Research And Porting Embedded Linux Kernel Based On ARM Cortex-A9

The ARM architecture processor because of its low power consumption and excellent performance,extensive use in mobile phones,industrial control and consumer electronics and other embedded related areas.Due to its open source code,excellent performance,the system can be cut on demand and support all kinds of CPU architecture and many other advantages,Linux kernel become the most widely used operating system on embedded devices.Linux kernel porting is at the core of embedded Linux system development work.Linux kernel in the evolution of the process has been abandoned some outdated old code,adding some new features.A significant feature of the ARM Linux kernel is the introduction of a device tree from the 3.x version,which reduces the redundancy of board-level files in the ARM Linux kernel.U-boot is one of the most widely used Bootloaders for embedded systems.Since v2014.04 version,U-boot added device tree to support the ARM Linux kernel,making it possible to use the same device tree file in the ARM Linux kernel and U-boot.In this paper,using Samsung Exynos4412 chip development board which based on ARM Cortex-A9 architecture as the hardware platform,study the key technology of how to porting the ARM Linux kernel and U-boot to ARM platform.The specific research and porting work is as follows.Research the grammar of the device tree and its usage on the ARM Linux kernel.Set up the Linux kernel development environment,including Ubuntu system,cross compiler tool chain,Samba,version management tools Git,etc.Analysis of the startup process of the Exynos4412 chip,U-boot boot process,U-boot device driver model,Linux kernel configuration compilation and its startup process.Making embedded Linux root file system.Finally,successfully porting the new version of U-boot(u-boot-v2016.11)and Linux kernel(Linux-4.4)to the target development board.Through analysis and study how to porting the new version of U-boot and Linux kernel to the Samsung Exynos4412 chip development board which based on ARM Cortex-A9 architecture has reference value and significance for porting new version of U-boot and Linux kernel to other ARM architecture platform.