On Thu, Sep 20, 2018 at 08:48:37PM +0000, Paul Burton wrote: > > Speaking of nanoMIPS, what is your plan for the syscall ABI there? > > I can see two ways of approaching it: > > > > a) keep all the MIPSisms in the data structures, and just use a subset of > > o32 that drops all the obsolete entry points > > b) start over and stay as close as possible to the generic ABI, using the > > asm-generic versions of both the syscall table and the uapi header > > files instead of the traditional version. > > We've taken option b in our current downstream kernel & that's what I > hope we'll get upstream too. There's no expectation that we'll ever need > to mix pre-nanoMIPS & nanoMIPS ISAs or their associated ABIs across the > kernel/user boundary so it's felt like a great opportunity to clean up & > standardise. > > Getting nanoMIPS/p32 support submitted upstream is on my to-do list, but > there's a bunch of prep work to get in first & of course that to-do list > is forever growing. Hopefully in the next couple of cycles. p32 is just the ABI name for nanoMIPS or yet another MIPS ABI? Either way, І think if there is yet another ABI even on an existing port we should always aim for the asm-generic syscall table indeed. Especially for mips where o32 has a rather awkward ABI only explained by odd decisions more than 20 years ago.
