We will now shift focus to standard application deployment. After power up, the code in Boot ROM is executed. An NVM memory bootloader may be used as a first level bootloader to copy in the internal SRAM a second level bootloader. In this example, the second level bootloader is the AT91 Bootstrap. This application is a bootstrap for SAM9 MPU microcontrollers. It can be uploaded and launched by the ROM Boot Program and can be used to configure the system and to download a larger application. Then, the 2nd level bootloader may (or may not) be used to download a 3rd bootloader such as the u-boot (Linux) or e-boot (Windows CE), which have many more features available for the OS development. Finally, the third level bootloader will call the final application: maybe Linux, WinCE or a stand alone application.