1.3 Terminology
Terms defined where they are introduced — activation generation, boot generation, transition cause, cgroup generation, start generation — are not repeated here.
Service. A named, supervised unit of execution: a definition in the registry, a runtime state, a Security Descriptor, and at most one running main process. Services are the primary unit of management and the thing dependencies are expressed between.
Job. One supervised process execution. Every fork peinit performs is a job — a service's main binary, a pre-exec hook, a health check invocation, an ad-hoc submission — with a GUID, a lifecycle, a token summary and a log correlation key. Jobs are the observable unit of what actually ran.
Operation. A first-class object representing a requested state machine action on a service. Control commands do not mutate state directly; they create operations that are validated, queued, resolved against whatever else is in flight, and executed by the event loop.
Trigger. A rule in a service definition saying when the service starts automatically: at boot, once the boot set has settled, or on a schedule. A service with no triggers starts only when something asks for it.
Phase 1. The compiled-in bootstrap: root writability, the remaining virtual filesystems, the persisted random seed, the local machine ID, the clock, registryd, boot-time path provisioning, and infrastructure setup. No registry access happens before registryd is serving.
Phase 2. The registry-driven boot: read the service definitions, build and validate the dependency graph, and start the boot-triggered services in dependency order.
ErrorControl. The per-service policy for an irrecoverable failure. Normal leaves the service Failed; Critical syncs the filesystems and reboots.
Token. The per-thread KACS identity object — a user SID, group SIDs, a privilege bitmask, an integrity level, and metadata. Tokens are the sole identity mechanism: peinit sets no UIDs, GIDs, or Linux capabilities on service processes. Peios Kernel TRM §3.2.
Security Descriptor (SD). The KACS structure controlling access to a securable object. peinit uses two: a ServiceSecurity descriptor per service, controlling who may manage it, and its own control descriptor, controlling system-level operations. Peios Kernel TRM §3 and PCDS §5.
AccessCheck. The KACS function that evaluates a token against a descriptor to produce a decision. peinit calls it for every control request. Peios Kernel TRM §3.8.
Per-service SID. A SID under authority S-1-5-80 derived
deterministically from the service name, carried in the group list of
every service token. Two services running as the same principal are
still distinguishable to an access check. §4.4.
registryd. The userspace registry source daemon serving the persistent hives. peinit starts it in Phase 1 from a compiled-in definition and treats it as opaque thereafter. Its implementation is loregd, a distinction visible only in recovery mode.
Registry. The configuration system LCS and its sources provide
together. peinit reads service definitions from
Machine\System\Services\, boot configuration from
Machine\System\Boot\, and its own parameters from
Machine\System\Init\.
KMES. The kernel-mediated event subsystem. peinit emits its structured events — job and operation lifecycle, audit records — into its ring buffer, where they survive eventd restarts and reboots. Peios Kernel TRM §2.
JFS. The Job Forwarding Subsystem: the kernel bridge that captures a
caller's effective token and delivers it, with a job definition, to
whatever holds /dev/jfs open. peinit is the consumer. §8.5.
pidfd. A descriptor referring to one specific process, obtained
atomically at fork through clone3(CLONE_PIDFD). Every process peinit
supervises is tracked by one, which is what makes supervision immune to
PID reuse.
cgroup. peinit uses cgroups v2 for process tracking and clean kill
only — not for resource accounting or limits. Every service gets its own
tree under /sys/fs/cgroup/peinit/. §5.1.
sd_notify. The datagram protocol services use to report readiness,
status, keepalives and stored descriptors, over the socket named by
NOTIFY_SOCKET. Specified in PSPU §4.
TCB. The Trusted Computing Base: the kernel, KACS, LCS, KMES, peinit, registryd, authd, lpsd and eventd. A compromise of any of them compromises the system.