Support for ARM9

[leo60228]

This means that, at the moment, Hubris won't run on your Game Boy Advance, Nintendo DS, or Apple Newton.

The DS has an MPU, so it's further along than the docs make it sound... I doubt anyone has a burning desire to actually use hubris on a DS, though.

[cbiffle]

The DS likely has an MMU, so we'd need to generate pagetables etc. to use it like an M-series MPU.

[mx-shift]

AFAIK Nintendo DS has an ARM946E-S and an ARM7TDMI both w/o MMU.

…

On Fri, Jan 21, 2022, 4:37 PM Cliff L. Biffle ***@***.***> wrote: The DS likely has an *MMU,* so we'd need to generate pagetables etc. to use it like an M-series MPU. — Reply to this email directly, view it on GitHub <#370 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACIEHF6TT7ZPEIQIK45BKQDUXH36JANCNFSM5MH2IJYQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.*** com>

[cbiffle]

That was my understanding as well, but I've never developed for the DS. If that's the case, Hubris is definitely not the right platform.

[leo60228]

The ARM7TDMI is identical to the GBA's which has neither an MMU or MPU, but I believe the DS's ARM946E-S has an MPU with no MMU (see gbatek).

[cbiffle]

Funky! I've never seen one of those on an ARM9 core before. That looks very similar to the MPU later standardized in the M/R architecture profiles, though only at a conceptual level -- it's accessed rather differently and has some register layout differences, if I'm reading this correctly.

You might be able to get that working. To manage expectations, we are unlikely to accept such changes upstream -- we don't use ARM9 cores and I'm pretty sure my DS needs a new battery. :-)