As open-source Linux operating system are all aspects of IT industry to play a role, Linux is the server’s key operating system.Linux is a key component of embedded systems, it has been embedded in the telecommunications switching equipment, routers, access equipment, network storage devices and mobile terminals, covering all aspects of communications networks. IT industry is very familiar with SUSE, RedHat, Red Flag Linux operating system, as well as in the desktop system, free use of Fedora, Debian, and less understanding of embedded Linux, this is because the embedded device is based on an overall pattern displayed in the use of in front, so the operating system while it is very important component, but it is not easy to let the public know, such as our daily see MP4, GPS, mobile phones and other electronic consumer products, in fact, they are all inside an operating system running on the inside Those in the industry known as the RTOS (real-time multi-tasking operating system) or EOS (the embedded operating system). Just as server and desktop systems, embedded system designer can select a commercial embedded Linux software or to use its own open-source Linux software development, can be entrusted to third-party developers. Commercial Linux software, and in RedHat is a par Montavista software company.
Montavista Linux already has more than 2000 multiple users and tens of millions of products on the market, they are covered from the smart phones, high-definition television, robotics, wireless networking equipment to a variety of 3G telecom server embedded applications.Motorola uses Montavista Linux smart phone ‘out’ in China makes great success with its Linux products Montavista famous domestic.
Montavista Linux History
In 1999 in Silicon Valley-Sunnyvale town inside the addition of an ordinary office, a group of very young entrepreneurs, this is Montavista Founder-Jim Ready, and his entrepreneurial team. About 15 years ago, Jim is in the same place to begin his first embedded operating system company’s entrepreneurial career.Jim founded Ready system’s VRTX is the world’s first commercial RTOS, a wide range of applications in communications, control, and aerospace systems, is a sign of an embedded operating system, and creative products, VRTX ideas for the industry by those who follow the subsequent and development. After several years of observation and reflection, Jim recognized that Linux can support more extensive and updated hardware, additional I / O devices, more and more standard applications, it may be the next embedded operating system, after the most suitable choice , decided to set up a professional embedded Linux company, the company’s positioning is a 100% Linux company, it’s embedded Linux products can replace a traditional RTOS.
Montavista LinuxFigure 1 clearly demonstrated Montavista Linux product development process, where there is such need to be addressed several aspects.
Figure 1 Montavista the course of development
HardHat Linux
Prior to 2002, Montavista’s Linux product name is called HardHat Linux (The name is also the first in the open source community and university inside spread), HardHat the origin of the name may need to distinguish it from the market’s reputation is already very large redhat, said that Montavista of Linux is a real-time and embedded Linux, because bar. Since the creation of the initial positive wave of the Internet economy, Montavista the initial business model and other open-source software, is a free software, but charge for service and upgrades.After 2002, the beginning Montavista Linux 2.0 from the Linux industry, which widely used instead of the subscription model, that is, pay for product, receive support during your subscription, upgrades and patches.
The three versions of Montavista Linux
Montavista Linux currently has three versions, professional edition – known as the Professional version (the pro), is mainly directed against a variety of general-purpose embedded applications, it is also Montavista Linux’s core products, other versions are also developed by this version of the, carried grade edition (abbreviated CGE), also known as the telecommunications Linux version, this version is the basis of the professional version adds a reinforced core, accident handling, high possibility of dynamic loading characteristics, in line with OSDL specifications telecommunications Linux (also known as CGL specification, http://www.osdl.org-this body from the Linux Foundation recently merged), CGE supports advanced computing platforms such as ATCA advanced hardware technologyMobilinux is important Montavista one of the flagship product in 2003, in the professional version of Montavista developed a program called consumer electronics (consumer electronic edition-called CEE) version, CEE due to Motorola smart phones based on Linux operating system is known for abroad, 2005 CEE end of the year and then be re-developed and become known as Mobilinux specifically for the mobile phone market when compared with the previous version, Moblinux increase in handheld devices that can greatly reduce energy consumption in dynamic power management, Linux system, quick start, size, optimization techniques and a variety of measurement and analysis tools.
In the past six years, which Montavista Linux there are two important stage of development, first, the evolution of the kernel, version 4.0 has been previously Montavista Linux is to use the 2.4 version of the open-source kernel, such as the 3.1 version is used in 2.4.20, version 4.0 After, Montavista Linux uses the popular 2.6 version of the core technology. Second, the tools of evolution, Hard Hat Linux tools, traditional Linux command line, after the Montavista Linux version 3.0, an increase of the integrated development environment (IDE), when used in KDE, 3.1 after the upgrade version of Eclipse, which is a current feature the most complete integrated development environment.
