Mayhem

Mayhem is the community-maintained firmware for the PortaPack, the touchscreen-and-controls add-on board that turns a HackRF One software-defined radio into a self-contained, portable transceiver. Where a bare HackRF One needs a computer running GNU Radio or SDR software to do anything, a HackRF with a PortaPack running Mayhem is a standalone handheld: it receives, transmits, records, replays and decodes across a wide frequency range using only its own screen and jog-wheel. The firmware is developed in the open by a large group of contributors under the portapack-mayhem organization on GitHub.

This deep dive documents Mayhem at reference level: what it is and where it came from (this volume), its capabilities and the important fact that transmitting is legally regulated (Volume 2), how it is installed and updated (Volume 3), and how its SD card is laid out (Volume 4). The bench unit documented here — an HackRF One with a PortaPack, referred to in the owner’s notes as the porta unit — runs Mayhem.

1.1 What it is

The hardware underneath Mayhem is two boards. The HackRF One, from Great Scott Gadgets, is a half-duplex software-defined radio that covers roughly 1 MHz to 6 GHz with up to 20 million samples per second of bandwidth; its RF chain is an RFFC5072 mixer and a MAX2837 transceiver feeding a MAX5864 baseband converter, glued to an NXP LPC4320 microcontroller through a small CPLD. The PortaPack clips onto the HackRF’s expansion headers and adds a colour touchscreen, a jog-wheel and buttons, a real-time clock, and a microSD slot. Mayhem is the firmware that runs on the LPC4320 to drive all of that as an integrated instrument.

Because the HackRF is half-duplex, it either receives or transmits at a given instant, not both — a fact that shapes several of the apps in Volume 2. It is also a wideband, uncertified radio: it can be tuned almost anywhere in its range, but where it may lawfully transmit is a separate and much narrower question, addressed in Volume 2.

1.2 The Havoc → Mayhem lineage

Mayhem’s own README states the lineage plainly: it is a fork of the Havoc firmware, which was itself a fork of the original PortaPack firmware written by Jared Boone (sharebrained) as the add-on’s stock software.

• PortaPack (sharebrained) — the original firmware, focused on a clean, stable receiver and a well-engineered UI framework.
• Havoc (furrtek) — a fork that added a large number of transmit-capable and experimental applications, giving the firmware its offensive-tooling reputation.
• Mayhem (portapack-mayhem organization) — the continuation that merged the Havoc feature set back onto an actively maintained base and has carried development since. It is a community project with many contributors; the release and build infrastructure is maintained under the organization (the work is associated with the maintainer known as eried, whose Docker images and workflows drive the builds).

The practical result is that Mayhem is where new PortaPack apps land today; the sharebrained and Havoc repositories are of historical interest, and the Mayhem tree supersedes both for a current install.

1.3 Where this firmware runs — supported hardware

Mayhem targets the HackRF One paired with a PortaPack across its several revisions — H1, H2, H2+/H2M, H4 and the newer H4M (and clones of these) — plus the integrated OpenSourceSDRLab PortaRF, which bundles HackRF-class radio and a PortaPack-class front-end in one handheld and ships pre-flashed with Mayhem. The touchscreen generation and a few hardware details differ between revisions, and the project’s wiki carries a “which one to buy” page and an H1-versus-H2 comparison for anyone choosing hardware. For the purposes of this dive the firmware behaves as one product across the supported PortaPack revisions; where a feature needs a specific revision, the app itself says so. The table below is the canonical Firmware ↔ Device “runs on” matrix (the device names resolve to their Hack Tools deep dives):

Table 1 — device names resolve to their Hack Tools deep dives)

Board / device	SoC	Build target or variant	Feature level / notes	Where to get it
HackRF One + PortaPack H1	HackRF One + PortaPack (NXP LPC4320; RFFC5072 / MAX2837 / MAX5864 RF chain)	PortaPack H1; Mayhem dated nightly	First-generation PortaPack touchscreen and controls; a few hardware details differ from later revisions. The bench porta unit is a HackRF One with a PortaPack and runs Mayhem today.	Mayhem releases; HackRF One from Great Scott Gadgets, PortaPack from the usual vendors
HackRF One + PortaPack H2	HackRF One + PortaPack (NXP LPC4320)	PortaPack H2; Mayhem dated nightly	Second-generation PortaPack; the wiki’s H1-versus-H2 page covers the differences. Firmware behaves as one product; a feature needing a specific revision says so in-app.	Mayhem releases; PortaPack from the usual vendors
HackRF One + PortaPack H2+ / H2M	HackRF One + PortaPack (NXP LPC4320)	PortaPack H2+ / H2M; Mayhem dated nightly	H2 family with the metal-case / updated-display variants; same Mayhem build target.	Mayhem releases; PortaPack from the usual vendors
HackRF One + PortaPack H4	HackRF One + PortaPack (NXP LPC4320)	PortaPack H4; Mayhem dated nightly	Later PortaPack revision with a larger display generation; supported by current nightlies.	Mayhem releases; PortaPack from the usual vendors
HackRF One + PortaPack H4M	HackRF One + PortaPack (NXP LPC4320)	PortaPack H4M; Mayhem dated nightly	Newest supported PortaPack revision; metal-case H4 variant.	Mayhem releases; PortaPack from the usual vendors
HackRF One + PortaPack clone	HackRF One + PortaPack (NXP LPC4320)	clone of an H1–H4M revision; Mayhem dated nightly	Community and OEM clones of the supported revisions; each behaves as the revision it clones.	Mayhem releases; various clone vendors
OpenSourceSDRLab PortaRF	HackRF-class SDR + integrated PortaPack-class front-end (NXP LPC4320)	integrated handheld; Mayhem dated nightly	All-in-one HackRF-class handheld that bundles the PortaPack display, controls and battery; ships pre-flashed with Mayhem and updates from the same nightlies.	OpenSourceSDRLab (vendor); firmware from Mayhem releases

1.4 How this dive is organized

• Volume 1 (this volume) — what Mayhem is, its lineage, and the hardware it runs on.
• Volume 2 — the capability set: receive, transmit, capture and replay, decoders and utilities — and the regulatory limits on transmitting.
• Volume 3 — installation: prebuilt nightlies versus building from source, and the firmware update flow.
• Volume 4 — the SD card: its layout, the file formats, and data management.

1.5 Version and date note

This dive was written on 2026-09-16. Mayhem’s development is delivered as dated nightly releases — the latest at the time of writing was tagged nightly-tag-2026-09-16 — with formal tagged stable releases produced much less often; the last tagged stable was v2.0.1 (April 2024). The capability catalogue in Volume 2 reflects the application set documented on the project wiki as of September 2026, which matches the contemporaneous nightlies rather than the older stable tag. Apps are added and renamed frequently, so any single app list is a snapshot.

1.6 Related elsewhere

• Hack Tools → HackRF One, PortaRF (the Firmware ↔ Device “runs on” matrix).