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Brief History of Embedded Device Programming For a long time, cell phone developers comprised a small sect of a slightly larger group of developers known as embedded device developers. Seen as a less “glamorous” sibling to desktop—and later web—development, embedded device development typically got the proverbial short end of the stick as far as hardware and operating system features, because embedded device manufacturers were notoriously stingy on feature support.32411
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Embedded device manufacturers typically needed to guard their hardware secrets closely, so they gave embedded device developers few libraries to call when trying to interact with a specific device. Embedded devices differ from desktops in that an embedded device is typically a “computer on a chip.” For example, consider your standard television remote control; it is not really seen as an overwhelming achievement of technological complexity. When any button is pressed, a chip interprets the signal in a way that has been programmed into the device. This allows the device to know what to expect from the input device (key pad), and how to respond to those commands (for example, turn on the television). This is a simple form of embedded device programming. However, believe it or not, simple devices such as these are definitely related to the roots of early cell phone devices and development. Most embedded devices ran (and in some cases still run) proprietary operating systems. The reason for choosing to create a proprietary operating system rather than use any consumer system was really a product of necessity. Simple devices did not need very robust and optimized operating systems.
As a product of device evolution, many of the more complex embedded devices, such as early PDAs, household security systems, and GPSs, moved to somewhat standardized operating system platforms about five years ago. Small-footprint operating systems such as Linux, or even an embedded version of Microsoft Windows, have become more prevalent on many embedded devices. Around this time in device evolution, cell phones branched from other embedded devices onto their own path. This branching is evident when you examine their architecture
Nearly since their inception, cell phones have been fringe devices insofar as they run on proprietary software—software that is owned and controlled by the manufacturer, and is almost always considered to be a “closed” system. The practice of manufacturers using proprietary operating systems began more out of necessity than any other reason. That is, cell phone manufacturers typically used hardware that was completely developed in-house, or at least hardware that was specifically developed for the purposes of running cell phone equipment. As a result, there were no openly available, off-the-shelf software packages or solutions that would reliably interact with their hardware. Since the manufacturers also wanted to guard very closely their hardware trade secrets, some of which could be revealed by allowing access to the software level of the device, the common practice was, and in most cases still is, to use completely proprietary and closed software to run their devices. The downside to this is that anyone who wanted to develop applications for cell phones needed to have intimate knowledge of the proprietary environment within which it was to run. The solution was to purchase expensive development tools directly from the manufacturer. This isolated many of the “homebrew” developers.
嵌入式设备编程的简要历史
很长一段时间以来，手机开发人员们组成的一个略大的开发商被称为嵌入式设备开发人员，视为一个“迷人的”兄弟姐妹少桌面和后来的web开发,嵌入式设备开发经常会有不公平的待遇，因其硬件和操作系统的特性，他们的制造商是很难舍得花大成本的。论文网
嵌入式设备制造商通常需要保护他们的硬件的秘密,所以他们给嵌入式设备开发人员数库调用时试图与特定的设备进行交互。嵌入式设备不同于台式机,嵌入式设备通常是“计算机芯片上。“例如,考虑你的标准电视遥控器;它不是真正视为一个压倒性的技术复杂性的成就。任何按钮被按下时,芯片对信号的方式已经被编程到设备。这使得设备知道什么期望从输入设备(小键盘),以及如何应对这些命令(例如,打开电视)。这是一个简单的嵌入式设备编程形式。然而,不管你信不信,这些简单的设备肯定是与手机设备和早期发育的根源。大多数嵌入式设备运行(在某些情况下仍然运行)专有的操作系统。选择创建一个专有的操作系统的原因,而不是使用任何消费系统是一个产品的必要性。简单的设备不需要非常健壮的和优化的操作系统。