and can be a security hazard.

  Richard Günther <rguenth@tat.physik.uni-tuebingen.de>