Montavista Linux real-time
Montavista has been insisting in an open and compatible with the kernel development community under the prerequisite of growth and development of real-time Linux technology and apply it inside the Montavista Linux products, such as Montavista Linux 2.1 version has been achieved Preemptible kernel and Realtime scheduler, and thus fundamentally change the regardless of the traditional Linux processes and threads that can not be much time to seize possession of and in accordance with priority scheduling history, when the 3.1 version, Montavista the time is also being developed in the 2.6 kernel among the 0 (1) scheduler and high-resolution timing device transplantation (backpor) to 2.4 3 Montavista Linux 3.1 kernel version, so that the use of Linux for embedded software development, the earliest use of the user to the most advanced real-time Linux technology, at the same time prepare for future upgrade to 2.6 kernel is fully is compatible with the preparation, in 2005 Montavista in the development of 2.6 kernel 4.0 version of the initial stage, in the open source community to create a real-time Linux project and community collaboration through the development of Montavista products in the 4.0 years of the Linux 2.6 kernel to achieve RT-Path technology. Montavista technical experts from the traditional embedded field, real-time technology and requirements are very understanding, Montavista convinced that the real-time Linux-based open-source can meet the needs of real-time embedded systems, past practice has been proof of this 1:00.
Montavista Linux professional 5.0
Montavista Linux professional 5.0 (referred to as pro 5.0) 5.0 family, the first product in February 2007 began with Beta version, released in stages in April as part of an embedded processor reference platform supported versions, pro 5.0 contains the latest release of marks Linux technology, the arrival of a new generation of embedded software platforms, pro 5.0 is based on the current version 4.0 incorporates an advanced Linux kernel, applications and tools made of technology development. The following analysis from four aspects;
DevRocket 5
DevRocet 5 is based on a complete embedded Eclipse integrated development environment, which uses the latest CDT expansion and management techniques, and have a more convenient editing – Compile – remote debugging process, more can be inserted tool chain, DevRocket 5 also in the absence of target hardware can support the case of a virtual development environment. Simply put you can DevRocket understood as a Eclipe and a series of plug-ins under the framework of the composition of software tools, this tool includes C / C + + development and remote debugging (kernel and user mode), applications and systems tracking, system performance analysis , remote system management, systems management platform for image-based CVS version of the software management, and different from the previous version, DevRocket 5 plug-in the form of an increase of four tools: (1) to detect memory leak tools; (2) Performance statistical and analytical tools; (3) can be observed throughout the system kernel and application memory to-use tools, shown in Figure 2; (4) visualization kernel and user mode applications, tracking tool. Read LLTng through Eclipe graphical display of the trace file, different from the past DevRocket. The new version allows users to use other companies or open-source Eclipe framework to Montavista tools to install the plug-up that allows users to feel the joy of using the latest technology. Theory terms, in obtaining a valid license after DevRocket 5 could support the previous version of 4.0 or even 3.1 in all Montavista Linux version of the product.
Figure 2 DevRocket5 additional tool in observing the whole system kernel and application memory usage
The new kernel and application
Pro 5.0 to use a stable and the new 2.6.18 kernel, LSB3.0 compatibility, security features, IPV6 certification, real-time kernel and user-state technology, including support for Priority Queuing, Priority Inheritance, Robust Mutexs and the new HR Ktimers, I / O, and network to support additional device drivers, such as, SDIO, USB OTG, Bluetooth (planned mobilinux 5.0 inside), 802.11g WiFi, support for ARM Jazelle (ARM release java virtual machine optimized hardware acceleration technology, the purpose is to increase the java Start the application running and reaction speed). pro 5.0 also includes a Montavista previous CEE3.1 and Mobilinux 4 which uses XIP technology, which is a Linux system boot can improve the speed of technology, which means pro 5.0 will be suitable for addition to mobile phones consumer electronics applications.
Reduce the size of the technical
In the 5.0 version, Montavista significantly improved the size of optimization techniques, the use of advanced Linux Tiny and can support NPTL, ARM EABI of uClibc, with the ARM Thumb mode after the application of the use of uClibC dimensions can be reduced by nearly 50%, that is just the application part If taking into account the file system optimization, it is possible to 70-80%, simply speaking, a standard Linux has about 14M, through the 5.0 version (or use Mobilinux 4.1-it already contains uClibc) can be fully optimized to the 3M or so.
Perfect quality assurance system
Currently Pro 5.0 kernel is 2.6.18 baseline add about 1,500 of the patch (this number is still as new hardware support and continuous increase), of which nearly 30-40% of the patch, they are jointly and severally relationship, not only if you modify the other one may have to change. Re-refined look at the entire code Pro 5.0 is 2.6.18 kernel code, non-mainstream kernel code, such as ARM and MIPS branch code, RT patches, 2.6.19 the bug on 2.6.18 as amended backport, Montavista development of internal self – and amendment of the software modules (typically each issue you want to modify more than 1000 bug) composed of five parts, and then go through 35000 for each build automated test, such a large software project is hard to imagine simply to a few Linux Engineer their completion, Pro 5.0 so works also in perfect quality assurance system developed under the 2.6 kernel in the past two years and five years experience in the crystallization of 2.4 kernel, more importantly, by the tens of millions of dollars in products based on Montavista Linux certification given Pro5.0 a good quality product basis.
