The Migration And Implementation Of Embedded Network Operating System Based On UC/OS-Ⅱ And LwIP

Based on the introduction of related techniques of embedded system software andhardware, this thesis focuses on the migration and implementation of an open sourcefashioned embedded real-time operating system uC/OS-II on ARM-based microprocessor.At first, this author analyzed the uC/OS-II source code, thoroughly read and researched onthe relevant part of the core code to port; meanwhile made comprehensive grasp with theARM architecture. This thesis finally made specific porting of uC/OS-II on ARM-basedmicroprocessor. Whereas the uC/OS-II is an evolving improvement of embedded real-timeoperating system, along with the updated version of its contents, there are many variationstransplant. This thesis examines the uC/OS-II in the transplant process involves possibledifferences between different versions of content transplantation, especially to improve theproblem of transplant methods.For embedded devices to exchange information directly with Internet, TCP/IPprotocol set support is needed. Embedded systems have a small core, and have dedicated,simplified, and real-time requirements, demanding lower power consumption and harshenvironment conditions, so the traditional TCP/IP protocol stack is not suitable fortransplantation into embedded systems. This thesis has also discussed the transplantationmethods of LwIP, a small TCP/IP network protocol stack suitable for embedded systems,into the uc/OS-II operating system. Because LwIP has not used the system calls and datastructures related with uc/OS-II operating system, so we adds a encapsulation layerbetween LwIP and operating system for the services of operating system. In the other hand,an interface has also been realized between the operating system emulation layer and theLwIP underlying layer in the transplantation. Operating system emulation layer providesan interface to the protocol and operating system to enable protocol transparent to theoperating system, and LwIP underlying interface provides various drivers for the differenthardware components realizing system initialization, card initialization, thread receiving, data packets reading and sending.Finally, the thesis has designed a testing framework for the transplanted system, andconducts the testing to the embedded Web Server Application on the ARM developmentboards and transplanted μC/OS-II operating system. Test results show that the transplantedsystem can properly work, and realize the basic network functions.