隨著智慧型手機及平板電腦的崛起，讓現在的消費者對於消費性電子產品有更進一步的需求以及期待，除了開發商提供友善的圖形化使用者介面之外，應用程式的執行效能更是得到使用者的關注，且現在智慧型手機的蓬勃發展，在多元化的功能需求底下，圖形化介面與多媒體應用是現在使用者的重心，應用程式的效能更受到重視，因此開發者應該重新審視，如何將多媒體軟體開發在有限的資源中呈現最高的效能，這是更重要的一環。
目前市占率最高且為開放式的作業系統，本論文以Java為基礎建構而成的Android系統為主，網路上資源雖然豐富，但是沒有完整的移植過程，讓移植Android系統變的複雜且困難，而本論文使用ARM Cortex-A8為核心的BeagleBoard-xM移植Android系統，此開發版價格低且豐富的多媒體周邊裝置，非常適合執行圖形化介面系統在此平台上，並在這提供詳細的移植流程，重要的周邊裝置的檔案設定修改，使移植Android的過程直接完整，供有興趣的人參考。
本文除了探討如何自行移植Android系統至嵌入式平台Beagleboard-xm外，因為圖形化介面與多媒體應用的效能受到重視，為了要有圖形化介面，以Java建構的Android系統為主，且本論文使用JPEG壓縮影像中使用的DCT(Discrete Cosine transform)以及處理音樂資料使用的FFT(Fast Fourier Transform)兩個應用來做效能比較， JNI結合C的程式在兩個應用中以重啟方式測試，分別提升了63%及47%的速度；而兩個應用程式於背景執行的狀況，Java雖有加速效果，但依然比不過JNI結合C的部分提升，因此運用C函式庫來呼叫嵌入式平台的硬體驅動或是多媒體應用，能提升整體系統執行效能。

As the trend for risen of smartphones and tablets, which makes the consumers nowadays require further and expect more on the consumer electronics. Beside GUI (Graphical User Interface), efficiency of program is getting concerned from users. Beneath the diverse functional requirement, GUI and multimedia application are end user's focus. Thus, the application performance is much more emphasized. So the program developers should take it seriously. It’s very important that how to develop a highest efficient program in a limited resources condition.
Our thesis is based on an Android system which is constructed by Java. Android is the most popular open source operation system on mobile, but companies do not release their porting guide generally. On the other hand, academia has many hardware resources, yet lacking experiences of porting Android system. There're so many resources on the internet, but contents is uneven. Some of them do not have specific procedures, which makes porting Android system more complicated and difficult. The thesis chose ARM based Cortex-A8 BeagleBoard-XM as kernel development kit for porting Android. Main reasons are the cost and rich peripherals for multimedia, which makes it appropriate to execute GUI on the platform. In addition, information of environment porting, procedures, issues, and solutions are provided in detail. Especially, configure peripherals settings in kernel, which results in the success of peripheral activity by kernel. I believe this's the prerequisite for people who tries to learn porting platform.
The thesis is based on porting Android on the Beagleboard-XM Embedded platform and analyze more clearly by below procedures. Based on Android system be constructed by Java. The most often used in JPEG image compression, DCT (Discrete Cosine transform) operation used to compress JPEG images, and FFT (Fast Fourier Transform) operation used to process audio data for the performance comparing. In DCT aspect, program in conjunction of JNI and C start to execute each time, DCT (Discrete Cosine transform) operation used to compress JPEG images could obtain 63% speed faster compared to execution by Java coding, when the conjunction of JNI and C start to execute each time. As the consecutive execution, though Java could maintain the same speed, the conjunction of JNI and C which still boost 25% speed. The FFT(Fast Fourier Transform) operation used to process audio data could boost 47% and 2% speed as well, when starting to execute and consecutive execution. Even the hardware drivers and multimedia libraries of embedded platforms are usually coded in C language. Therefore, Java adopts JNI (Java Native Interface) which calls the C library for program development, in order to improve the system execution performance.

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