Kernel stage can also be broken in few stages. But the preliminary stage is BSP-Board Support Packages, which is the code specific to hardware/chip. BSP is responsible for the assigning of the various functionality operations to the controllers and pins of the chip. After this, operations such as initialization of interrupt controllers, setting up of memory protections, caches and scheduling, memory management occur.
Generally speaking filesystem is way of organizing data. This is very basic definition, but the tasks performed by filesystem are itself very vast. This stage is loaded by the bootloader and is called in the middle of the Kernel stage. All the data present in the mobile or any system is organized, stored and updated because of filesystem. In case of embedded system generally used filesystem are YAFFS, UBIFS, UFFS etc
· System Startup
As the kernel and filesystem are up, then the system startup process can began. From this stage all the processes that occur are related directly with the user space applications. From the libraries to the framework, all the work takes place in this layer. Web manager, Sound manager, Graphics manager etc. all are brought to life in this phase. At the end of this phase applications are launched.
This is the final and apparent stage, which is seen by everyone. This leads to the display of the user defined settings and the applications launching. GUI is graphic user interface that is a way of communicating with the mobile by its user.
This is how a small but a complex machine comes to life.
Filed Under: How to