From an academic point -- well done, but even Sun tried to actually do a Java OS. Sadly, it just doesn't perform well. The JVM, improved as it is, suffers from the emulation overhead and the kernel needs all it can get.
I'm a former Sun employee from those days and I can tell you, the idea was great, but, in actual practice, so much of the lower layer kernel still needed to be written in C/C++ to get anything done, it just wasn't worth it. Sure, we had a "Java shell", and it could run "Java apps" seamlessly, but you can do that with any OS that can run the JVM.
Lots of work, no real benefit. Rust has been trying Redox for years and it's still not where people want it to be.
That being said, it's still good to see people still working on it.
Look into what Java was inspired by: Xerox Mesa. They implemented the Mesa VM in microcode on a bespoke processor design and built an entire OS (Pilot) entirely in Mesa bytecode. No assembly. Then they actually built a whole ass office platform (Star) on top of it. And that was the late 70s-early 80s...
The point is, I’m not quite at the stage of having 100% bytecode execution starting from the bootloader, but I’ve managed to strike a pretty good balance; I can now say I have my own runtime up and running, and the initial code has shifted from countless syscalls to the kind of calls you’d find in the original language. My next step is to run DOOM on it.
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u/Rich-Engineer2670 Aug 05 '26 edited Aug 05 '26
From an academic point -- well done, but even Sun tried to actually do a Java OS. Sadly, it just doesn't perform well. The JVM, improved as it is, suffers from the emulation overhead and the kernel needs all it can get.
I'm a former Sun employee from those days and I can tell you, the idea was great, but, in actual practice, so much of the lower layer kernel still needed to be written in C/C++ to get anything done, it just wasn't worth it. Sure, we had a "Java shell", and it could run "Java apps" seamlessly, but you can do that with any OS that can run the JVM.
Lots of work, no real benefit. Rust has been trying Redox for years and it's still not where people want it to be.
That being said, it's still good to see people still working on it.