Mill Computing, Inc. Forums The Mill Tools Operating Systems Porting JNode

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  • mkleczek
    Post count: 2
    #959 |


    Did you think about porting a JVM or better yet – pure Java OS to Mill? JNode looks like a good candidate ( ). Probably way easier than LLVM + L4/Linux work. A lot of software available out of the box (sic!).
    It is a little bit unfortunate work to reuse Jikes RVM in JNode was not done (due to licencing incompatibilities) so JNode has its own pure Java JVM implementation.
    Anyway – I would really love to take part in such a project.


  • Ivan Godard
    Post count: 689

    There’s a chicken-and-egg problem with new hardware – you need compilers to write the OS, and you need the OS to run the compilers. The usual route is cross-compilation, and we’re at work on that. For now, OS work – any OS – remains conceptual. And the concept work is very low level, down in the guts of a kernel: how does an interrupt work? How does addressing work? How do you talk to an I/O device? That sort of thing, which must be present for any OS.

    When the LLVM port is up enough to get significant code running (still in sim, of course) then we will make it available and those who, like you, really want to try their own favorite projects on the Mill can do so. We’ll announce it here – but don’t hold your breath, it will take a while yet.

  • mkleczek
    Post count: 2

    Actually this chicken-and-egg problem is the reason why I asked about porting a “pure” Java OS as a means to gain some quick wins at the very beginning.
    JNode has only some bootstrap code written in assembly and it is a JIT/OS combo.
    Porting JNode JIT compiler does not look as difficult as porting GCC or LLVM (especially since there are some architectural difficulties with LLVM).

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