Edigen - Emulator Disassembler Generator

Edigen is a command-line tool which generates Java source code of:

• instruction decoder of an emulator
• and disassembler

from a text file written in its own domain-specific language.

Writing disassemblers and emulator instruction decoders by hand is tedious and error-prone. The code is often unreadable and unmaintainable. Edigen takes a file containing the description of instruction formats, operation codes and mnemonics as an input. It generates Java classes compatible with emuStudio platform, i.e. implementing interfaces from emuLib.

For system architecture and detailed technical documentation, visit https://www.emustudio.net/edigen/

Usage

The best way to use Edigen either with:

• edigen-gradle-plugin
• or edigen-maven-plugin

Alternative way is to manually execute Edigen through a command-line interface. To see all command line options, execute the Edigen JAR without any arguments.

Specification format

Edigen files have the .eds extension and are split into a decoder and a disassembler part, separated by %%. A small taste:

# decoder
root: instruction, data;

instruction =
    "add": 0xE dst_reg(2) src_reg(2) |
    "sub": 0xF dst_reg(2) immediate(10);

data =
    data: data(32);

src_reg, dst_reg =
    "X": 00 |
    "Y": 01;

%%

# disassembler
"%s %s, %s" = instruction dst_reg src_reg;
"%s %s, %d" = instruction dst_reg immediate;
"%0x"       = data;

For the full syntax and semantics, see the EDS Language chapter of the Edigen documentation (also published at https://www.emustudio.net/edigen/).