git clone https://git.openwrt.org/openwrt/openwrt.git
git checkout openwrt-21.02
wget https://maurerr.github.io/openwrt-21.02-rt305x-4M/config.buildinfo
mv config.buildinfo .config
and then for up2date packages I run these scripts:
./scripts/feeds update -a
./scripts/feeds install -a
It's compiling... hope my computer survives it