I have available: Pentium M (standard i586), Intel Atom (old eye PC), modern AMD Ryzen (I don't remember the model number, but it has 6 cores), Beaglebone Black (one core Arm32 Cortex A8), Orange Pi PC+ (Allwinner H3, 4 Cortex A7 cores), Raspberry Pi 3 model B+ (aarch64), Raspberry Pi 4 (aarch64), and soon a single-board PC with risc-v Allwinner D1 will arrive.
These are the platforms on which I plan to implement ReMinix.
Sorry for the English - I'm too lazy to think, I'm writing through Google Translate.
I have many plans, but they all require, first and foremost, major changes to the kernel and virtual memory manager. I'm currently working on this.
Seriously, within a month I'll release a kernel with full Arm32 support. I'm immediately separating everything into layers, so the architecture-dependent code will remain only in the kernel HAL. So it will be as easily portable as possible across different OS platforms.
Current progress: I've written a complete hal for the Orange Pi PC+ and am currently finishing up the smp. A little later, I'll finish the new ipc for the virtual memory manager, then rework it.
And then, with peace of mind, I'll work on the new service and driver hierarchy. I've already sketched out a bit about USB, but there's a lot to do.
Basically, I'm out of work in my country. If I don't starve to death or they don't completely block our internet access, I'll finish this by summer. =)
I've been working with embedded systems on Linux and Android my whole life, as well as low-level development. I've written many Linux drivers for proprietary projects for my clients and employers. But an entire OS is a truly new challenge, even though I read Tanenbaum's books as a teenager.