The given link is an opam repository that contains a description of the
forked compiler for easy installation via opam. Looking at the description
file for the compiler


https://github.com/nojb/riscv-ocamlopt/blob/master/compilers/4.02.0/4.02.0%2Briscv64-unknown-elf/4.02.0%2Briscv64-unknown-elf.comp

it appears that the upstream source (currently) is a branch of the
github:nojb/ocaml repository:

  https://github.com/nojb/ocaml/commits/4.02.0%2Briscv64-unknown-elf

On Sat, Sep 10, 2016 at 12:41 PM, Richard W.M. Jones <rich@annexia.org>
wrote:

> (Resurrecting the old thread ...)
>
> On Sun, Jun 07, 2015 at 11:14:16PM +0530, Nicolas Ojeda Bar wrote:
> > This release is in the form of a cross-compiler.  It depends on the
> > cross-compiling support recently added to 4.02.0+trunk.  It outputs
> > ELF binaries that can be simulated directly on the RISC-V ISA
> > simulator (spike) or run natively in a suitable virtual machine.
> >
> > For detailed installation instructions, please visit:
> > https://github.com/nojb/riscv-ocamlopt.
>
> Hi Nicolas,
>
> I'm confused here -- where is the upstream source?  For example, is
> there a fork of the upstream OCaml git repo with your changes on top?
>
> Rich.
>
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