The development trend of embedded Linux technology
Recalled Montavista Linux development process and analysis pro 5.0, after a number of technical features, and then we look at the current market, commercial and open source embedded Linux, the status quo, we can easily see that the trend of the future of embedded Linux technology trajectory:
Linux tools will become very popular
Open-source Eclipes framework has become the de facto enterprise software and embedded software development standards, not only received the software and system vendors recognized and received the support and participation of equipment manufacturers, Motorola has recently announced it has joined Eclipes Foundation to participate in a device Software Development Platform (DSDP) project to develop a Linux tool for mobile-TmL is a good example. Based on Eclipes tools for embedded development framework will be the future of embedded Linux or other embedded operating system and standards of the mainstream development platform for embedded Linux tools for the present and future will be mainly aimed at Linux command-line tools for the improvement and upgrading of the development of new analytical tools, configuration tools, performance testing tools and debugging tools. For example the above-mentioned Montavista Devrocket5, support and cooperate with BDI2000 the Linuxscope, Workbench, and Timestorm.
An important tool to promote Eclipe popular Linux-embedded non-technical reasons, comparing with other software, the software industry needs better tools to develop, debug and test, and the empowerment of Eclipe is more compatible in a commercial tool developed by a commercial royalty-free mode sales and support.
Embedded Linux Software Platform into Application
As commercial Linux server software companies, embedded software companies have realized that they should be more in the Linux kernel for application software development, integration and testing in more effort to meet the users of products using embedded Linux listing requirements as soon as possible, making embedded Linux contrast to Microsoft’s Windows Mobile more competitive, that is, Linux software, middleware, different companies will be increasingly emerged in product differentiation and value.
Montavista products beginning in the 4.0 already has a very clear middleware layer – the application software interface, as shown in Figure 3, the middle layer includes the GTK/X11 graphics library, more than 200 user-state application modules, IPV6, and IPsec / IKE, Web services networking utilities, WiFi in the network protocol. The Montavista application-oriented telecommunications and mobile phone version of the CGE application Mobilinux has been involved in some, such as inside Mobilinux 4.0 increases the dynamic power management support and facilitating the application of strategic management, DirectFB graphics applications for fast graphics library and just mentioned The small size applications library uclibc, pro 5.0 and Mobilinux 5.0 will increase its support for WiFi security and management, Mobilinux 5.0 There are plans to support the complete Bluetooth protocol and application, these modules while the bottom drive is inside the kernel, but quite a lot of The module is at the application layer of the.
Figure 3 Montavista Linux in the middle layer
Of course, whether it is pro, Mobilinux, CGE, still can not be called is a complete Linux application platform, you can say that they are nothing more than SUSE and Redhat have been closer to the common embedded and telecommunications embedded Linux applications, but from the consumer electronics, such as cell phone use is still a considerable distance from the current commercial companies, the open source community and industry organizations are also making more efforts, such as Trolltech, Access, LiPs.
Embedded Linux and open towards the close to the standard direction
More information indicates that embedded Linux is to a standard direction, particularly in core areas, such as Pro / CGE / Mobilinux 4.0 using the standard 2.6 kernel RT-patch achieved a Linux host of real-time requirements, Pro 5.0 supports LSB3 .0, Linux in telecommunications have OSDL CGL standard, consumer electronics, there are CELF and the latest LiMo-one created by the Motorola mobile Linux standard platform for organizations to create a standard, Montavista as a founding member of OSDL is committed to tracking and follow the CGL specification , is the only certified products through the CGL in the recent 3GSM conference, Montavista have, and LiMo in close contact with them. More importantly, embedded Linux developers can not be difficult to separate from linux open source community, and actively participate in community projects, maintenance of community projects, to create a good community-based projects for embedded Linux is the correct wayFor example Montavista development preemptable kernel and real-time schedule (Rober love) came to be transplanted and incorporated into the 2.6 (0) 1 schedule and the preemptable kernel as the standard 2.6 kernel, the new high-resolution timer (HRT)-Ktime is Montavista maintenance, have also been accepted by the 2.6.18 kernel will also be in the Pro 5.0 after various products containing and will support a variety of embedded processor hardware platform.
Conclusion
Linux and embedded Linux software in the past five years has become increasingly common for the IT industry, semiconductor companies, embedded system recognized and accepted, it has become an alternative to Microsoft Windows and many important traditional RTOS operating system . Linux kernel and the basic components and tools are already mature software, industry-oriented applications and equipment tools for embedded Linux and embedded Linux operating system platform is the inevitable trend of future development, tracking Linux community development, in line with standards, follow the opening are the main trend, embedded Linux is no exception. (T002)
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