# Rosenblatt

**Codename:** Frank Rosenblatt built the Mark I Perceptron in 1958 — the first
hardware neural network (400 photocells, stepper-motor-tunable analog weights).
This project lights up the RK3588 NPU on mainline Linux, so the OSS world
finally owns the silicon-side of inference on that chip.

**Scope (Phase 1):** small LLM running CPU + NPU mix on `boltzmann` (Rock 5
ITX+, RK3588, 32 GB DDR4). Backend: `llama.cpp` with a new `rknpu` device that
offloads the heavy GEMM (matmul in attention + FFN) to the NPU's INT8 path
while leaving dequant / RoPE / softmax / sampling / embedding lookup on the
A76 NEON cores.

**Target model (Phase 1):**
`qwen2.5-1.5B-instruct` Q4_K_M GGUF. Fits in NPU's accessible memory
budget, has chat tuning, public license. Stretch: `qwen2.5-3B`,
`gemma3-2B`.

**Out of scope (Phase 1, capture separately if pursued):**
- Vision helper (object detection / OCR / face-blur) — different op mix,
  re-scope after Phase-1 numbers
- RKNPU vendor SDK adoption — we want mainline-clean, not vendor-blob
- Other Rockchip NPUs (RK3576 has the same NPU IP block — should port for
  free once the RK3588 path lands, but defer until Phase-1 closes)

**Not goal: parity with rknn-llm vendor stack on day 1.** Vendor has
hand-tuned tensor layouts + quantization; we'll be slower at first. Goal
is *credible* — defined as ≥1 tok/s sustained on qwen-1.5B Q4 with the
NPU actually doing the bulk of the GEMM work. The number itself isn't the
point; the open path to it is.

---

## Phases (9 + 1 loop)

| # | Phase | Deliverable |
|---|---|---|
| 1 | **Substrate** | Audit mainline NPU driver state (Tomeu Vizoso's rknpu / DRM-accel series); `/dev/accel/*` probe on boltzmann; running kernel + module inventory. `docs/npu-mainline-status.md` snapshot. |
| 2 | Formulate | Pick the exact matmul shape that fits the NPU's tile-MAC array. Identify the smallest-possible op-set llama.cpp can offload. |
| 3 | Analyze | Read the RKNPU2 SDK + Tomeu's rknpu uAPI to learn: register layout, DMA tensor format, INT8 quant scheme. Don't lift code — extract the spec. |
| 4 | Baseline | llama.cpp pure-CPU tok/s on boltzmann for qwen-1.5B Q4_K_M. Three runs, median. Reproducible bench script in `benchmarks/`. |
| 5 | Plan | rknpu backend interface design — where it plugs into ggml's compute graph; memory mapping strategy (dmabuf vs userptr); fallback path. |
| 6 | Review | Janet (ARM/DRM specialist agent) reviews the NPU register-write + DMA fence strategy. Cold-eyes pass. |
| 7 | Implement | rknpu ggml backend skeleton + first INT8 matmul. Bit-exact against CPU reference (Q4_K dequant + fp32 matmul). |
| 8 | Verify | Compare tok/s vs Phase-4 baseline. Profile: % time in NPU vs % in CPU vs % stalled on DMA. |
| 9 | Closing | Writeup at `dokuwiki.reauktion.de/doku.php?id=rosenblatt`. Benchmarks rendered. Send-to-upstream cover letter draft if quality is there. |
| 10 | Memory | `project_rosenblatt.md` in claude-memory: what worked, what to avoid for the next NPU campaign (RK3576 port). |

Per `feedback_dev_process.md`: rewind to Phase 1 on blocker, Phase 4 on
direction change, Phase 0 on scope change.

---

## Repo layout

```
rosenblatt/
├── README.md              this file
├── TODO.md                rolling punch-list
├── docs/
│   ├── npu-mainline-status.md    Phase-1 audit
│   ├── architecture.md           CPU+NPU split, ggml backend shape
│   └── phases.md                 per-phase log (analog to ~/src/bin/phases/)
├── kernel/                       mainline-bound patches (DT bindings, rknpu driver tweaks)
├── userspace/
│   ├── npu-probe/                smallest-possible "open device + run trivial matmul" sanity
│   └── llm-runtime/              llama.cpp fork with rknpu backend
├── fleet/
│   └── boltzmann.yaml            host manifest (kernel + NPU driver pin, baseline measurement)
└── benchmarks/                   reproducible bench scripts + recorded results (JSON + plots)
```

---

## Host

Primary: **boltzmann** (Rock 5 ITX+, RK3588, 32 GB DDR4-2666, NVMe rootfs).
- Already runs mainline ~v7.0 with most peripheral drivers working.
- Has the Quark UEFI / Neutron kernel stack — NPU is the next missing peripheral.
- Other RK3588 hosts (`ampere` = CoolPi GenBook) come later for port-validation.

Why not `ampere`: laptop, intermittent power, in-use for other campaigns.
Boltzmann is always-on with 32 GB headroom — right substrate for kernel
hacking with serial-console fallback (when [Quark](https://git.reauktion.de/marfrit/quark) exposes one).

---

## Codename rationale

Rosenblatt's Mark I was custom analog hardware doing fixed-function matmul-
adjacent work (weighted-sum + threshold), with weights tunable per slot via
mechanical control. The RK3588 NPU is fixed-function INT8 matmul/conv hardware
with weights loaded per inference. Same shape, 67 years later, with the same
"how do we drive this thing from a general-purpose computer?" problem. The
1958 paper's answer was: build a control panel. The 2026 answer is: a DRM
accelerator driver + a userspace runtime that maps tensor ops to MMIO + DMA.
We're writing the second half.

---

## Status

| Phase | State | Date |
|---|---|---|
| 0 — bootstrap | done | 2026-05-19 |
| 1 — substrate audit | done | 2026-05-19 |
| 2 — formulate | open | |
| 3..10 | pending | |

Phase-1 closeout: `docs/phases.md` + `docs/npu-mainline-status.md`.
Headline: mainline driver name is **`rocket`** (not `rknpu`); it's
already shipped in boltzmann's kernel as a built module. Phase-2
unblock is small (DT enable + IOMMU v1.0 mitigation + modprobe),
not a driver port.