---
language: [en]
pretty_name: Kernel and MCU-OS C pool (code + design docs)
task_categories: [text-generation]
tags: [code, c, linux-kernel, rtos, embedded, domain-adaptation]
configs:
- config_name: default
  data_files:
  - {split: train, path: "data/train-*.parquet"}
  - {split: heldout, path: "data/heldout-*.parquet"}
---
# Kernel and MCU-OS C pool

Unmixed pool of C/assembly source and design documentation for domain-adaptive training of a kernel-level coding model.
Apply the mix at sampling time using the `bucket` column.

| bucket | content | est. tokens (train) |
|---|---|---|
| mcu | FreeRTOS, Zephyr, NuttX, RIOT, CMSIS, xv6, Contiki-NG, RT-Thread, U-Boot, OpenSBI, seL4, libopencm3 | ~116.5M |
| linux_gpu | drivers/gpu, video, accel | ~25.3M |
| linux_cpu | arch/*, cpufreq, cpuidle, irqchip, clocksource, perf, firmware | ~7.7M |
| linux_core | kernel, mm, fs, net, block, pci, usb, dma, include/linux ... | ~45.2M |
| docs | Linux Documentation/, Zephyr doc/, NuttX Documentation/, U-Boot doc/, RISC-V ISA manual, seL4 docs | ~14.4M |

Token counts are byte-based estimates (3.6 bytes/token), not tokenizer counts.

## Columns
`text`, `path`, `bucket`, `source`, `spdx` (per-file SPDX tag if present, else the repository licence), `repo_license`, `commit` (upstream commit the file came from), `def_heavy` (file is >60% `#define` lines, typically register headers; consider down-sampling), `n_bytes`.

## Splits
`heldout` holds about 2% of directories (hash of the first 5 path components), so no directory appears in both splits.
Caution: heldout is skewed toward `mcu` (about 19 percent of files in the pool but most of heldout tokens); evaluate per bucket.

## Filters
Exact dedup (whitespace-normalised SHA-1 only; no near-duplicate removal), 300 B to 120 KB per code file (500 B to 150 KB for docs), generated-file and hex-table filters, test/sample/scripts/dts/board paths skipped for code, non-ASCII ratio limits.

## Licences (read before use)
Content keeps its upstream licences, mostly GPL-2.0 variants (Linux, U-Boot, seL4), Apache-2.0 (Zephyr, NuttX, RT-Thread, CMSIS), MIT, BSD, LGPL, and CC-BY-4.0 (RISC-V ISA manual). Per-file SPDX tags are preserved in `spdx`; see `LICENSES.json` for the upstream commit and licence files per documentation source.
Whether training on GPL code makes a model a derivative work is legally unsettled. This dataset does not resolve that; you are responsible for your use and for the licence terms when redistributing the data or derived weights.

## Not included
Commercial textbooks. Open-licensed books (e.g. LDD3, Mastering the FreeRTOS Real Time Kernel) are not yet added; their licences must be verified at source first.