39  Recipe: Opt in to the C-7 signal/SDR pack

Field Value
Tool kailash (C-7 kailash-data.* SDR pack)
Section Administrator
Level easy
Time ~10 min + rebuild
Layer/Category CLASSIC / c-07-signal-sdr (opt-in)
Tags admin, data-packs, sdr, opt-in, gnuradio

39.1 Problem

Your AI/ML signal work needs the SDR substrate — GNU Radio’s DSP pipeline feeding model-training corpora, signal capture for audio/voice-model research — but no default image carries it: the C-7 rows are excluded from every ISO by construction because a multi-gig DSP stack has no business inside a ≤4 GB budget. You want the pack on ONE host, deliberately, and you want to verify exactly what landed.

39.2 Solution

Confirm the rows, opt in via the pack derivation, rebuild, verify:

# 1. See the C-7 rows the manifest declares (all status: data)
kailash info gnuradio      # software-defined radio DSP framework (software-only)
kailash info gqrx          # SDR receiver built on GNU Radio
kailash info hackrf-tools  # CLI utilities for HackRF hardware SDR platforms
kailash list --category c-07-signal-sdr
#    -> the opt-in six: gnuradio, gqrx, hackrf-tools, sox, librosa, pysox

# 2. Opt in via the pack derivation in your host configuration — a
#    deliberate config act, NOT a category enablement:
#    environment.systemPackages = [ kailash-data.sdr-tools ];
#    (packs ride kailash-data.* opt-in gating at the OS side; they never
#     ride a default profile)

# 3. Rebuild and switch
sudo nixos-rebuild switch

# 4. Verify what landed, software side first (no hardware needed)
gnuradio-config-info --version
grcc --version 2>/dev/null || echo "grcc present: $(command -v grcc)"
hackrf_info 2>/dev/null || echo "no HackRF attached — CLI present, device probe: PENDING"
gqrx 2>&1 | head -2 || true   # GUI starts (or reports missing display in a headless shell)

Expected output shape (abridged):

pack:    c-07-signal-sdr    (kailash-data.sdr-tools, opt-in DATA pack)
version: <nvfetcher rev>    (the lock/sources revision)
status:  data pack installed, default-OFF pack opted in
gnuradio-config-info --version
3.x.x
hackrf_info
Found HackRF...            # when hardware is attached
No HackRF boards found.    # when none is — the CLI is present either way

What success looks like:

  • the pack derivations are in the new system closure and the rebuild’s diff-closures shows ONLY the pack’s content (a category of attack or ops tooling snuck in is wrong — check what you actually declared)
  • gnuradio-config-info --version answers (software-only, works without any radio hardware)
  • hackrf_info runs; on a box WITH a HackRF it probes the device, on a box without it reports none found — the DSP-side research needs no RF hardware at all
  • a rebuild WITHOUT the opt-in line removes the pack entirely — the opt-out is the same declarative act in reverse

39.3 Discussion

  • Why SDR is a carve-out at all: Kailash deliberately is NOT Kali-for-networks — wifi/RF/Bluetooth attack tooling does not ship. SDR is the one exception, and the reason is stated in the spec: SDR is the substrate for AI/ML signal research — radio-based ML datasets, signal-capture corpora for audio/voice-model work, GNURadio’s DSP ecosystem feeding ML pipelines. The A-6 multi-modal attack surface (e.g. audio-voice-clone-injector) needs software DSP, not RF hardware stacks. Software-only: gnuradio/gqrx/hackrf-tools, plus the audio DSP support rows (sox, librosa, pysox).
  • Data-row delivery is the same discipline, different shape: these are status: data manifest rows — every fact (licence, source, update class) single-sourced like any tool — but the delivery is an opt-in derivation because of the size budget, and the opt-in never rides a default profile or a category toggle. kailash-data.* is the same mechanism as the wordlist packs; C-7 is simply the data-pack census category kept narrow by design (the spec’s §3.6 D7 decision records exactly this: a data-pack toggle, NOT a tool-category of record — the category count stays 31).
  • Size budget honesty: the ISO targets carry CI-enforced budgets (≤1.5/4/8/10 GB by target) and the budget check legs assert the heavies stay opt-in — texlive, gnuradio, the SDR/wordlist corpora. Opt in only where the work is: a headless DSP-training host can take the pack with no desktop in its closure.
  • Licensing note per row: GNU Radio GPLv3, Gqrx GPLv3+, HackRF tools GPLv2+ — all GPL-family and established; the caveat that matters here is the one every data row carries: whatever corpora you CAPTURE with this pack are your content, your licence decision. The manifest row does not establish capture-content licences.
  • Neighbour discipline: the same opt-in pattern covers every kailash-data.* pack — wordlists, texlive, the SDR six. The recipes’ PENDING discipline applies here too: the pack PATH layout on a live system is the derivation’s own record; the worked verification lands with the upkeep lane’s host checks.

39.4 See also

ref: manifest rows gnuradio/gqrx/hackrf-tools (+sox/librosa/pysox), c-07-signal-sdr — kailash-packages manifest - verified 2026-10-14. C-7 delivery-path statement from the spec (§2.2/§2.7/§3.6-D7, §7.1 budgets) + the guide’s images chapter. Pack PATH layout on a live host + the hardware-probe run: PENDING — the opt-in derivation shapes are the verified contract; the worked host check lands with the upkeep lane.