Re: Introducing a nanoMIPS port for Linux

From: Arnd Bergmann
Date: Fri May 04 2018 - 19:53:11 EST


On Fri, May 4, 2018 at 9:24 AM, James Hogan <jhogan@xxxxxxxxxx> wrote:
> On Thu, May 03, 2018 at 06:40:07PM -0400, Arnd Bergmann wrote:
>> On Wed, May 2, 2018 at 5:51 PM, James Hogan <jhogan@xxxxxxxxxx> wrote:
>>
>> While I haven't looked at the individual changes, I wonder whether
>> it would be useful to make this new ABI use 64-bit time_t from
>> the start, using the new system calls that Deepa and I have been
>> posting recently.
>
> Personally I'm all for squeezing as much API cleanup in as possible
> before its merged, though obviously there'll be a point when the ABI may
> need to be frozen, at which point we'll mostly have to accept what we
> have within reason.
>
>> There are still a few things to be worked out:
>> only the first of four sets of syscall patches is merged so far,
>> and we have a couple of areas that will require further ABI changes
>> (sound, sockets, media and maybe a couple of smaller drivers),
>> so it depends on the overall timing. If you would otherwise merge
>> the patches quickly, then it may be better to just follow the existing
>> 32-bit architectures and add the 64-bit entry points when we do it
>> for everyone.
>
> I think it'll likely be a couple of cycles before it gets merged anyway.
> There's still work to do, and limited resources.

Ok, let's plan on getting the 64-bit time_t ABIs in place early enough
then. We will likely have very similar timing for the upcoming rv32
ABI on arch/riscv.

Arnd