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| -rw-r--r-- | host/docs/usrp_e3x0.dox | 70 |
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diff --git a/host/docs/usrp_e3x0.dox b/host/docs/usrp_e3x0.dox index e23bbaeb5..ac9687f4f 100644 --- a/host/docs/usrp_e3x0.dox +++ b/host/docs/usrp_e3x0.dox @@ -739,6 +739,76 @@ Example device address string representation for 2 USRPs with IPv4 addresses **1 addr0=192.168.10.2, addr1=192.168.20.2 +\subsection e3xx_nfs_root Booting from a NFS root + +Booting your device from a NFS root might be desirable for remote deployment, management or similar applications. + +Requirements: + +- NFS server (for configuration see your Linux distribution's documentation) +- dtc (devicetree compiler) +- Filesystem image + +\subsubsection e3xx_nfs_root_extract Extracting the filesystems + +The first step to make a root filesystem available via NFS is to extract the root file system. +This can be done as follows: + + $ sfdisk -l -uS <your-image>.direct + +Which should produce output similar to: + + Disk release3-image.direct: 7 GiB, 7516197888 bytes, 14680074 sectors + Units: sectors of 1 * 512 = 512 bytes + Sector size (logical/physical): 512 bytes / 512 bytes + I/O size (minimum/optimal): 512 bytes / 512 bytes + Disklabel type: dos + Disk identifier: 0x8bc3587b + + Device Boot Start End Sectors Size Id Type + release3-image.direct1 * 8 36871 36864 18M c W95 FAT32 (LBA) + release3-image.direct2 36872 14680071 14643200 7G 83 Linux + +From this one can see the second partition (root filesystem) starts at sector *36872*, +and has a length of *14680071*. We can use the *dd* tool to extract the root filesystem +into a handy file. + + $ dd if=<yourimage>.direct of=<yourimage_rootfs>.direct offset=36872 count=14643200 + +The same procedure can be done for the boot partition. + + $ dd if=<yourimage>.direct of=<yourimage_boot>.direct offset=8 count=36864 + +Both of these files are mountable on your NFS server, e.g. by: + + $ mount <yourimage_rootfs>.direct /srv/nfs/root-e3xx + $ mount <yourimage_rootfs>.direct /srv/nfs/root-e3xx/media/FAT + +Copy the uImage, uEnv.txt, u-boot.img, boot.bin from the extracted boot partition to the +boot partition of your device's card. + +Use the devicetree compiler to modify e300-devicetree.dtb file as follows: + + $ dtc -I dtb -O dts e300-devicetree.dtb -o e300-devicetree.dts + +Using your editor of choice modify the *chosen* property in e300-devicetree.dts from: + + console=ttyPS0,115200 root=/dev/mmc0blkp2 rw rootwait earlyprintk + +to: + + console=ttyPS0,115200 root=/dev/nfs rw nfsroot=<yourserverip>:<yourpath>,vers=3 rootwait ip=dhcp earlyprintk + +Use the devicetree compiler to compile the modified devicetree as follows: + + $ dtc e300-devicetree.dts -o e300-devicetree.dtb + +Copy the modified *e300-devicetree.dtb* to your device's card. + +For more information on server configuration please refer to your Linux distribution's NFS Server manual, +for more information about NFS root see the +<a href=https://www.kernel.org/doc/Documentation/filesystems/nfs/nfsroot.txt>Linux Kernel NFS Root documentation</a> + \section e3x0_comm_problems Communication Problems When setting up a development machine for the first time, |