seriald

seriald is the serial console mediation service in EriX userspace.

EriX is a clean-room, capability-based microkernel operating system written entirely in Rust.

Technical requirements are tracked in the EriX requirements, conventions, and project documentation.

See:

• docs for design documents, specifications, and development plans.
• Related architecture repositories for kernel, services, libraries, drivers, and integration tooling.

Purpose of This Repository

This repository implements the EriX serial service daemon. Its purpose in EriX is to provide the serial service role through explicit IPC and startup authority.

Functionally, it implements the daemon runtime, state model, IPC handling, and validation tests. The repository keeps the implementation, interface contracts, tests, and documentation for that behavior in one reviewable ownership boundary.

The maintained responsibilities are:

• implement the serial service runtime and state model
• validate startup authority before accepting IPC requests
• handle bounded service operations through the assigned endpoint set
• keep service behavior, tests, and authority invariants documented

Clean-Room Policy

EriX follows a strict clean-room philosophy:

• No external source code may be copied.
• No external Rust crates are allowed.
• No code generation tools that embed third-party code.
• All code must be authored within the project.

Violations will result in rejection of the contribution.

License

All EriX repositories are licensed under the ISC License.

Development Model

EriX development is modular, deterministic, reproducible, authority-explicit, security-first, and self-hosting oriented.

This repository follows the project roadmap and the validation rules documented in its own roadmap.

Runtime model

• Single-threaded service loop.
• Fixed message buffers (IPC_MSG_BUFFER_BYTES = 1024).
• Fixed stream ring (STREAM_RING_CAPACITY = 4096).
• Peer-only runtime authority: provider, named, and deviced endpoints only.
• Startup keeps seriald on the explicit peer path: deviced is required for HAL/provider flow, while named publication is attempted only when a real delegated named send cap is present.
• Background deviced registration is primed once after the startup reply and then retried from the single-threaded service loop's idle/provider path.
• Idle provider probes use a shorter timeout budget than the underlying transport call, keeping the recv loop responsive while still warming the provider binding ahead of phase3 verification. Foreground writes now share the same short-budget provider refresh, so the write path fails fast with RETRY instead of spinning through a long resolve burst.
• No dynamic allocation and no external crates.

Feature flags

• seriald-integration-smoke
• seriald-integration-force-fail
• seriald-integration-phase3-serial

Default build has no integration feature enabled.

Build and test

cargo fmt --all -- --check
cargo clippy --all-targets --all-features -- -D warnings
cargo test --all-targets --all-features

Repository CI additionally runs default-feature cargo build, cargo test, and cargo doc with branch-aware dependency overrides.

Dependencies

• lib-bootstrap
• lib-capabi
• lib-ipc
• lib-service
• ipc-syscall-x86_64

No third-party crates are used.

Governance Principles

seriald governance is scoped to serial console service behavior above serial drivers.

The scoped governance rules are:

• It consumes only explicit serial-provider authority.
• It keeps console input/output bounded by the service IPC contract.
• It separates serial service policy from hardware driver ownership.
• It does not manage serial hardware directly or start drivers.

Authority Boundaries

• seriald operates only through startup-assigned service capabilities.
• New authority must be represented in bootstrap/capability validation and integration tests before use.

Contact

Development occurs in EriX organization and discussions happen in issues and design documents.

No decisions are considered valid without documented rationale.

Maintainers can be reached via email: admin@erikinkinen.fi.