Applications

Applications

This page inventories executable images and dedicated interactive applications shipped with XAIOS. Standalone programs are started through the kernel loader with explicit capabilities; arbitrary host binaries and FreeBSD/Linux binaries do not execute in XAIOS.

Shell built-in commands such as ls, ssh, and scp are documented separately in Commands.

Boot and service applications

Path	Purpose	Normal startup
/init	First userspace process. Establishes the initial service lifecycle and returns status to the kernel.	Started once during boot.
/bin/service-manager	Exercises and owns the bounded service-manager protocol used for managed workers.	Started during boot.
/bin/xaios-worker	Joinable worker process used for scheduler, CPU-assignment, and service-lifecycle work.	Started by the service manager; count follows the boot profile.
/bin/sshd	Persistent SSH/SFTP server, authenticated PTY transport, outbound SSH/SCP client host, and userspace adapter for the kernel command dispatcher.	Started only after networking and the configured external IPv4/DNS readiness check succeeds.

Administrative applications

Path	Purpose
/bin/xaiosctl	Administrative client for the versioned xaios.control.v1 protocol. It exposes status, health, hardware, metrics, logs, configuration, identity, audit, storage, and ModelFS rendering/authorization paths. The interactive shell exposes a bounded compatibility command family.
/bin/xapt	Signed application and system updater. It refreshes a monotonic architecture-specific catalog, installs or upgrades individual applications without rebooting, and streams an OS image to the inactive A/B slot.
/bin/xaios-shell	Scripted acceptance application for built-in remote-login commands and archives; it is not the persistent interactive shell process. Standalone applications are covered by the SSH gates.

Repository applications

Applications in the signed repository are not built into the boot image. xapt downloads them into a staging area, verifies their manifest and payload, then atomically activates them in /apps.

The current production catalog does not advertise optional applications. New applications will appear in xapt list only after a real application binary and its signed package metadata have been published for the running architecture. Package-manager tests use an explicitly test-only fixture that is never part of the production application catalog.

Interactive terminal applications

These are applications rather than shell built-ins. Each is shipped as a dedicated ELF image. Shared terminal engines are owned under userspace/apps/terminal; the local-console and SSH PTY hosts link those app modules only as transport adapters. No editor, monitor, or game logic is built into the kernel.

Path	Interactive transport	Purpose
/bin/nano	Dedicated ELF plus shared app-owned PTY module	Full-screen editor with cursor movement, insertion/deletion, save, search, and exit. The editing buffer is limited to 32 KiB.
/bin/htop	Dedicated ELF using the typed runtime-snapshot control operation	Full-screen sampled process monitor with color, alternate-screen in-place refresh, runtime-sized CPU meters, sorting, filtering, tree view, keyboard navigation, and a 60 FPS rendering cap.
/bin/pong	Dedicated ELF plus shared app-owned PTY module	60 FPS terminal Pong. W/S control the left paddle, the computer controls the right, and session win/loss counts adjust ball speed by one percent per round.

Diagnostic applications

These executables are not started on a normal boot. An authenticated exact-name remote command can launch an allowlisted diagnostic as a transient process; the kernel reports its exit status and reclaims it. The dedicated XAIOS_BOOT_TEST_APPS=1 image profile may run them during deterministic QEMU acceptance.

Path	Purpose
/bin/hello	Minimal userspace toolchain, ELF loader, logging, and exit integration check.
/bin/helloworldc99	Hosted ISO C99 demonstration built against the XAIOS libc. It prints Hello, World! through stdio and is available on demand as helloworldc99.
/bin/sysinfo	Legacy compatibility diagnostic that directs administrators to xaiosctl status and xaiosctl hardware.
/bin/systest	Syscall, descriptor-width validation, and MutableFS create/read/stat/list/rename/delete suite.
/bin/smptest	SMP scheduler visibility, worker groups, and EL0 thread create/join/validation test.
/bin/nettest	App-callable UDP/TCP, external session, and asynchronous DNS/cache telemetry test.
/bin/lstm-xor	Deterministic CPU-only LSTM/XOR fixture. It also verifies that production model decode fails closed; it is not real-model inference.
/bin/sshtest	Scripted SSH-compatible command, filesystem, archive, process, and error-surface acceptance suite.
/bin/mltest	Deterministic CPU ML dispatcher test for XOR, sum, parity, and fixed-point matrix multiplication fixtures.
/bin/posix-shell	Scripted FreeBSD/POSIX-like shell-subset compatibility suite for redirects, pipelines, filters, and filesystem operations.
/bin/agenttest	Bounded agent protocol dispatch test for ping, source-index, Git status, build, denial, and validation cases.

Two applications exist only in the explicit failure-fixture image and are not shipped in the normal image:

Path	Purpose
/bin/app-fail	Returns status 42 to verify ordinary application-failure reporting and reaping.
/bin/app-crash	Deliberately reads an unmapped user address to verify user-mode fault containment, status 128 reporting, reaping, and continued SSH command service.

Execution boundaries

• Diagnostic names are exact allowlist entries; paths, arguments, and arbitrary executable launch are rejected by the remote application dispatcher.
• Built-in shell parsing and most file/archive command handlers currently run in the kernel remote-login subsystem. Their audited migration candidates are listed in Commands.
• SSH transport and outbound SSH/SCP protocol code run in /bin/sshd, not in the kernel. A fault there cannot corrupt kernel state, but it can stop that SSH service until lifecycle recovery restarts it.
• Standard output from a transient hosted-libc application is bounded and returned to the invoking SSH session as well as written to the serial console.
• Interactive terminal applications have dedicated /bin/* ELF images. SSH and local-console PTY adapters consume app-owned modules for terminal transport; non-interactive command execution is dispatched through the ELF entrypoint. The kernel exposes only generic process, filesystem, console, and paged runtime-snapshot primitives.
• A nonzero transient application reports its exit status and is reaped. A synchronous user-mode fault on AArch64 or x86-64 is converted to exit status 128, returns through the normal transient-process boundary, and leaves the kernel, SSH service, and other applications running. Kernel-mode faults remain fatal by design.
• Normal boot does not pre-run hello, sysinfo, lstm-xor, or the other diagnostics.
• Installed repository applications are loaded on demand with the capabilities declared in their signed manifest. They are never started merely by install.

For command syntax see Commands, for package administration see xapt Package Updates, and for lifecycle verification see Testing XAIOS.