A cross compiler is fundamentally used to separate the build environment from the target environment, which is very useful for embedded systems. Within embedded systems devices often have extremely limited recourses.
In this case Yocto is going to be used as development environment. Which also contains a cross compiler, because Yocto needs a lot of processing power and memory.
This means that it is not possible to run Yocto from an embedded system. Therefore this cross compiler is needed to be able to compile the Linux kernel, kernel drivers and eventually software applications.
First this chapter will give a brief introduction to the Yocto Project, after this introduction it contains information about how to configure Yocto to build an architecture specific cross compiler for an ARM Cortex-M3.
2.1 Introducing the Yocto Project
The Yocto Project is a complete embedded Linux development environment. That provides templates, tools and methods to help creating custom Linux-based systems for embedded products regardless of the hardware architecture.
This paragraph contains information about the basic Yocto fundamentals.
2.1.1 Yocto layers
Yocto uses layers to add customizations. A layer is a logical collection of recipes representing the kernel, a Board Support Package (BSP) or an application. All layers have a priority and are able to override the policy and configuration settings of the layers beneath it.
Figure 2 1 gives a graphical representation of the Yocto layer priorities. The lower OpenEmbedded and Yocto layers have the lowest priority and are able to be overruled by the higher level BSP and developer layers.
2.1.2 Yocto hardware configuration
In order to add a machine configuration to a Yocto layer, you need to add several...
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...rce and to start using Yocto in combination with an external binary tool chain.
2.2.3 External tool chain
The external binary tool chain could be retrieved from Mentor Embedded, and since Mentor Embedded does already have a Yocto layer to support their binary tool chains. The external tool chain could be implemented very easily.
Unfortunately the Mentor Embedded Yocto layer gives an example for a GNU Linux external tool chain, instead of an uCLinux external tool chain. And where Yocto normally builds dynamic libraries, the external tool chain with uCLinux for MMU less processor support, does not support dynamic libraries, and is only able to use static libraries.
To change the dynamically build packages to build static libraries, the Yocto variable ‘EXTRA_OECONF’ could be used to set configuration and build variables such as ‘--disable-shared’ and ‘--enable-static’.
Open source software development is taking place all over the world where part of the community develops individual modules, becoming necessary to establish standards and common definitions for open source software. These standards are established to define interaction between modules to insure interoperability of software. Software components which follow specific open standards can be replaced with other standard-compliant product, which allows the user more freedom to choose the component best suited to his needs and is not bound to a particular product, as with commercial software (Chauhan)
...t is undeniably embracing open source more and more, ... Microsoft Building Hybrid Open Source Software Development Model ... Jun 11, 2008 ...
“a global leader in unified communications (UC) solutions with industry-leading telepresence, video, voice and Polycom UC Intelligent Core™ infrastructure solutions—all built on open standards. Polycom's vision and strategy is to enable UC Everywhere—allowing people to communicate and collaborate anywhere on multiple devices” (Polycom Corporate, 2011).
Keywords Xinu INTRODUCTION In recent years, several colleges and universities have adopted Embedded Xinu, a modest OS developed in 1984 at Purdue University. Using Embedded Xinu provides a homogeneous form of teaching at a low cost to implement. Due to its simple design, Xinu is ideal for courses on operating systems, embedded devices, networking, and compilers.
Yo-Good is one of four franchise options offered by ‘Fresh & Healthy Brands, LLC”, a corporation based in Burnaby, British Columbia (Serving Up Healthy Choices in New Franchise Opportunities, 2011). The company’s mission is to “offer a delicious and healthy combination of non-fat frozen yogurt with a dazzling variety of fresh toppings” (Yo-Good: Frozen Yogurt with an Important Difference, 2011) in an all-natural way without the use of artificial sweeteners. Our goal is to bring a Yo-Good franchise to the city of Halifax; a city that we believe is in dire need of great tasting healthy alternatives.
The application layer is the OSI layer closest to the user. It differs from the other layers because it does not provide services to any other OSI layer, but rather to application processes lying outside the scope of the OSI model. Examples include spreadsheet programs, word-processing programs, banking terminal programs, etc. The application layer identifies and establishes the availability of intended communication partners, synchronizes cooperating applications, and establishes agreement on procedures for error recovery and control of data integrity. Also, the application layer determines whether sufficient resources for the intended communication exist.
The bottom layer would follow the guideline so they can achieve the company objectives. The group structure is Chairman Board of Directors Group of Executives Board of Management Group of General Management The main departments within the group are: Administration Division Business Division Customer Support Division Network Development Division Production Services Division R&D Department Finance Department Human Resources Each division has managers for supervision. The staff in each division needs to follow the managersÂ’ decision. Every member of staff clearly understands their role and responsibility under the hierarchical structure. It is because each layer gets different responsibilities.
Component Based Architecture creates a system that is easily extensible, promotes software reuse and intuitively understandable. A component often relates to an object in Object Orientated Programming. The RUP provides a systematic way to build this kind of system, focusing on producing an early executable architecture before committing full resources on a project.
Mac OS X is a powerful development platform; it supports multiple development technologies like UNIX, Java, Cocoa and Carbon. It also is host to many open source, web, scripting, database and development technologies. It was build around the integrated stack of graphics and media technologies such as QuickTime, Quartz, Core Image and Core Audio. Mac OS X is based on the Mach Kernel and the BSD implementation of UNIX which were originally incorporated into the NEXTSTEP operating system. Many aspects of the Mac OS X architecture are derived from OPENSTEP / NEXTSTEP which was designed to be an easy transition from one platform to another. At the core of this system is Darwin, an open source UNIX like operating system built around the XNU kernel with standard UNIX facilities available from a command line interface.
OMPARE AND CONTRAST REDUCED INSTRUCTION SET COMPUTER (RISC) WITH THE COMPLEX INSTRUCTION SET COMPUTER (CISC) [20]
Most computer languages use different versions of compilers for different types of computers or operating systems; so one language may have different compilers for personal computers (PC) and Apple Macintosh computers. Many different manufacturers often produce versions of the same programming language, so compilers for a language may vary between manufacturers.
Mono programming is not really of any benefit to us now days. We need to be able to run multiple processes on our machines and one technique of making this happen was by the fixed partitions method. In this method memory is divided into fixed partitions and different jobs/processes are placed on a queue.
The ability of a reference architecture to provide guidance so that future developers understand how to program future applications in a domain is a primary motivation for the generation of a reference architecture. The guidance provided by a reference architecture can reduce development costs.
The final or resulting functionalities can be delivered with ease since the code is being developed with smaller fragments and thoroughly tested. So the resulting implementation does not tend to be complex. [1]
Surran, M. (2003). Making the Switch to Open Source Software. T.H.E. Journal Online. Retrieved September 16, 2003 from T.H.E. Journal Online website: