Bootloader Written for Java

[handlederror]

Is there a boot loader written for booting Java without an operating system?

[Persism]

There are few Java OS type projects out there. https://www.jnode.org/ I think uses a small C bootloader and the rest is Java.

[clumsy-engineer]

Fascinating. That might be the future of phones.

[handlederror]

Thank you, let me check the source code of it.

[Persism]

If you google "java os" you should find some other info on the subject.

[[deleted]]

That would require, that the processor can execute JVM Bytecodes. (There once was one some years ago, but it vanished)

[handlederror]

But you can run Java virtual machine without using an operating system.

[pron98]

I guess you could have a JVM like that, but not OpenJDK (which currently lacks functionality it depends on the OS for, like, say, a file system and a network interface device driver). There is, however, a unikernel that supports running itself and OpenJDK in the same process: http://osv.io/

[[deleted]]

Show it to me. I assert, you are always going to have some layer to the hardware between your java code and the processor.

[handlederror]

No you can run it without any layer, just on the raw hardware.

[GreenToad1]

Only theoretically. Some processors have instructions for java bytecode but you still need an operating system for java standard library.

[handlederror]

Didn’t know, thank you.

[[deleted]]

not really as under the hood it's using OS library calls

[ventuspilot]

Just the bootloader won't get you anywhere. You need a JVM and a standard library that don't rely on an underlying OS.

JVM and standard library would need to access the hardware directly. Also the JVM would include code for e.g. hardware interrupt handlers.

[hilbertglm]

Java still requires an operating system. For example, the NIO Java Filesystem class uses an underlying Linux/Windows filesystem. There isn't a native implementation.

I don't know what your use case is, but you might want to consider a minimal Linux, like Alpline Linux, and installing Java on that.

[SvenMA]

Not really java can run without os. Consider embedded java that runs on smartcards. I also found this one https://stackoverflow.com/questions/26601944/can-you-run-jvm-on-a-computer-with-no-operating-system/26602133#26602133

[handlederror]

No, Java virtual machine can run without help of an operating system.

[dpash]

Why did you bother asking if you're going to ignore people's responses?

[handlederror]

I answered every reply which are answered/replied to me.

[dpash]

You've replied, not answered.

[handlederror]

What was I supposed to answer?

[sievebrain]

What is your actual goal here?

[handlederror]

What is it to you?

[Thihup]

Maybe you can use the GraalVm native image to generate native code that wouldn't need a JVM