Buster ArmHF Cross Compile
From embeddedTS Manuals
Buster and probably newer Debians have simplified the cross compiler setup significantly.
To prepare the system for ARM cross-compiling, add the armhf cross-architecture to host Debian system:
sudo dpkg --add-architecture armhf
sudo apt-get update
sudo apt-get install build-essential libncurses-dev libncursesw5-dev bc
From this point the host system is set up and ready to compile binaries for most ARMHF platforms.