system the most common are coff and elf binary formats in both formats the program is represented as a sequence of operation codes and their operands in the bd the two stage parsing is used the first stage u2014 the conversion of the binary code into text representation is done by the software distributed with the binutils linux package the second stage u2014 the conversion from text to the in memory structure is implemented as a set of a parsing rules for lex and yacc u2014 software libraries to generate parsers based on a parsing rules text representation to add new instructions a line describing the instruction must be added into the file defining the parsing rules this is simpler then parsing instructions in a dedicated parser and therefore allows more efficient versatile and reliable implementation additionally the parsing engine based on lex and yacc could be quickly extended to support different platforms and instruction sets the preferred embodiment is implemented on unix platform where common format for representing assembly instructions is an at amp t format the intel assembly format is the format used on windows platforms the at amp t and intel formats are equivalent an assembler instruction in at amp t syntax has the form operand could be an explicit value a reference to memory or register the opcode defines the size of the operands it can be 8 bit 16 bit 32 bit 64 bit instruction.