Problem: boot rootfs via nfs

Technical Support
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1

Hello,

i’d like to setup a development system for my target which boot from tftp/nfs.
Additional i want to use static ip’s for target/host to avoid the usage of dhcp.
( nfs is working from userspace/ tftp is working from BL & userspace )

The Problem is that the rootfs is not mounting via nfs during booting. I get errors like this:

[ 17.094919] VFS: Cannot open root device “169.254.10.1:rootfs/” or unknown-block(0,0): error -6

[ 17.105857] Please append a correct “root=” boot option; here are the
available partitions:
…
[ 17.190222] Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(0,0)
… crash & backtrace

setup

A using the binaries from toradex => Apalis_iMX6_LinuxImageV2.6

→ uImage → uImage–3.14.52-r0-apalis-imx6-20160629134804.bin
→ uImage-imx6q-apalis-ixora.dtb → uImage–3.14.52-r0-imx6q-apalis-ixora-20160629134804.dtb

B tftp/nfs dirs are located @ /srv/tftp resp. /srv/nfs/ and the daemons are started.

C move uImage and dtb (as imx6q-apalis-ixora.dtb) in /srv/tftp

D extract & move rootfs in /srv/nfs/rootfs

E using bootloader from previous installation ( via emmc update scripts ):

=> U-Boot 2015.04+fslc+ge1a48b2 (Mar 31 2016 - 01:27:13)

workflow @ BL:

  1. set serverip/ipaddr/netmask

  2. load kernel&dbt via tftp:
    tftp 0x10800000 uImage; tftp 0x12000000 imx6q-apalis-ixora.dtb

  3. adjust bootargs ( tried some settings) :

Kernel command line:
enable_wait_mode=off vmalloc=400M
ip=169.254.10.2:169.254.10.1:169.254.10.1:255.255.0.0:eth0:static
root=169.254.10.1:rootfs/ rw nfsrootdebug fec_mac=00:14:2d:4a:2b:1d
consoleblank=0 no_console_suspend=1 console=tty1 console=ttymxc0,115200n8 video=mxcfb0:dev=ldb

  1. booting: bootm ${kernel_addr_r} - ${fdt_addr_r}

Q: what are the right settings for bootargs in my setup?

Q: i can’t find doc’s/ explanation about bootargs params like “netdevwait”.

Some hints will be helpful.

best regards
Lars

2

Kernel command line has incorrect ip setup it should be:

ip=169.254.10.2:169.254.10.1:169.254.10.1:255.255.0.0::eth0:static

instead of root please use nfsroot and add full host path to the nfs share, in your case

nfsroot=/srv/nfs/rootfs

in case you have problems with NFSv4 you can also try

nfsroot=/srv/nfs/rootfs,vers=3

there is no need to include server’s IP address in nfsroot since you’ve already included it in ip config.

3

Hello and sorry for the late response,

thanks !!! it now boot via nfs/tftp ( update the ip & nfs-vars )

Q: i can’t find doc’s/ explanation about bootargs params like “netdevwait”.

Anyway it is now working. Do you have any hints for me ( for this U-Boot version ).

Best regards
Lars

4

Hi Lars

netdevwait is a remnant of our first Colibri T20 kernel.
All current kernels we use no longer evaluate the parameter.

Regards
Max