4 ms·
I was under the impression you could get away with using Machine mode for both the SBI and the Kernel? Sv39 paging is the major requirement as you point out.
by p0llard 7y ago
I was under the impression you could get away with using Machine mode for both the SBI and the Kernel?
Sv39 paging is the major requirement as you point out.
- Taniwha 7y agoMachine mode runs without the MMU, linux really needs an MMU to do kernel stuff too (including stuff like copyin/copyout)
- p0llard 7y agoAh, I didn't actually know this, thanks for pointing it out :)
- nickik 7y agoThere is actually quite a bit of work going on in Linux without MMU. Check Linux Plummers conference RISC-V track for example.
- Taniwha 7y agoYeah that's why I said "really needs", there are cut down versions that will run without an MMU, it's not really the mainline Linux though - I've worked with MMUless kernels in the past, it's not a lot of fun (and I started porting V6/V7 for base and bounds swapping machines)