Unix Kernel

2. 
 A kernel is the central part of an operating system.
 In which information is saved about all hardware
component
 It manages the tasks of the computer and
the hardware
 A well-known example of kernel is the Mach kernel
Kernel

3. 
 It can be thought of as the program which controls all
other programs on the computer
 It is responsible for the creation and destruction of
memory space which allows software to run manages the
file system and sets interrupts for the CPU to
enable multitasking.
 Many kernels are also responsible for ensuring that faulty
programs do not interfere with the operation of others
Role Of Kernel

4. 
 There are two types of kernels
 A microkernel, which only contains basic
functionality;
 A monolithic kernel, which contains many drivers.
 A computer user never interacts directly with the
kernel. It runs behind the scenes and cannot be seen,
except for the text logs that it prints.
Types Of Kernel

5. 
 Microkernels are a way of solving this problem
 In a microkernel operating system, the kernel deals only
with critical activities - such as controlling the memory
and CPU - and nothing else
 Minix is a microkernel operating system.
 It deals only with critical activities - such as controlling
the memory and CPU - and nothing else
 It is flexible
Micro kernel

6. 
 Operating systems commonly use monolithic kernels
 Drivers are often implemented as part of a kernel
(specifically Loadable Kernel Modules).
 When a device is needed, its extension is loaded and
'joined' onto the kernel - in other words making the kernel
larger.
 It includes all the necessary functions
Monolithic kernel

7. 
 User Space
 System Call
 Kernel Space
Kernel Architecture

8. 
 The User Space is the space in memory
 Where user processes run.
 This Space is protected.
a) The system prevents one process from
interfering with another process.
b) Only Kernel processes can access a user
process
User Space

9. 
 User Space and Kernel Space are in different spaces.
 When a System Call is executed ,the arguments
to the call are passed from User Space to
Kernel Space.
 A user process becomes a kernel process when it
executes a system call.
System Call

10. 
 The kernel Space is the space in memory
where kernel processes run.
 The user has access to it only through the
system call.
Kernel Space

11. 