1. System Calls
1.1. provide the interface between a running program and the operating system
1.2. general methods are used to pass parameters
1.2.1. Pass the parameters in registers.
1.2.2. Parameters stored in a block, or table, in memory, and address of block passed as a parameter in a register.
1.2.3. Parameters placed, or pushed, onto the stack by the program and popped off the stack by the operating system.
1.3. Types of System Calls
1.3.1. Process control
1.3.2. File management
1.3.3. Device management
1.3.4. Information maintenance
1.3.5. Communications
1.3.6. Protection
2. Microkernel
2.1. Small operating system core
2.2. Contains only essential core operating systems functions
2.3. Benefits
2.3.1. Extensibility
2.3.2. Flexibility
2.3.3. Reliability
2.3.4. Portability
3. Operating System Design
3.1. Design and Implementation of OS not “solvable”, but some approaches have proven successful
3.2. Start by defining goals and specifications
3.2.1. goals
3.2.1.1. User goals
3.2.1.2. System goals
3.2.2. specification
3.2.2.1. type of system
3.2.2.2. choice of hardware
4. Operating System Services
4.1. User interface
4.2. Program execution
4.3. I/O operations
4.4. File-system manipulation
4.5. Communications
4.5.1. message passing
4.5.2. shared memory
4.6. Error detection
4.7. Additional Operating System Functions
4.7.1. Resource allocation
4.7.2. Accounting
4.7.3. Protection and security
5. Layered Approach
5.1. In layered approach, the operating system is divided into a number of layers (levels), each built on top of lower layers. The bottom layer (layer 0), is the hardware; the highest (layer N) is the user interface.
5.2. Advantage
5.2.1. Simplicity of construction and debugging
5.3. Disadvantages
5.3.1. The careful definition and interaction of the layers
5.3.2. Less efficient