thejayman77
ec82764bef
RTL (GS rasterizer, EE core stub, platform bridge, LPDDR4B path), sim regression (272 TBs), docs, and tooling. Copyrighted PS2 content (BIOS, game code, GS dumps, and all dump-derived textures/traces) is excluded via .gitignore and stays local. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2.7 KiB
2.7 KiB
FPGA Prior Art (Adjacent Consoles)
Codex correctly noted that no credible open-source HDL PS2 core surfaced. What did surface, and what Codex did not log, is a small cluster of PSX-on-FPGA projects. None are PS2, but they are the closest real-world templates for how a console-generation FPGA effort is scoped, built, and validated.
PSX_MiSTer — Robert Peip (FPGAzumSpass)
- Repo: https://github.com/MiSTer-devel/PSX_MiSTer
- Most feature-complete and widely-used PSX FPGA core.
- Author's prior work: GBA, Atari Lynx, WonderSwan cores on MiSTer.
The methodology is the useful part, not the RTL:
- Peip wrote his own cycle-accurate PSX software emulator first.
- Only then did he start the FPGA implementation, using the emulator as a continuous cycle-level golden model.
- Test vectors and traces were generated by the emulator and replayed into the RTL under simulation.
Why this matters for retroDE_ps2:
- This is the only known methodology that has produced a credible, accurate console-gen FPGA core from open-source work. Worth taking seriously as a starting playbook, even if the final plan diverges.
- It implies the reference-emulator choice (PCSX2 vs DobieStation vs Play! vs a purpose-built tiny one) is an architectural decision, not just a debugging nicety.
PS-FPGA
- Repo: https://github.com/PS-FPGA/ps-fpga
- Separate PSX-on-FPGA effort. Useful as a comparison point for project organization, module decomposition, and test harness layout.
pgate1/PlayStation_on_FPGA
- Repo: https://github.com/pgate1/PlayStation_on_FPGA
- Smaller / more hobbyist-scale PSX FPGA. Useful as a "minimum viable scaffold" reference if the project needs a leaner starting shape than PSX_MiSTer.
What these do not give us
- Zero usable RTL for EE, GS, VU0/VU1, VIF, GIF, SPU2, or the DMAC. The PSX's GPU is not a GS, its CPU is not an R5900, and it has no VU complex. Nothing transfers as a datapath.
- No GIF/GS packet path equivalent. This is a PS2-specific problem the PSX cores did not need to solve.
What they do give us
- A methodology template: golden-reference emulator → RTL with cycle-level trace comparison.
- A feel for scope discipline: PSX took Peip years with strong prior FPGA experience. PS2 is materially larger.
- Practical file layout, build, testbench, and host-integration patterns on MiSTer-class platforms.
Planning implication
Before Phase 0 lock, it is worth deciding explicitly whether retroDE_ps2 will follow the "cycle-accurate reference emulator first" pattern, adopt an existing emulator (PCSX2 or DobieStation) as the golden model, or take a different validation approach entirely. The answer changes Phase 1 scope.