Buildroot external tree for a small footprint Raspberry Pi Zero W image.
build-essential libncurses5-dev rsync cpio python unzip bc wget git
gcc g++ patch file make perl-ExtUtils-MakeMaker perl-Thread-Queue ncurses-devel rsync cpio python3 unzip bc wget git
mkdir raspi-build && cd raspi-build
git clone https://github.com/wasv/raspi-buildroot
git clone --branch 2020.05 https://git.busybox.net/buildroot
make -C buildroot O=../output/ BR2_EXTERNAL=../raspi-buildroot raspi-0w_defconfig # or raspi-3-arm64_defconfig
make -C output clean all # This will take at least 30 minutes, possibly an hour or more.
# The SD Card image will be in output/images/sdcard.img
See the Buildroot User Manual for more instructions.