sdk/fidl/fuchsia.driver.host/driver_host.fidl

// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.driver.host;

using fuchsia.driver.framework;
using fuchsia.ldsvc;
using zx;

/// Protocol through which a driver's lifecycle can be managed.
///
/// The Driver Runner will call Stop() on this protocol to indicate that the
/// Driver Host should stop the Driver. The Driver Host should close the
/// server end of the channel with an epitath to signal that the driver has
/// been stopped.
///
/// EPITAPH
///
/// This protocol sends a FIDL epitaph to indicate that the driver instance
/// has been terminated correctly. The Driver Host must send an epitaph of
/// ZX_OK in order to indicate the Driver was Stopped correctly.
/// Not sending an epitaph, or sending an error, will cause Driver Runner
/// to log an error.
closed protocol Driver {

    /// Request that the Driver is Stopped.
    ///
    /// After stopping the driver instance, the server should close this
    /// connection with an epitath. This signals that the Driver has been
    /// stopped.
    strict Stop();
};

/// Information about the driver host. Used for debugging.
type ProcessInfo = struct {
    job_koid uint64;
    process_koid uint64;
};

/// Protocol through which a driver host can be managed.
@discoverable
closed protocol DriverHost {
    /// Start a driver within a driver host.
    strict Start(resource struct {
        start_args fuchsia.driver.framework.DriverStartArgs;
        driver server_end:Driver;
    }) -> () error zx.Status;

    /// Returns the job and process KOIDs of the driver host.
    strict GetProcessInfo() -> (ProcessInfo) error zx.Status;

    /// Provides a loader service which should be installed via
    /// `dl_set_loader_service`.
    strict InstallLoader(resource struct {
        loader client_end:fuchsia.ldsvc.Loader;
    });
};