Operating-System Structure & Services

Practice questions covering operating system services, system calls, structures, and specific mobile OS architectures based on the Silberschatz, Galvin and Gagne 10th Edition materials.

What are the three main types of user interfaces (UI) found in operating systems?

Command-Line (CLI), Graphics User Interface (GUI), and Touch-screen.

What is the purpose of the 'Program execution' operating system service?

The system must be able to load a program into memory and to run that program, ending execution either normally or abnormally.

In the context of OS communications, what are the two primary methods for processes to exchange information?

Shared memory or message passing (where packets are moved by the OS).

What are the three types of OS functions categorized under 'efficient operation of the system itself'?

Resource allocation, Logging, and Protection and security.

What is the primary function of the Command Line Interpreter (CLI)?

It fetches a command from the user and executes it.

Which company invented the GUI (Graphics User Interface) desktop metaphor?

Xerox PARC.

What does the POSIX API stand for in the context of system calls?

An API used for POSIX-based systems, which includes virtually all versions of UNIX, Linux, and Mac OS X.

Briefly describe the three general methods used to pass parameters to the Operating System.

1. Pass parameters in registers. 2. Store parameters in a block or table in memory and pass the address in a register. 3. Push parameters onto a stack to be popped off by the OS.

What are the six categories of system calls?

Process control, File management, Device management, Information maintenance, Communications, and Protection.

Why is the Arduino described as a 'single-tasking' system in the notes?

It has no operating system, a single memory space, and the shell is reloaded only after a program exits.

What are 'daemons' in the context of system services?

Background services that run from system boot to shutdown in user context rather than kernel context.

What is an Application Binary Interface (ABI)?

The architecture equivalent of an API that defines how binary code components interface for a given OS on a specific architecture and CPU.

How is the kernel defined in the monolithic structure of the original UNIX?

It consists of everything below the system-call interface and above the physical hardware.

What is the primary benefit and the primary detriment of a Microkernel structure?

The benefit is easier portability and increased security/reliability; the detriment is the performance overhead of user space to kernel space communication.

How do Loadable Kernel Modules (LKMs) differ from a traditional layered approach?

They use an object-oriented approach where each core component is separate and loadable as needed within the kernel, making them more flexible than layers.

What are the components of the hybrid Darwin kernel used in macOS?

It consists of the Mach microkernel, BSD Unix parts, an I/O kit, and dynamically loadable modules (kernel extensions).

Compare Dalvik and ART (Android RunTime) regarding application compilation.

Dalvik uses runtime conversion of dex files (which can cause unresponsiveness), while ART uses Ahead-of-Time (AOT) compilation during installation to improve speed and battery life.

What is the 'Binder' mechanism in the Android operating system?

A mechanism that enables an object-oriented OS to run on top of a general-purpose OS (Linux) by allowing system services in user-space to extend functionality via new system calls.