I am getting booting issue while porting linux image(zImage) on my raspberrypi2 board. The infrastructure in doing so are:


  1. Raspberry Pi 2 board
  2. USB to Serial converter


  1. Ubuntu 14.04 LTS on host system
  2. Buildroot_2015_11_1

For the configuration of buildroot I followed the instructions described in the buildroot link below: https://git.busybox.net/buildroot/tree/board/raspberrypi/readme.txtbuildroot configuration process

After generating the image I flashed my SD card(16 GB) with the generated images and binaries in boot partition and root file system in root partition. (My boot partition is 60 MB (FAT32).

My cmdline.txt content is

sdhci-bcm2708.sync_after_dma=0 dwc_otg.lpm_enable=0 
root=/dev/mmcblk0p2 rootwait

I even changed it to

elevator=deadline rootwait 

in order to make it work but that even did not work (I mean RPI not booting). In my config.txt, the kernel assignment was kernel=zImage (even then RPI not booting) I even changed it to kernel=u-boot.bin and the problem still exists.

Note: I am using putty or minicom both but unable to see the booting sequence.

I have also tried the way the paper of Mariano Ruiz describes about buildroot configuration but still the problem remains the same.

Please let me know how to proceed in such scenario.

2 Answers 2


Okay, so finally I am getting the log in prompt. I found one configuration missing in buildroot. Under system configuration I enabled following: 1. Enable root log in and password. 2. Run a getty (login prompt)after boot. 3. remount root-filesystem read-write during boot.

After the above configuration I did Make. After flashing the images to the SD card the boot messages started and stopped at non-blocking pool. Then I pressed Enter and the login got activated.

  • Please accept your own answer with a click on the tick on its left side. Only this will finish the question and it will not pop up again year for year.
    – Ingo
    Dec 20, 2019 at 23:51

With a default build, boot messages appear on a screen connected to the HDMI. /etc/inittab does not have an entry for ttyAMA0,so no getty will run. The image that comes out of build root is very basic,unless specially sshd, and the like were selected at build time and also configured to start at boot time. If you have connected ethernet to your router, it should obtain an address.

Connect a monitor through HDMI and keyboard to the device and login. After that add an entry to the inittab to start a getty on ttyAMA0.

What happens when the enter key is pressed at the "nonblocking pool is initialized"

  • But .etc/inittab comes into picture when init is started which happens only after the u-boot sequence. At least I should be getting the u-boot sequence messages before, the init. Dec 16, 2015 at 5:04
  • Okay now I am seeing the booting sequence coming after connecting the HDMI. But another problem I am seeing that there is no log in prompt coming so that even I can log in as root. Please suggest me what is the possible reason for this? Dec 26, 2015 at 13:42
  • To make the above comment more clear, the booting sequence is getting stuck at "random: nonblocking pool is initialised". If I am adding "init=/bin/bash" in the cmdline.txt I am getting kernel panic. Please suggest me the solution for this. Dec 28, 2015 at 7:24

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