Skip to content

Latest commit

 

History

History
55 lines (42 loc) · 2.17 KB

README.md

File metadata and controls

55 lines (42 loc) · 2.17 KB
Raw

Dreamcast Emulator

Main goal of this project is to create a Dreamcast emulator supporting dynarec, HLE and, perhaps, static binary recompilation. The main target of this is the game Soul Calibur, which is one of the best fight games ever developed.

Goal and approach

The short term goal stands on creating an efficient sh7750h emulator. To do so the following approach is taken:

  • Create sh7750h disassembler and compare this with public disassemblers
  • Implement the sh775h interpreter and cross-check functionality using programs that do not use system calls, hardware, etc... just basic data processing with program input/output
  • Refactor the interpreter to apply dynamic recompilation techniques
  • Implement HLE to execute sh7750h applications that make use of the libc so they run under Mac/Linux using high level resources like syscalls, printf, memory allocation, etc...

From that point on the real Dreamcast development would start trying to reuse the emulator for Dreamcast emulation. More information have to be gathered first before tackling that task.

How to compile it

For now compilation is quite simple:

$ make

That should generate the opcode generation tool (sh4opgen) and the disassembler (sh4disassembler).

To clean all the generated artifacts:

$ make clean

Opcode generation tool

The opcode generation tools is a helper tool used to generate the following files:

  • sh4opcode.h
  • sh4opcodeLUT.c
  • sh4opcodedis.c
  • sh4opcodeemu.c

To generate those files the file sh4opcode.def is used. That files has the definition of all opcodes for the sh7750h. Please check the file for more information on the format. Then the tool takes the file and generates a lookup table to decode any 16-bit opcode into the corresponding processing function.

There are 2 lookup tables, one for disassembling and the other one for interpreting. The disassembler tool makes use of this tables to perform its task.

Disassembler

The disassembler, at this stage, takes a binary files with 16-bit opcodes and decodes them, printing out the disassembler mnemonics. In the future it will support ELF format and smarter static code parsing to determine which parts are code and which ones data.