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:
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.