Supporting Object Module Level Library Customization with Symbol Linking Technique – A Case Study on Linux Embedded Systems

• Main Authors: Cheng-Chiang Liu, 劉正強
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/92572108868575755861

碩士 === 逢甲大學 === 資訊工程所 === 97 === To void the same function lives in different applications, putting many kinds of functions into a library is the common way on modern systems. Considering the restriction of system size, embedded system does not need this general and huge library, but these is usually lack of configurations for reducing the size of library. In this thesis, we will try to gather external symbols in applications to find the needed object files of library, and then using this information to re-build and customize a new library for target embedded system. To giving the extendable ability for the re-build library, when needing a new application we will also build and load part of library that was not in the previous re-build library. In order to support many kind of computer hardware, when first powering on, it must using BIOS to detect and initialize hardware for X86 computer, then BIOS gives control to a Bootloader which will load and boot operating system. Because of the old fashion designs of BIOS, we cannot easily add any kind of service or function which we wanted in boot up stage. To break this kind of restriction, in my thesis will using the open source Coreboot project to replace BIOS, combining with Linux operation system, using symbol searching to re-build system library, building the part of library when adding new applications, and implementing a extendable functions of bootloader. The re-building system library tool will focus on uClibc which often been used for embedded system. For extending functions, I will build a client-server system to download the functions to target board through Internet, and the extendable functions can be open source applications, drivers or kernel modules. Server managing these functions through user interface, so it can easily create and manage these functions. Finally, bewaring the size restriction of BIOS ROM chip, the whole client system will follow the concept of implementing an embedded system to provide service as many as possible.