A registry for V2_OS

[files]
  [<filename>]
    [modes]
      [<execution mode>]
        [enter]
          <register>=<value>
          [<value>]
            <size>=<value>
        [exit]
          <register>=<value>
          [<value>]
            <offset>=<value>
    [actions]
      [<action>]
        executable=<filename>
        mode=<execution mode>
[types]
  [<type>]
    [<action>]
      executable=<filename>
      mode=<execution mode>


[files] contains settings for individual files

<filename> is the full path and name of a file

[modes] contains settings for executing a file

<execution mode> is one of the following:
  - run
  - load
  - unload
  - any other value that can be displayed to the user and/or
    referenced in types/<type>/<action>/mode; [enter] and [exit] are
    allowed only for such custom execution modes

[enter] contains register values that the executable expects when it
is launched in this execution mode

<register> and <value> are one of the following:

  <register>               <value>

  al, cl, dl, bl,          an 8 bit integer or an ASCII character
  ah, ch, dh, bh

  ax, cx, dx, bx,          a 16 bit integer, two ASCII characters or a
  sp, bp, si, di           Unicode character

  eax, ecx, edx, ebx,      a 32 bit integer, 4 ASCII characters or 2
  esp, ebp, esi, edi       Unicode characters
    
  st0, st1, st2, st3,      an 80 bit float
  st4, st5, st6, st7

  mm0, mm1, mm2, mm3,      a 64 bit integer, 2 32 bit integers, 4
  mm4, mm5, mm6, mm7       16 bit integers, 8 8 bit integers or 2
                           32 bit floats
    
  xmm0, xmm1, xmm2, xmm3,  1 or 4 32 bit floats, 1 or 2 64 bit
  xmm4, xmm5, xmm6, xmm7   integers, 4 32 bit integers, 8 16 bit
                           integers or 16 8 bit integers
    
  es, ss, ds, fs           cs, ss, ds, gs
    
  <register> can also be a combination of a segment register and a
  general purpose register, like gs:ebx; it is then interpreted as a
  far pointer; if there are no other assignments for registers used
  here, they will be assigned some value and the data it points to is
  read-only; <value> is one of the following:
    - a text string
    - any other value; there must be a subkey with the same name that
      describes the actual data

[<value>] is a subkey describing structures pointed by registers

<size> is an integer describing the size of a value in bytes; <value>
is one of the following:
  - any of values for <register> described above, as long as the size
    matches; far pointers can have a size of 6 or 8; near pointers
    have a size of 4
  - a text string; it mey be truncated or padded with zeroes

[exit] describes register values when the executable exits; the format
is the same as for [enter]

[actions] describes which actions can pe performed on the file

<action> is a name of an action; it can be displayed to the user

executable determines the file to execute to perform the action; it
defaults to the file the action belongs to

mode determines the execution mode for the executable

[types] contains settings common to whole types of files

<type> describes a file type

<action> is the same as in files/<filename>/actions, except that
<action>/executable must be specified always

all entries can have special values and additional subkeys; following
special values are defined:
  - filename is the full name of the executable that performs an
    action
  - document is the full name of the file on which the action is
    performed