fx-init — the running fixpoint-linux system

The M4 init system for fixpoint-linux: a Dhall-specified, self-hosting Linux system. This repo is self-contained — it owns the entire "running system" surface and composes the org's proven components as vendored submodules:

• fx-init — a lean PID1/supervisor (Zig, zig/zig-out/bin/fx-init). Reads the CURRENT store generation, performs boot-status + roll-forward rollback, execs dhake on the generation's buildfile to materialize the rootfs (/etc, /bin symlinks, /run), starts and supervises services (readiness + health, restart policy, backoff), and maintains the live runtime datalog DB. It is the sole writer of runtime state.
• fx-activate — build-time activation. Evaluates config.dhall (dhall-c), computes the dependency closure, emits a per-generation dhake buildfile, writes generation facts, and publishes a store snapshot (one generation).
• fxctl — the datalog control/query plane. Queries any live relation (joining the immutable store DB), hybrid log search, and control (start|stop|restart| activate|rollback|shutdown|probe) — all datalog-framed over /run/fx/control.sock.
• fx_probe / fx_log (Zig modules) — the init-hosted probe loop (process/fs/file/device/ kernel/net/env from /proc,/sys) and the compact DAFSA-interned service log DB.

Components this composes (submodules in vendor/)

Component	Role
fxstore	the content-addressed store (store/closure/snapshot primitives)
datalog-dafsa	the Datalog/DAFSA engine (runtime + log relations, hybrid search)
dafsa	compact shared-suffix store (log message interning)
dhake	the Dhall build runner (rootfs materialization at boot)
dhall-c	the config language evaluator (activation)

Build (Zig)

./vendor/dhake/dhake.com            # default target: all — Zig build + tests
./vendor/dhake/dhake.com fx-init    # the Zig build (also fx-activate/fxctl/fakesvc)
./vendor/dhake/dhake.com test       # zig unit tests + the 7 diff harnesses

The production binaries are the Zig port (zig/build.zig -> zig/zig-out/bin/). The former C oracles were removed after the live differential harnesses verified the ports byte-identical; the harnesses now pin that verified behavior under zig/golden/ (see each zig/*_diff.sh header).

Architecture

See the org design DESIGN.md (§3.3, §9 M4, §10). Design + decisions are recorded in the knowledge graph under fixpoint-linux M4 init system design (fx-init).