I've set up my own package repository and have published a .deb package to it using reprepo. The code was cross-compiled for Raspberry Pi4 on an Ubuntu x86-64 machine using CMake and CPack. That much works. But it doesn't work on a PiW and fails with an
Illegal instruction, as expected.
When I look in
/etc/apt/sources.list the sources listed appear to be the same for a PiW and a Pi4,
deb http://raspbian.raspberrypi.org/raspbian/ buster main contrib non-free rpi
So how do I create my own .deb packages that work on both PiW and Pi3/4?