2

I'm attempting to get a minimal buildroot system up and running on my Raspberry Pi 3 B+ but after I've flashed the SD card, installed the card, powered up the pi, and connect an HDMI cable, I only ever get the multicolor screen with the lightning bolt.

From what I understand, I should be getting a getty prompt with the ability to login. I've followed the instructions on the buildroot GitHub page: https://github.com/buildroot/buildroot/tree/master/board/raspberrypi but with no avail. I run the following commands to build the image:

make raspberrypi3_64_defconfig

make

The result of my build contains the following files/directories:

cm2710-rpi-3-b.dtb 
bcm2710-rpi-cm3.dtb
boot.vfat
rootfs.ext2  
rootfs.ext4
rpi-firmware 
sdcard.img 
zImage

I then flash the card with sudo dd bs=4M status=progress if=sdcard.img of=/dev/sdb

I don't see any options explicitly for the raspberry pi 3 b+, I just assumed the raspberrypi3_64_defconfig was the correct configuration.

Getting to a login screen will be a huge win for me! Thanks.

  • do you know what the "lightning bolt" means? usually means you don't have a good power supply – Jaromanda X Jan 19 at 3:05
  • @JaromandaX yes I am aware. What's interesting is I have successfully booted several other OSs with the same exact hardware setup. This makes me believe that I have done something wrong with building the image. Maybe old firmware? Not sure. – user985030 Jan 19 at 3:15
  • oh ... that is interesting, not sure I can help then – Jaromanda X Jan 19 at 3:24
  • Which model Rpi do you have? Your text says B+ and your tag says 3B+. And what exact command did you use? The readme lists specific commands for each board. – T. M. Jan 19 at 14:36
  • @T.M. Sorry, I left off the 3. I have the RPI 3 B+ with ARM v8 A53 arch. – user985030 Jan 20 at 14:21
2

raspberrypi3_64_defconfig isn't even listed in the readme, I assume because it's experimental. Try

make raspberrypi3_defconfig

That's the one listed so it should be expected to work.

2

I figured out what my issue was. For some reason, the version of build root I pulled down didn't contain the proper files for the Pi 3 B+. These are the steps that I followed:

  1. git clone https://github.com/buildroot/buildroot.git
  2. cd buildroot
  3. make raspberrypi3_defconfig
  4. make
  5. dd bs=4M status=progress if=./output/images/sdcard.img of=/dev/sdb

I then put the card in and it booted like a champ. Now I can spend time configuring my OS with what I actually need! Yay!

To be clear, the file that I couldn't find when was this one: bcm2710-rpi-3-b-plus.dtb. That was definitely the magic sauce that caused me to fail previously. Thanks @T.M. for pointing this out to me.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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