Digi 9P 9360/9750 manual Root File System Types

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R o o t F i l e S y s t e m T y p e s

Root File System Types

C H A P T E R

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The following describes the different possibilities which can be used as root file system. The type of rootfs must be passed as an argument to kernel by means of the bootargs environment variable of U-Boot.

NFSROOT

The rootfs may be in a different computer on the network and not within the target. This can be useful if, for example, a RAM disk is too small to include all the necessary files, or allow rapid turnaround during testing and development.

An NFS root allows quick kernel downloads, helps ensure file system integrity (since the server is basically impervious to crashes by the client), and provides virtually infinite storage.

During development it feel free to use an NFS directory as root file system. This avoids unnecessary flash erases, which on a power failure will result in the need to re-program the kernel into flash. It also increases the lifetime of the module because the flash has a limited number of erase cycles. Initialization scripts may be quickly modified since a failure will not result in an unusable system. Initialization scripts can be fixed on the host then reset the target.

The root file system can be installed to "/exports/BOOTDIR" issuing this command in the project directory

$ make install-nfsroot

To test the new image run the following command at the U-Boot prompt in your target:

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Contents LxNETES User’s Guide ConnectCore 9P 9360/9750 Page Page Page Contents Building the First Project Interfaces & Devices Appendix B Overview IntroductionCross-development environment Template project Linux kernel sourcesExample applications General features FeaturesWhat’s new in LxNETES 3.2? RTC Gpio This is a tip. It contains useful information about a topic Conventions used in this manualAcronyms and abbreviations System Requirements/Prerequisites RequirementsSystem requirements Optional but recommended components Disk spaceTftp daemon Applications & ServicesNFS server JTAG-Booster N E T E S U s e r ’ s G u i d e Getting Started Connecting host PC with development boardIntroduction Seyon MinicomSeyon Settings Connect powerTest Ethernet configuration # ifconfig eth0 Installing LxNETESGuided Installation Manual Installation N u a l Installation Run configure Building the Default ProjectBuilding the First Project Run make Run make installWriting applications Application DevelopmentAdding your own applications Included example applications Using C++Display Proc/cpuinfo contents Debugging applications Choose the right architecture for your target Web server Boa Included pre-built applicationsShell applications busybox Telnet daemon utelnetdEmbedded Qt Nano-X/microwindowsMem Useful applicationsWriting your own kernel modules What is a kernel module?Kernel Development Writing kernel modulesBuilding and loading of kernel modules Add the module to the build environmentIncluded Kernel modules Minimal Advanced Topics Modifying the default projectD i f y i n g t h e d e Fault p r o j e c t Building a custom project Boot Boot processIntroduction Bank # 0 00000000 32 MB ConnectCore 9P 9360/9750NAND-Flash Linux boot methodsUSB NOR FlashMMU Linux boot processV a n c e d T o p i c s Automating the image download Passing arguments to the kernelUpdating the Flash memory Updating a running system manually Updating a running system the easy wayErase the Flash partition Download the new image file to RAMWrite the image to Flash Kernel BootRoot File System Updating a corrupted system using a debugger Root File System Types Download the kernel to RAM via Tftp Set bootargs to be passed to the kernelLaunch the kernel from RAM JFFS2 Copy the kernel to RAM O t F i l e S y s t e m T y p e s N E T E S U s e r ’ s G u i d e Serial interface Interfaces & DevicesLCD interface USB host interfaceI2C interface SPI interfaceReal time clock RTC How to set the initial system date and timeCompact flash interface SD card interfacePCI interface Appendix a CD contentsRelated documentation Docs Images Install.shReadme.txt RelNotes.txtHardware SetupConnectCore 9P 9360 CC9P9360 ConnectCore 9P 9750 CC9P9750Sdram memory layout Memory layoutsFlash memory layout ConnectCore 9P 9360 / ConnectCore 9PTextbase N E T E S U s e r ’ s G u i d e Appendix B Boot command referenceO o t c o m m a n d r e f e r e n c e Skipped CC9C CCXP270 UNC90 Example A9M24x0 User keys