>"anti-open source CPU cores" I take it you're talking about the SoC rather than the CPU. In this case, open-source drivers for ARM SoC weren't exactly common

>"anti-open source CPU cores" I take it you're talking about the SoC rather than the CPU. In this case, open-source drivers for ARM SoC weren't exactly common when the RPi was launched. For example, I can't think of a single open-source GPU driver (used with ARM SoCs) that was available at the time.