DEFINITION MODULE Memory ;

(* MC64 virtual machine memory: a single linear byte array.
   Machine addresses (IP, SP, FP, GP, OFP) are LONGCARD offsets
   into this array.  No host allocation is performed. *)

EXPORT QUALIFIED MaxMem, Init, ArenaBase, TopOfMemory, heapPointer,
  ReadByte, WriteByte, ReadSlot, WriteSlot, ReadWord, WriteWord,
  ReadLong, WriteLong, CopyBytes, FillBytes, LoadImage ;

CONST MaxMem = 16777216 ;  (* 16 MiB *)

VAR heapPointer: LONGCARD ;

PROCEDURE Init ;
PROCEDURE ArenaBase () : LONGCARD ;
PROCEDURE TopOfMemory () : LONGCARD ;

PROCEDURE ReadByte (a: LONGCARD) : CARDINAL ;
PROCEDURE WriteByte (a: LONGCARD; b: CARDINAL) ;
PROCEDURE ReadSlot (a: LONGCARD) : LONGCARD ;
PROCEDURE WriteSlot (a: LONGCARD; v: LONGCARD) ;
PROCEDURE ReadWord (a: LONGCARD) : CARDINAL ;
PROCEDURE WriteWord (a: LONGCARD; v: CARDINAL) ;
PROCEDURE ReadLong (a: LONGCARD) : LONGINT ;
PROCEDURE WriteLong (a: LONGCARD; v: LONGINT) ;

PROCEDURE CopyBytes (src, dst: LONGCARD; n: LONGCARD) ;
PROCEDURE FillBytes (dst: LONGCARD; n: LONGCARD; b: CARDINAL) ;
PROCEDURE LoadImage (VAR data: ARRAY OF CHAR; off: CARDINAL; dst: LONGCARD; n: CARDINAL) ;

END Memory.