問2
頻出度★☆☆
PC用のOSを情報家電のOSに採用することがある。その目的として,最も適切なものはどれか。
平成26年度 春期 ITパスポート試験 問2
テクノロジ系ソフトウェア › オペレーティングシステム
This question's explanation and your answers so far.
解説
問 2
Incorrectア
Incorrect. A PC OS covers a wide range of uses, so it has many functions and is large in scale, and the memory needed to run it actually increases. If you want to cut memory, it is more appropriate to adopt a dedicated embedded OS (such as a real-time OS) that includes only the necessary functions; reusing a PC OS produces the opposite result from this purpose.
Incorrectイ
Incorrect. Because PC operating systems are used widely around the world, information about their known vulnerabilities, the attack techniques against them, and viruses is also widely circulated. If the same OS is adopted in an information appliance, attack techniques that exist for PCs tend to work on it as they are, so the risk of becoming a target of external attacks actually rises. The risk goes up rather than down, so this cannot be the purpose.
Incorrectウ
Incorrect. A PC OS is designed with general-purpose use as the priority; it is not optimized for the limited hardware resources of a device, and it is not suited to real-time control where the response time must be guaranteed. If you are pursuing processing speed, an OS or software built specifically for the device is more advantageous, so adopting a PC OS cannot be said to bring higher processing speed.
- エ
正解 The correct answer is エ (Shortening the software development period). Software embedded in an information appliance (a TV, a recorder, a car navigation system, and so on) would normally require building a device-specific embedded OS from scratch, together with the control programs that run on top of it. If a proven PC OS (such as Windows or Linux) is adopted as it is, there is no need to develop the OS itself, and the existing development tools (compilers, debuggers, integrated development environments), the rich libraries and middleware, the standardized APIs, and the skills of engineers experienced in PC development can all be reused directly. Functions such as network communication and GUIs are also provided by the OS from the start, so the range that must be implemented in-house is greatly reduced. As a result, the man-hours needed for design, implementation, and testing go down, which shortens the development period and brings the product to market sooner. In other words, the aim of reusing a PC OS lies not in improving performance but in development productivity, and that is the key point of this question.
ここがポイント
- The aim of adopting a general-purpose OS (a PC OS) in an embedded system is to reuse existing development environments, libraries, APIs, and engineers' skills, thereby cutting development man-hours, shortening the development period, and bringing the product to market sooner. It is not done for performance or for saving resources.
- The trade-off between a general-purpose OS and an embedded OS: a general-purpose OS is rich in functions and easy to develop on, but it needs more memory, is weaker in real-time performance, and carries a greater security risk of being attacked through known vulnerabilities. A dedicated embedded OS is the opposite: economical with resources and strong in real-time performance, but heavier in development burden.
用語