# rtl/platform

retroDE-specific platform integration. Matches `docs/contracts/platform.md`.

## Wave 1 contents

- `platform_video_stub.sv` — free-running raster generator. Default VGA
  640x480 timing (overridable per-testbench to tiny values for fast sim).
  Takes `bg_{r,g,b}` from `gs_stub` and flood-fills the active region.
  Emits one `EV_MODE` per completed frame so testbenches can count frames
  without sampling raw video.

## Scope boundary

This directory owns:

- clock/reset sequencing entry points,
- retroDE-facing video and audio adaptation,
- HPS bridge plumbing (future),
- top-level wrappers not belonging inside PS2 subsystems.

It does **not** own GS/PCRTC semantics (that's `rtl/gif_gs/`), SPU2 audio
synthesis (`rtl/spu2/`), or any PS2 register behavior.

## Replacement path

`platform_video_stub` stays as the platform adaptation layer. What changes
is the upstream pixel source: Wave 1 → flat BGCOLOR from `gs_stub`,
later waves → fuller GS/PCRTC output including framebuffer scan-out.
