Minimal Linux and Buildroot configurations for the Raspberry Pi 3
I was tired to get more than 100 MB of Linux modules by using the bcm2709
Linux kernel defconfig from the Raspberry Pi official Linux repository, so I have created a minimal Linux configuration for the Raspberry Pi 3 and then adapted Buildroot 2018.02-git to get an embedded system with a small footprint.
Result:
wpa_supplicant
and DHCPInstead of making changes directly in Buildroot's tree, I have prepared a simple BR2_EXTERNAL
which can live alongside mainline Buildroot.
Download or clone Buildroot in the parent directory
$ git clone git://git.buildroot.net/buildroot
Create a new directory for the build (to keep the Buildroot tree clean), next to the freshly cloned buildroot
directory
$ mkdir build
To avoid duplicates in the downloaded files, I recommend using a separate directory for the downloads, so create another directory buildroot_dl
$ mkdir buildroot_dl
Select your config
$ cd build
$ make BR2_EXTERNAL=../minimal_raspberrypi_buildroot/ O=$PWD -C ../buildroot/ raspberrypi3_minimal_defconfig
Then make
$ make
After a while, the SD card image is ready in images/sdcard.img
, you can then flash it with dd
or Etcher for example.
quiet
argument given to the kernel, otherwise, the logs through the serial line slow down the boot. And by boot, I only mean the kernel boot, not the userspace (load network drivers then DHCP...)