Arm Wearable Computer Underlying The Design Of Software Systems

In the modern logistics jobsite, workers generally use hand-hold data terminal to complete cargo information collection, processing, transmission and other operations. To enhance the performance and improve the efficiency, a wrist-worn wearable computer system (WWWC) is designed in this paper. It uses a PXA270 processor and embedded Linux-based architecture with a number of advantages, such as low power, and small size, easy of use. It also integrates flexible data collection and communication methods such as barcode scanning, RFID, WiFi and Bluetooth technologys.The platform software is a software layer lies bettwen hardware and application software (for example, GUI),it contains those software packages:Bootloader,Linux and root file system.The design of bottom software affects the circuit development and the quality also has grave implications for the stability and efficiency of the up-application.The bottom software lies bettwen plays an important part in the entire system, it has undertaken the role to connect application software (for example, GUI) with hardware.The design of bottom software not only affects the circuit development, but also has grave implications for the stability and efficiency of the upper-application.This paper introduces the bottom software design from the following aspects.1) In this paper, the ARM+Linux embedded structure of the WWWC and the hardware platform based upon PXA270 microprocessor core are analyzed. At the meantime, the layered software design resolution is proposed.2) The general design methods of Bootloader are discussed. And then the U-Boot porting scheme is realized and the critical techniques about Bootloader development are analyzed.3) The Linux 2.6.9 kernel porting methods based upon PXA270 processor are presented, and the design method of LCD module and NOR Flash programming assistant are also illustrated.4) The major factors which caused system slow-down are analyzed, and then detailed fast boot solutions are put forward, which includes Linux kernel, root file system and user space optimization methods. 5) The testing scenarios of several important modules are introduced, those include Bootloader, LCD module, and NOR Flash programming assistant.In this paper, the system platform software development is realized in a bottom-up approach and a great fast boot optimization is made. The platform software performs well in the real WWWC mainboard.Currently the development of software and hardware of WWWC is finished and the system is now under refine period.