[Libre-soc-dev] Litex-OPENTitan clarification

[Cole Poirier]

On Sun, Sep 27, 2020 at 9:32 AM Cole Poirier <colepoirier at gmail.com> wrote:
>
> On Fri, Sep 25, 2020 at 1:48 PM Luke Kenneth Casson Leighton
> <lkcl at lkcl.net> wrote:
> > On 9/25/20, Cole Poirier <colepoirier at gmail.com> wrote:
> > > I took a look at OPENTitan and it is a silicon root of trust.
> >
> > buzzwords. ignore them.
>
> Ah, makes sense, thanks.

I took a proper look through it today, and indeed ignoring the
buzzwords allows a much better understanding of the project.

> > > I don't
> > > understand how we would be able to translate that into nmigen and use it to
> > > replace litex. Can you explain this to me?
> >
> > look more closely at the code.  it is templated autogenerator
> > basically exactly like litex except systemverilog and exclusive to
> > RISCV processors.
> >
> > codegeneration is done by json files instead of python functions.
>
> Hmmmm :) Very cool!

Even cooler now that I've had a proper look through the project files
and the structure. *Idea* since Jacob and I don't have a lot of HDL
work to do while you work very closely with Staf and JP this month, I
was thinking that it might be a fantastic opportunity to create the
nmigen version of OPENTitan that you said you'd prefer to use instead
of litex (obviously not for use on the 2 DEC tapeout but for a
subsequent tape-out in 2021). There's a SystemVerilog IEEE compliant
parser library in rust, so I was thinking I could work with Jacob on
creating a tool that uses this to convert the parts we want from
OPENTitan into our litex-replacement nmigen implementation. I suggest
creating a sv2nmigen translator because doing this any other way than
automated/auto-generated would be massively time-consuming (the
project is >100K LOC). Ideally, Jacob and I would work on this largely
without 'bothering' you, as I wouldn't want to distract you from the
priority of our 30 OCT code-freeze deadline. Also, this is assuming
that Jacob is even interested in working on this... Brain still a tad
melty so pardon the style of this email, but I think this is possibly
a good idea... let me know what you think :)

Cole