CGS 3763 Operating Systems Concepts Spring 2013 Dan C. Marinescu Office: HEC 304 Office hours: M-Wd 11:30 - 12:30 AM

Lecture 6 – Friday, January 18, 2013 Last time: Abstractions; interpreter, storage, communication channel Memory hierarchies. Protection – user and kernel mode execution Priviledged/non-privileged instructions Today: Kernel functions System calls The structure of a UNIX kernel Examples of operating systems Week in review – problems from chapter 2 Next time Process; process state; a process in memory Kernel data structures for process management 12/6/2018

Assignments Chapter 3 of the text book Reading assignments: Chapter 3 of the text book The computer architecture material HW1 due Wednesday 12/6/2018

Kernel functions Program execution: Input/Output operations: Process management Scheduling and resource allocation Interrupt handling: Error handling Input/Output operations: Storage management - file system manipulation: Security enforcement Accounting 12/6/2018

System calls Process control File management Device management Load Execute Create, terminate a process Block a process, abort Get process attributes/set process attributes Allocate/deallocate memory for a process File management Create/Delete file Open/Close file Read/Write file Get/Set file attributes Device management Information maintenace 12/6/2018

System calls (cont’d) Communication File management Device management Create/Delete file Open/Close file Read/Write file Get/Set file attributes Device management Request/Release device Read from/Write to device Get/Set device attributes Information maintenance Get/Set time/date Get/Set attributes Communication Create/Delete communication connection Send/Receive message 12/6/2018

Unix kernel 12/6/2018

Examples of operating systems Multix – developed at MIT in mid 60s Unix – develop at ATT by  Ken Thompson, Dennis Ritchie,  Brian Kernighan, Douglas McIlroy, Michael Lesk, and Joe Ossanna in 1969. BSD-Unix developed at U. C. Berkeley 1977. Mach – developed at Carnegie-Mellon in mid 1980s. It is a microkernel. MAC OS X 12/6/2018

MAC OS-X 12/6/2018