Porting Of Embedded Linux System And Optimization Of Kernel's Start-up Time Based On I.MX6 On Vehicle

With the development of automotive electronics and the improvement of people's consumption level, China has become the world's largest auto market, There will be huge market in the smart vehicle information system. Now the vehicle information system are moving in the direction of combining navigation system,multimedia system,Bluetooth phone, network and interconnection with phone into one product. In order to support so many functions, we need the support of powerful processor and operating system.In order to provide a stable working environment for the complex application, this paper researches the porting of embedded Linux system based on i.MX6 on the vehicle information system. The i.MX6 series processors with powerful multimedia, high performance and low power consumption are based on Cortex-A9 architecture, they are designed for automotive multimedia application. This paper analyzes the character of several embedded operating system, and proposes the solution of porting by using U-Boot to boot the kernel stored in the EMMC. According to the solution, the main job of this paper is completing the porting of U-Boot, Linux kernel and root file system.In the embedded Linux system, the Linux kernel cannot be run directly, it should be boot by the Bootloader. Bootloader's main job is completing the initialization of hardware and software environment to boot the Linux kernel. At first, this paper researches the startup process of U-Boot and focus on the porting of architecture level and board level. Then completes the porting of U-Boot.Second, this paper researches the porting of Linux kernel. During this section, the main job are configuration and tailoring of kernel, optimization of the kernel start-up time and design of the device driver. In the part of kernel's configuration and tailoring, we analyze the compilation rules of the kernel to configure the kernel and compile the kernel. In the part of kernel's start-up time optimization, we propose the way of booting the non-compressed kernel. We take measures on U-Boot and kernel to reduce the kernel's start-up time at the same time. In the part of device driver porting, we analyze the architecture of the related driver and complete the design and porting of the driver.The Linux kernel must mount the root file system, we make up the root file system by using BusyBox at last. We use the net file system in the system test.After testing, the embedded Linux system of vehicle can be run normally in the hardware platform. Power control driver, touch screen driver and audio driver run normally and achieve the desired goal. The non-compressed kernel can be booted normally, and after we take measures to optimize the U-Boot and kernel,the start-up time of kernel has been reduced 7.31 s compared to the before.