Module 1: Introduction Flashcards
Describe the difference between abstraction and virtualization.
Abstraction is the act of removing unimportant details or attributes of objects in order to construct more general and less complex objects. Virtualization is the illusion of having one or more objects with more desirable characteristics than the real object.
Describe the Kernel
The kernel is the minimum set of functions necessary to manage system resources safely and efficiently.
Describe Privileged Instructions
Privileged instructions perform critical operations that access I/O devices and the CPU’s status and control registers.
Describe Kernel Mode
Kernel mode is the CPU state where both privileged and non-privileged instructions may be used.
Describe User Mode
User mode is the CPU state where only non-privileged instructions may be used. Any attempt to use a privileged instruction in user mode transfers control to the kernel.
Describe Interrupts
An interrupt is an event that diverts the current execution of a program to a predefined location in the kernel in order to respond to an event. An interrupt is triggered by a hardware signal sent to the CPU from an external device.
Describe Traps
A trap (or internal interrupt) is an interrupt triggered by the currently executing instruction.
Describe Interrupt Handlers
An interrupt handler is a kernel function, invoked whenever an interrupt occurs, that determines the cause of the interrupt and invokes the appropriate kernel function to provide the response.
Describe Moore’s Law
Moore’s Law states that the number of transistors in an integrated circuit doubles about every two years.
Name the different types of operating environments.
Mainframe, server, multiprocessor, distributed system, personal computer, hand-held device, real-time (embedded) system, sensor network
