sdk/fidl/fuchsia.boot/arguments.fidl

// Copyright 2020 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.boot;

const uint8 MAX_ARGS_NAME_LENGTH = 64;
const uint8 MAX_ARGS_VALUE_LENGTH = 128;
// MAX_ARGS_NAME_LENGTH + MAX_ARGS_VALUE_LENGTH + 1 (for '=')
const uint8 MAX_ARGS_COLLECT_LENGTH = 193;
const uint8 MAX_ARGS_VECTOR_LENGTH = 32;

struct BoolPair {
    string:MAX_ARGS_NAME_LENGTH key;
    bool defaultval;
};

/// Protocol for retrieving boot arguments.
[Discoverable]
protocol Arguments {
    /// Get the value of a boot argument `key`.
    GetString(string:MAX_ARGS_NAME_LENGTH key) -> (string:MAX_ARGS_VALUE_LENGTH? value);

    /// Get the values of a list of arguments specified in `keys`.
    GetStrings(vector<string:MAX_ARGS_NAME_LENGTH>:MAX_ARGS_VECTOR_LENGTH keys) -> (vector<string:MAX_ARGS_VALUE_LENGTH?>:MAX_ARGS_COLLECT_LENGTH values);

    /// Get the boolean value of a boot argument `keys`,
    /// or return `defaultval` if the argument is not present.
    /// A key is considered to be false if its string value is exactly
    /// "off", "0", or "false". Any other value (including empty) is returned
    /// as true.
    GetBool(string:MAX_ARGS_NAME_LENGTH key, bool defaultval) -> (bool value);

    /// Get the boolean values of a list of boot arguments `keys.key`,
    /// or return `keys.defaultval` for each if not present.
    GetBools(vector<BoolPair>:MAX_ARGS_VECTOR_LENGTH keys) -> (vector<bool>:MAX_ARGS_VECTOR_LENGTH values);

    /// Get all boot arguments with keys starting with
    /// `prefix`. Returns a vector with strings of the form 'key=value'.
    /// TODO(fxbug.dev/33460) - remove Collect once boot arguments have been componentised.
    Collect(string:MAX_ARGS_NAME_LENGTH prefix) -> (vector<string:MAX_ARGS_COLLECT_LENGTH>:MAX_ARGS_VECTOR_LENGTH results);
};