What does a platform phone mean?

SymbianS60 Smart Phone Platform Introduction Thursday, July 09, 2007 10:4 1 In recent years, smart phones with some functions of handheld computers have developed rapidly. Smart phone means a mobile phone product that uses an operating system with an open programming interface to facilitate software developers to develop various third-party software for it to enhance its functions. At present, the mainstream operating systems used by smart phones can be divided into four categories: Symbian, Windows Mobile, Linux and Palm. Symbian mobile phone adopts the design of separating the bottom operating system from the user interface. Common user interface platforms based on Symbian are S60, S80, S90 and UIQ. With the strong support of Nokia, S60 platform occupies an important position in the smart phone market.

Since 2002, S60 has experienced more than three years of development, with several versions: version 1 (such as 7650), version 2 (such as 6600), version 2 FeaturePack 1 (such as 76 10) and version 2 FP2 (such as 66865438). In the second version of FP3 and previous versions, although every upgrade will introduce some compatibility problems, the main software (this article refers to S60 software package. Sis extensions, excluding Java software) are generally acceptable. Among them, the compatibility of upgrading 1 to version 2 is serious, but it is acceptable.

However, once the user buys the upcoming mobile phone using S60 version 3, it will be found that the existing third-party software supporting S60 version 1 and 2 cannot run on the new mobile phone or even be installed. These mobile phones include 3250, N7 1, N80, N9 1, N92, E60, E6 1, E70, and there will be more in the future. Looking at the familiar S60 interface on the mobile phone screen, users may be at a loss. It is true that the display interface of S60 third edition is very similar to the first two editions, and the main improvements are as follows: multiple resolutions, support for horizontal and vertical screens (not the fundamental reason for compatibility, think N90), the scroll bar is changed from the arrow on the bottom menu to the right line, the Jiugongge icon is changed to 3x4, and the running program displays a small circle in the upper right corner of the Jiugongge icon. However, what is hidden under the basically same user interface is the huge difference between different versions of the operating system.

S60 version 1 uses Symbian 6. 1 operating system, the second and second versions FP 1 use Symbian 7.0s, the second version FP2 uses Symbian 8.0a, the second version FP3 uses Symbian 8. 1a, and the third version uses Symbian 9. 1 (. There are only 77 10 mobile phones based on S90 platform, using Symbian 7.0s operating system). Since Symbian has introduced many brand-new functions since the 9th edition, its compatibility with previous editions has been completely destroyed. In other words, the compatibility problem of S60 is caused by its underlying Symbian operating system. Here are three major new features that pose compatibility issues:

(1) In developing tools of Symbian 8. 1a and before, the compiler uses gcc for ARM. Compilers used in 9.0 and later versions are RVCT supporting ABI standards. Indeed, under the same hardware conditions, the use of RVCT makes the new system faster and saves more memory. However, there are many differences between executable files and compiled DLL files, which is the main reason for system compatibility problems.

(2) Symbian 9.0 and later versions introduced a new system security model. As more and more personal information (such as phone books and business secret files) will be stored in smart phones, it is necessary to prevent malicious software or viruses from stealing this information or consuming users' communication expenses. Users will notice that all files of a software installed in the previous system will be stored in the \system\apps\xxx directory. In Symbian 9.0 and later systems, different files in a software will be stored in different directories. Executable files (. It used to be exe. App) are placed under \sys\bin, resource files are placed under \resource, and all private data of each software are placed under \ private \; Directory, other directories are directories of all software. Users \ sys\bin and \resource cannot be changed, and the executable file can only be copied by the installer. \ private \< software security number >; Can only be accessed by the software corresponding to the software security number. The executable file introduces the competency model. In order to obtain some functions, such as accessing the user's phone book, sending short messages, and modifying mobile phone settings, it is necessary to obtain the digital signature of the executable file from Symbian company or Nokia company. The system also has the function of preventing executable files from being edited. Using a card reader to install the modified software package or modifying the \sys\bin directory of the memory card will be found by Symbian system. By introducing these features, the security of the system is greatly improved, and all kinds of private data can be safely stored in the mobile phone. However, the introduction of system security model is another important reason for system compatibility problems.

(3) Symbian 8. 1a and previous versions all use EKA 1 kernel, and 9.0 and later versions use EKA2 kernel. EKA2 comprehensively improves the task scheduling algorithm of EKA 1 and fully supports real-time. Real-time is the basic requirement for the system to support some high-bandwidth and high-priority tasks. These tasks include VoIP and high-speed video on demand. EKA2 can also take advantage of the latest CPU features. However, some differences between EKA2 and EKA 1 will lead to some compatibility problems.

Symbian and Nokia must have made a lot of trade-offs before launching these features, because these new features will make S60 version 3 completely incompatible with the previous version. Finally, it is decided that for the long-term development of Symbian and S60 systems, it is worthwhile to endure the pain of software compatibility, such as supporting VoIP, online MP4 high-speed decoding and playing, and supporting business people's security requirements for application software. In addition, Nokia has promised that the fourth edition of S60 will be compatible with the third edition.

In order to make their own software run on the S60 3rd Edition platform, every software vendor must modify their own software and launch a new version supporting S60 3rd Edition. Fortunately, this work is not laborious. Make a few changes to the source code, compile it with the new compiler mentioned above, and a new version will be born after the test passes. I estimate that a large number of S60 version 3 software will appear immediately after the new mobile phone comes out. In addition, due to the above reasons, the new version of the software supporting S60 version 3 cannot run on the existing S60 version 1 2 mobile phone. Therefore, in the future, various third-party software may develop two versions in parallel, one is S60 version 1, and the other is version 3. However, the third edition of S60 is definitely the focus of Nokia's future development. In the future, S60 new mobile phones will basically be the third edition, and the market of S60 1 2 will gradually die out. Moreover, the market of S40 will shrink, and only the lowest-end mobile phones will be used. S60 Version 3 will be the most important platform for Nokia mobile phones in the next few years, covering both low-end and high-end mobile phones. So don't worry about the future of the third edition of S60.