Three general methods for passing parameters Essay

2.13
Three general methods for passing parameters
Passing parameters in registers.
If the parameters are more than the number of registers, parameters can be stored in block, table or in memory and the address of the parameters can be passed through registers.
Parameters can be passed on the stack by program and can be popped using operating system.
2.17
An user should be able to develop new command interpreter using system calls. The command interpreter allows users to create and manage processes. The communication is done through pipes and files. This functionality can be accessed by user level program using the system calls. Also, the command interpreter is a simple program that forward commands and arguments to the necessary programs or make the necessary system calls directly.
2.18
The two models of interprocess communication are
1. Shared memory model
Strength
When the processes are on the same machine, the memory transfer speed is faster and it is very convenient for communication.
Weakness
In shared memory, the reading and writing of data is done in the shared areas, so the processes are responsible and make sure that they are not writing data to same location simultaneously.
Processes that communicate using shared memory need to fix the problems of memory protection and synchronization.
2. Message passing model
Strength
Easy to implement than shared memory when communicating small amounts of data.
Weakness
The communication in this process is slower since the set up should be made between the systems using the host name of the individual computers.
2.21
The communication in Microkernel approach is, the operating system removes all the nonessential components and implement through system and user level programs i.e. the communication is done between user mode and kernel mode. The type of communication in this approach is message passing.
The client programs and file service never interact directly. The client can interact directly with the file server.
Advantage
Extending operating system in this approach is easy. If there are any new services added, no modification of kernel is required, and the services are added to user space.
The operating system that is extended can be easily ported from one hardware design to other.
Since the services are running as user, the security and reliability is more.
Disadvantage
The performance reduces due to increased systemfunction overhead.
2.23
Similarities between iOS and Android
Both are operating systems for mobile devices.
They both are programmed in c, c++.
The interface for both are touch screen and voice.
The Applications and voice assist are almost similar in both.
Differences between iOS and Android
iOS is a closed source and Android is open source.
iOS is specific only to apple products whereas android is compatible with many platforms.
iOS is not customizable whereas android can be customized.
Even though both are operating systems for mobile devices, iOS base OS is UNIX and OSX whereas android is LINUX.