OS as a Virtual Machine

[kmasruiz]

Hello all,

I've designed an OS which is based on a Microkernel architecture and initially it will run on a x86 bochs machine. I have the functional analysis, but currently (I guess all new OS developers also) I don't know how to start.

Yes, I've readed the Getting Started (http://wiki.osdev.org/Getting_Started) and the Bare Bones tutorial (http://wiki.osdev.org/Bare_Bones). I'm not asking for development help at all, but for technical design tips. Recommendations from other programmers who successfully started an OS development project. I'm going to resume my project fastly:

In a simplistic point of view I want a LISP compiler written in C. That LISP "dialect" would be an "assembler language" in a LISP manner, a very low-level language. Having this, I would implement a macro system for generating LISP code (as Common LISP or Scheme does). The C compiler will evaluate that macros and generate the low-level LISP code, and then, compile it in x86 machine code.

The OS shell must:

1. Eval and compile LISP code.
2. Have access to the filesystem (I would like to implement a simple one, and rewrite it in a future).

I don't want yet access to Internet, nor GUI nor audio. I only want a shell.

I repeat myself again: I don't want help in the development at all. I want tips for designing the project, how to face the technical analysis.

Thank you all for reading and thanks for the OSDev Wiki.

PS: I moved myself the thread to the appropiate category.
PS2: If anyone wants/needs more information, feel free to ask in this thread.

[Brendan]

Hi,

Draw a diagram consisting of one box with "OS" written inside that box. Now, repeatedly follow these steps:

• For each box that has no children:
  • If that box can be completed then complete it and remove the box from your diagram
  • If that box can't be completed, then:
    • Determine how to split the work into several smaller pieces of work (e.g. "OS" might need to be spit into "micro-kernel", "LISP compiler", "Drivers" and "Applications")
    • If any of those smaller pieces are already in your diagram, draw a line from current box to the existing child
    • Put the remaining smaller pieces of work into the diagram as new child boxes

Note: Don't limit the diagram to pieces of software that need to be implemented (e.g. don't be afraid to create boxes like "Research possible virtual memory management techniques" if that's work you need to do).

This basically describes "top down design, bottom up implementation" using a dynamically changing tree. Initially you'll be drawing lots of boxes; eventually the first thing you complete will probably be a boot loader; and one day you might end up with an empty tree/diagram.


Cheers,

Brendan

[Love4Boobies]

You may find the book recommandations on the wiki useful.

PS: Since your OS will be LISP-based, it would be pretty cool for your shell to be a Lisp REPL.

[kmasruiz]

Thank you for your replies.

I'll draw that tree, I hope it will help me across the development. That was a lot of help, I need a clear development path.

Yeah I want the shell to be a LISP REPL with a debugger. But maybe it's to complex at this moment. I'm going to implement the deugger later. hanks!