src/sys/bootstrap/meta/ptysvc.cml

{
    program: {
        binary: "bin/ptysvc",
    },
    use: [
        { runner: "elf" },
        { protocol: "/svc/fuchsia.boot.WriteOnlyLog" },
    ],
    expose: [
        {
            protocol: "/svc/fuchsia.hardware.pty.Device",
            from: "self",
        },
    ],
}