18. A processor is generally put into kernel mode through the execution of a trap instruction I wil accept F too, since interrupts also put the processor kernel mode. 19. The purpose of an operating...

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Extracted text: 18. A processor is generally put into kernel mode through the execution of a trap instruction I wil accept F too, since interrupts also put the processor kernel mode. 19. The purpose of an operating system is to manage system resources and to provide a more convenient abstract machine for programming. 20. The main difference between the use of test & set and the use of semaphores is that semaphores require the OS to do the busy waiting rather than the user program.