The Analysis, Transplant And Improvement Of An Embedded OS Based On ARM7

Along with the development of computer science, embedded technique has become much more important, and it has become the focus of research in recent years.The ARM7TDMI is a RISC processor that has high efficiency and low depletion, and its kernel, S3C44B0X, is a high price ratio 16/32 microprocessor. It is designed to adapt to the development of the embedded product.μC/OS-Ⅱ is a completely free embedded operating system. It is has free code, can be transplant, can be cut, can be solidify and supports multitasks. It's a simple embedded OS that only support static task schedule.Along with the development of embedded OS, it is required to have multifarious task schedule arithmetic.This paper focuses on how to realize the RMA and EDF arithmetic.First, the papers analyses the initialization and the memory distribution of μC/OS-Ⅱ and described how to use to the OSTCB. It also analyses the block's function and applied situation.The second, this paper completes the transplant of μC/OS-Ⅱ on the chip of S3C44B0X. It describes the condition and the preparation of transplant. It also describes the development of OS_CPU_C.C, OSCPU.H, OS_CPU_A.ASM.Finally, it gives an improvement of the scheduler's arithmetic. The task scheduler needs to distribute the PRO to the ready task .In order to forbid avert the ready task's PRO order frequently, we use the method that the computer maintains CACHE unanimous with the main memory that is the write back method to ameliorate the static schedule method.In the μC/OS-Ⅱ OS ,we completed the RM EDF, EFDF arithmetic and we give an evaluation in the end.