NAME
        InitStruct - initialize memory from a table

   SYNOPSIS
        InitStruct(initTable, memory, size);
                   A1         A2      D0

        void InitStruct(struct InitStruct *, aptr, ulong);

   FUNCTION
        Clear a memory area, then set up default values according to
        the data and offset values in the initTable.  Typically only assembly
        programs take advantage of this function, and only with the macros
        defined in "exec/initializers.i".

        The initialization table has byte commands to

             |a    ||byte|      |given||byte|         |once         |
        load |count||word| into |next ||rptr| offset, |repetitively |
                    |long|

        Not all combinations are supported.  The offset, when specified, is
        relative to the memory pointer provided (Memory), and is initially
        zero.  The initialization data (InitTable) contains byte commands
        whose 8 bits are interpreted as follows:

        ddssnnnn
            dd  the destination type (and size):
                00  no offset, use next destination, nnnn is count
                01  no offset, use next destination, nnnn is repeat
                10  destination offset is in the next byte, nnnn is count
                11  destination offset is in the next 24-bits, nnnn is count
            ss  the size and location of the source:
                00  long, from the next two aligned words
                01  word, from the next aligned word
                10  byte, from the next byte
                11  ERROR - will cause an ALERT (see below)
          nnnn  the count or repeat:
             count  the (number+1) of source items to copy
            repeat  the source is copied (number+1) times.

        initTable commands are always read from the next even byte. Given
        destination offsets are always relative to the memory pointer (A2).

        The command %00000000 ends the InitTable stream: use %00010001 if you
        really want to copy one longword without a new offset.

        24 bit aptr not supported for 68020 compatibility -- use long.

   INPUTS
        initTable - the beginning of the commands and data to init
                Memory with.  Must be on an even boundary unless only
                byte initialization is done.  End table with "dc.b 0"
                or "dc.w 0".
        memory - the beginning of the memory to initialize.  Must be
                on an even boundary if size is specified.
        size - the size of memory, which is used to clear it before
                initializing it via the initTable.  If Size is zero,
                memory is not cleared before initializing.

                size must be an even number.

    SEE ALSO
        exec/initializers.i