سوال ۹۶ کنکور ارشد مهندسی کامپیوتر ۱۴۰۵
هدف اصلی یک راهانداز دستگاه (Device Driver) چیست؟
پاسخ صحیح: گزینهٔ B — ارائه API مناسب برای ارتباط با سختافزار
A device driver is the kernel-level software module that lets the operating system talk to one specific class of hardware (a disk, NIC, GPU, keyboard, etc.). Its defining job is abstraction: it exposes a standard, uniform interface (API) — the generic I/O operations such as open/read/write/close/ioctl — and internally translates those calls into the device's own low-level register accesses and commands. Upper layers (the kernel I/O subsystem, applications) can then use the device through this clean API without knowing its hardware specifics.
That is exactly option 2: providing a suitable API for communication with hardware.
Why the other choices are wrong:
| Option | Whose job it really is |
|---|---|
| (1) Link hardware to system-level services | Describes the kernel's I/O subsystem / general OS mediation, not the driver's defining contribution — the driver's specific value is the interface it exposes. |
| (3) Manage physical & logical resources | The classic definition of the operating system / kernel as a whole (resource manager), not of a single driver. |
| (4) Hardware virtualization | The role of a hypervisor / VMM, which multiplexes real hardware into virtual machines. |
Exam trick: Match each phrase to its owner — driver = expose an API / abstract one device, OS kernel = manage all resources, hypervisor = virtualize hardware. The word "API/interface for hardware" is the fingerprint of a device driver.