Embedded Linux tax settlement system

Embedded Linux settled in the tax system-Linux general technology-Linux programming and kernel information, the following is a detailed description. The work of the tax system is characterized by high mobility and frequent on-site office work. Therefore, the use of PDA can greatly facilitate the work of tax officers. Beijing gongchuang open source limited by share Ltd developed Based on Embedded Linux tax PDA (T-PDA) solution, has achieved good results.

1. application background

Tax personnel use T-PDA built-in IC card reader and embedded database, combined with the corresponding tax industry application software, you can handle the tax business. With the built-in Modem, the tax terminal can log on to the existing tax Industry Application Server and upload and download data. The T-PDA and PC can communicate with each other through the RS 232 interface or infrared to complete the necessary settings and information synchronization.

The main body of the T-PDA software system is CCLinux 2.0 embedded system. CCLinux is an embedded Linux operating system for embedded application devices launched by Beijing co-founder Open Source Software Co., Ltd. (hereinafter referred to as Beijing co-Ltd, mainly including Linux-based embedded operating system core CC-OS, embedded Graphics System CC-GUI, embedded graphics applications and embedded integrated development environment CC-SDK/CC-ETK.

2. System Design Principles

(1) Make full use of existing software resources to maximize the hardware features.

(2) The system adopts a hierarchical structure design. We try our best to keep the upper-layer software independent from the hardware and increase the portability of the entire system.

3. Design Scheme

(1) Operating System Design Plan

Ccs-os is the core of an embedded Linux operating system jointly developed by Beijing. CC-OS is a highly customizable system that can be based on the actual needs of the T-PDA system to complete the function of irrelevant functional modules from the kernel cut off, to minimize the size of the kernel, through modular processing and automatic power management, the resource consumption of the actual system is minimized. CC-OS operating systems support Intel's StrongARM embedded microprocessor.

(2) Graphic System Design Scheme

The cc-gui is an Embedded Graphic System developed by Beijing. It has the following features:

① The size is small, and the size of the entire CCGUI graphic environment is less than 700KB.

② Provide simulation implementation support. You can develop applications on the desktop X System and simulate the running status of the applications on the embedded system.

③ Supports multi-task and Chinese GB2312.

④ Provides a large number of complete controls. It is convenient for users to write embedded applications.

According to the specific needs of the T-PDA, the work to do on the existing graphics system is as follows: provide a table manager to meet the user's needs; Provide a user to upgrade the application interface; the combination of the CCGUI Graphics System and the target platform operating system; provide the hardware device drivers required by the CCGUI Graphics System in the target platform operating system.

(3) Embedded Database Design Scheme

In this solution, the T-PDA and tax system servers constitute two levels of database application systems. T-PDA as a mobile database system, some data can be temporarily input and maintenance operations; the tax system server to undertake the final data maintenance work; the two through appropriate policies to maintain synchronization. The system integrates the Embedded Database System of dtcenter. The database system has a small kernel (the initial memory usage does not exceed KB) and a database can be customized freely. It can customize system functions and convenient query functions based on specific applications or industry characteristics, supports SQL query statements and other features.

In addition, in the Chinese Character Input design scheme, Beijing is used to create a self-developed function, complete Chinese handwriting input and full spell input. In terms of integrated development platform design, it provides a powerful integrated development environment for applications, allowing users to easily develop applications running on the target platform on the development platform.

The Development Environment jointly developed by Beijing can be used to simulate the target system. The system can be completely simulated, including the basic system, such as embedded Linux core, Glibc library, basic operating environment and device drivers, graphics systems and System Extension components (such as embedded databases), to accelerate application software development; A graphical user interface is provided, so that you do not need to remember the complex command set in the character interface, and the entire integrated development environment is simple and easy to use; encapsulate the underlying process, users only need to care about the Upper-layer function implementation.