After testing the waters with a Linux for Jaguar port; I basically set myself to get similar results on the 32X add-on for the Sega Genesis. Turns out that, even without hardware synchronization primitives, you can get smp-ready Linux: https://github.com/cakehonolulu/linux_ports
This is exciting! I didn’t see anything about I/O, but could the serial port be used for terminal access (or to drive keyboard input for the console). Lots of untapped potential.
With the Sega CD you’d get more RAM and a second, faster 68k
Hi! I'm basically forwarding UART data from the SH2s over to the M68K using a simple communication channel. Since the SH2s don't really have "direct" access to the Genesis's I/O port (They have TTL UART which caps at 4800 bps) I need this precise schema to have output. Technically speaking it should be simple enough to wire RXD too so you can interact with it. I saw some keyboard prototypes for the Genesis online (Which seem to use the Joypad ports) but I figured no one would have them so why bother writing a driver for it (Which again, would add more complexity to the M68K dispatcher; which does UART and acts as an INTC "master" to forwards IPIs between the 2 SH2s).
As to the Sega CD; it'd probably be cool but this is already super-slow as it is (There's lots of bus contention already from 2 x SH2s and 1 x 68000) so yeah.
Maybe a cool project would be SMP for the 2 68000s (Sega CD + Genesis) but I'm not even sure if there's any form of SMP available for arch/m68k in Linux (If both 68000s are wired you could maybe get away-ish with some simple bringup but can't really say for sure).
Thank you very much! Is the SSFv2 mapper supporting memory writes in the MiSTer FPGA, too? (Megadrive and/or 32x cores). Also, now that there's a SH3 core already available ([1] for replicating the Cave CV1000 system), it could be mind blowing having a system with 512MB of RAM on a SH3 at 100MHz running Linux.
[1] https://github.com/ika-musume/HS3