Development and Implementation of a File System for Gannet Virtual ...

3.1.2 Non Functional Requirement
As discussed above, Gannet system is embedded system that operates on high
constraint environment. The constrain demands the system to be able have an
interaction and communication with other devices. However, those devices are
issued from different vendors and built on different platform. Hence, the file
system’s interfaces must compliance with range of vendors, platforms and also
architectures. The file system also must be built on the same programming language
as Gannet system which is C/C++.
The final section of the requirement gathering specification for both functional
requirement and non-functional requirement is listed in appendix A. More
discussion regarding the aspect to design the system can be found in a later section.
3.2 File System Design
Having requirement specification, the next step is designing upon a data structure.
Since the file system is developed on C program language, instead of explaining the
class, in this section I explain the design of data structures underneath GannetFS file
system.
GannetFS file system is designed to be implemented on GannetVM platform. It is
designed to be a reconfigurable file system that has standard POSIX file system
interface to its user. As GannetVM does not have secondary storage device, instead
of establishing file system on hard disk, GannetFS is built on Gannet’s RAM memory
region which reserved for this purpose. GannetFS file system is also designed to be
able to operate without depending on system call from kernel since GannetVM
platform does not have kernel or operating system. In Gannet system, all services
are performed by service cores instead of kernel.
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