Operating System Final Revision Part 2 2025

Operating System Final Revision (Part 2) 2025

• Component of Computer System Structure: Hardware, Operating System, Application Programs. All of the above.
• Bootstrap Program: Not loaded at the power-up or reboot. It does load the operating system kernel. It is stored in read-only memory (ROM).
• Process Management Activities: Process management activities include creating, deleting, and handling user processes; communication between processes; process synchronization; and deadlock handling. Creating and deleting user processes or providing mechanisms for process communication are not activities of process management.
• Deadlock: A situation in which every process in a set of processes is waiting for an event that can be caused only by another process in that set.
• Context Switching: Information in use copied from slower to faster storage temporarily. A type of computing that delivers computing, storage, and even applications as a service across a network.
• Cloud Computing: A type of computing that delivers computing, storage, and even applications as a service across a network.
• Virtualization: Allows operating systems to run as applications within other operating systems.
• DMA (Direct Memory Access): Data Memory Access. Direct Memory Access.
• Multiprocessor Systems Advantage: Economy of scale, increased throughput, and increased reliability.
• Arduino Platform: The standard Arduino platform does not provide an operating system. A small piece of software, a "boot loader" or "booter" or "sketch", is used instead.
• Linker: Combines relocatable object files into a single binary executable file.
• Loader: Brings the program into memory to be executed.
• Monolithic Operating System Structure: All kernel functionality in a single, static binary file within a single address space.
• Microkernels Operating System Structure: Removing nonessential components from the kernel; implementing them as user-level programs in separate address spaces.
• Disadvantage of Microkernels Structure: Difficult to extend, difficult to port, and the overhead of user space to kernel space communication.
• Context Switching: The system must save the state of the old process in its PCB and load the saved state for the new process, using context switching.
• Interrupt: When an interrupt occurs while a process is executing in the CPU, it moves to the Waiting state. Resource allocation, protection and security, and communications are operating system services.
• Linux Parameter Passing: Parameters can be passed to the operating system using registers, stack.
• UNIX Process Creation: The fork() system call is used to create a new process in UNIX.
• Memory Sections: The sections of memory that contain dynamically allocated memory during program run time are called the text section, stack section, data section, and heap section.
• Communication Types: Synchronous communication, asynchronous communication, direct communication, indirect communication.
• Deadlock Conditions: Mutual exclusion, hold and wait, no preemption, and circular wait.
• Banker's Algorithm: Used for deadlock avoidance with multiple instances of resources. Each process must claim the maximum use of each resource type in advance.
• Address Binding Time: Compile time, load time , and execution
• Logical Addresses: Virtual addresses.
• Physical Addresses: Memory addresses seen by the memory unit.
• Memory Management Unit (MMU): A hardware device that maps logical addresses to physical addresses.
• Page Table: Contains the base address of each page in physical memory, using the page number as an index.
• Page Number: An index into the page table.
• Page Offset: Used with the base address to define the physical memory address.
• Protection Bit: Associated with each frame to control read/write access.
• Swapping: A technique to transfer pages between memory and the backing store when physical memory is oversubscribed.
• Overhead: The execution time of memory management operations.
• Dynamic Relocation: The process of adding the value in the relocation register to every address generated by a user process at the time the address is sent to memory.
• Techniques to reduce External Fragmentation: Compaction.
• Memory Protection Bit: Read-only or read-write access is allowed, and a bit is used to indicate whether an associated page is in the process's logical address space.
• Paging Advantages: Reduces external fragmentation.
• Internal Fragmentation: Fragmentation that causes wasted space within a memory partition.
• Memory-Management Unit (MMU): Maps logical addresses to physical addresses.