How to run process from kernel

[tomsk]

So what should I do?

[dseller]

The code for your executable resides at the end of your kernel. Because that’s where you placed it.

Not even that.

The code for that executable is appended after a proper ELF file. qemu has a built-in bootloader that knows how to read ELF files, so it will look at the ELF headers and load what those headers state. It will not see the second ELF file, as there is no entry for that - its just garbage at the end.

There is also no way to tell a linker you are going to append blobs later - after all, that requires a file offset outside of the initial file which is illegal.

Yeah, that's what I meant to say. I guess "after" would have been a better word choice.

So what should I do?

This is pretty basic stuff. My honest advice for you is to go and learn the fundamentals of system programming.

[tomsk]

So if it is so easy you could show me solution of it

[iansjack]

If you are going to combine the "process" with your kernel, just do it at the source code stage. Define it as another function that you call from main().

[tomsk]

But function is not a process, process is application.

[iansjack]

Not the way that you are trying to do it. You are trying to build it as part of the kernel and then call it. What makes that any different from a simple function?

OK. You need to implement a file system and an elf loader. Then you can load the application from storage at the appropriate address and then run it.

[tomsk]

So without file system it is not possible? That it would load into memory at specific address?

[iansjack]

I'm not convinced that you really know what you want to do.

What makes a process, or application, any different from a function in your kernel?

[glauxosdever]

Hi,


In order to be able to run a process, you need to get some code and data in a separate user-space address space. How you will get this code and data is another matter.

But I'm getting the impression you are putting the cart before the horse. Start with the kernel core, i.e. interrupt handling, memory management and in-kernel thread management and scheduling. Then try to do user-space processes.


Regards,
glauxosdever

[Combuster]

So if it is so easy you could show me solution of it

Was I supposed to repeat my second post here?