I've been using my raspberry pi through Ethernet connection normally. I am powering it through microUSB via my laptop's USB port. Everything was working normally until I installed a new version of gcc by following this guide. After successfully installing gcc I was using my pi normally until I lost connection with my pi.

I tried removing and re-plugging both the Ethernet and the microUSB connectors but nothing is working. When I power up the pi the ACT light flashes for a few seconds and then only the power led stays on. Usually when I plug my Ethernet cable all the other leds flash.

I plugged the SD card into my laptop and it works normally.

I connected my rpi to the monitor, I am getting the following:

[1.153151] ---[end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown block (179, 2) 
[81.6939987]: random: nonblocking pool is initialized

Any help?

  • We can only guess at why you installed a new version of gcc. I don't see a link to the guide you followed. The end result seems to be that you have left the system (on the SD card) in a broken state. You could try the various troubleshooting guides but it sounds like you will have to reinstall the SD card from scratch.
    – joan
    Commented Sep 7, 2015 at 8:19
  • Did you get a solution to your problem?
    – Ingo
    Commented Feb 16, 2018 at 11:19

1 Answer 1


It is likely your problems are power related. A standard USB socket SHOULD deliver 100mA and up to 500mA if negotiated by the device (which the Pi can't do).

Neither is sufficient to reliably power the Pi. Try with a proper power supply.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.