Thank you for reviewing!
2016-03-19 15:37 GMT+09:00 Rich Felker <dalias(a)libc.org>:
Looks very good! Some comments:
In regards to your schedule, do you plan to do both rv32 and rv64 (and
some 'subarch' ABI variants for both) in parallel from the beginning?
I think it might make sense to get one (whatever is easiest) to the
point where you can do some meaningful testing before working on them
all, but I'd be happy to hear your thoughts on what approach works
best for you.
Yes, I planed to port 32-bit and 64-bit variant in parallel. However,
now I think that porting one first and then doing the other is better
since this approach can test the toolchain part earlier.
One thing to keep in mind (not sure if you're aware of it yet) is
there's an in-progress port, now linked from the lowrisc.org
ideas page, by another student who's interested in applying. Please
don't be discouraged by that; the reason I'm mentioning it is just
that I think anyone applying should either be planning to use the work
that's already done (being careful to properly document authorship) or
have a good explanation for why they're not going to. For your
proposal, this probably means greatly reducing the number of weeks to
be spent on getting the port basically up and running and dedicating
more time to the extended deliverables.
I didn't aware of that port. Thanks!
I will take a look at it and revise the proposal with my decision.
That's actually a good thing because I don't think you've
much time for the extended deliverables as they might take. For
example, for the vdso stuff, if you plan to do the actual kernel
patches, that's going to require familiarizing yourself with kernel
hacking if you're not already. And hooking it up to GCC for the
compiler to use with -mno-atomic (rather than just having libc use it
internally) requires some GCC hacking _and_ establishing some ABI for
the GCC-generated code to get to the vdso (probably via libc).
Sure. I will reconsider the schedule.
Hope these comments help, and sorry for not getting back to you
sooner. I've had a busy week.
No problem. This really helps me.