arm64

So… The RPi 4 has recently been announced. I will be getting one. It has Aarch32 and AArch64. This certainly gives 32-bit RISC OS a stay of execution!

Once RISC OS is ported, it would be cool to have a 64-bit hypervisor that loads RISC OS, if only to allow the possibility of running ‘ARM64’ code from within RISC OS.

I personally think that we will eventually face the same ‘bleak future’ that we did when ARM26 went out of production. However, the 64-bit hypervisor with 32-bit RISC OS could fix that nicely. If such a setup was designed on the RPi 3 and 4 and anything that can run both modes, it would allow the OS to remain 32-bit, and software to start being developed in 64-bit mode (if the coder desires). The OS could be moved to 64-bit over several years, and if 32-bit support is dropped, someone could write a nice dynamic recompiler in ARM64 to keep the OS alive while the remnants are moved to ARM64 (likely via ‘C’ or another slightly higher level language).