HARDKERNEL ODROID-XU4, Руководство пользователя

Страница: 37 / 92

32
ODROID-XU4 USER MANUAL
If the ODROID-XU4 is being used as part of robotics project, a
lightweight environment such as Blackbox may be more suitable, in
order to free up the amount of memory available for the main controller
application. Other specialized environments are also available from
Synaptic Package Manager, including Ubuntu Studio, which includes
many applications that are primarily used for creating and producing
music, videos, artwork, and photography.
Kernel
At the heart of the Linux system is the kernel, which is respon-
sible for allowing the desktop environment to communicate with the
hardware through a common interface. Each ODROID has its own
customized kernel code that is modified, tested and published by
Hardkernel. Programmers may also download the source code from
the official repository at
http://github.com/hardkernel
and make any
modifications or contributions that they wish.
The Linux kernel is compatible with all versions of Linux, so any
operating system that has been compiled for the ARM hard-float ar-
chitecture (ARMHF) may be converted to run on the ODROID by in-
stalling an ODROID-XU4 kernel and modifying the boot partition. This
makes Linux one of the most versatile operating systems available,
since it can be configured to run on almost any device, including lap-
tops, desktop PCs, smartphones, and ODROID microcomputers.
Graphical User Interface (GUI)
All versions of Linux offer a command line interface (CLI), and
sometimes include a window manager and desktop environment that
is launched on startup. Most modern Linux systems such as Ubuntu
use a library called X11 to create a windowing environment and provide
graphics libraries so that users may interact with applications using a
mouse. The ODROID-XU4 includes a Mali T628 Graphics Processor
Unit (GPU) which is controlled by X11, in conjunction with the Open
Graphics Library (OpenGL), in order to render graphics on a 720p or
1080p monitor. ODROIDs use a subset of the popular OpenGL library
called OpenGL ES, which is specifically designed to work with ARM
processors, especially smartphones. Applications that are written for
OpenGL ES can use low-level graphics functions on the GPU chip
itself in order to quickly and efficiently render graphics, resulting in a
much faster and smoother user experience than using the CPU alone.
720p vs 1080p
ODROIDs support both 720p and 1080p monitor configurations,
which are video resolutions commonly supported on LCD TV’s and on
many LCD computer monitors. 720p is sometimes referred to as HD,
Chapter 3