The first thing you have to do is make sure you have a recent Qemu
installation. It has to be enough recent to support multiboot
kernels. Just installing the version of your distribution should
work. Now, get the source code from the repository
git clone https://github.com/davazp/eulex.git
Move to the directory where it was cloned and type
compile. In order to launch QEmu with the Eulex image, run the script
./run-eulex.sh. If you pass any argument to this script, they are
passed to QEmu. It can be useful to enable sound, for example.
At this point, the system should boot as below. You can type Forth
code right there and it will be evaluated. Indeed, you can type TAB
key to autocomplete words, or use some emacs-like keybindings, e.g:
By default, the context provides standard Forth words, but if you want
to hack the internals you will need access to the internal
vocabulary. Use the word
eulex to do that. You can try to type
words to list all the words in a context. In the internal
vocabulary, there are about a thousand words.
It is possible to disassemble words, e.g:
see edit-line. Note that
the disassembler uses the current context to look call addresses back
into word names. If many addresses are not showing, try moving to the
There is not persistent storage, after halting QEmu, or rebooting with
reboot, changes will be lost. Therefore, you could want
to write code in the file
eulexrc.fs, which is loaded automatically
when the system starts.
In closing, I would like to include a couple of nice pictures. The
first one is an incomplete screen block editor,
The second one is a little Lisp interpreter, written in Forth.
I hope you liked it. If you fancy hacking this and enjoy it as I did,
do not hesitate to write to me, I will help you with pleasure. There
many minor details, if you would like to try it but no to spend so
much time. If you feel adventurous, then the points to work are:
Rewriting forth.S as a crosscompiler to run on GForth, the 100% of the
code would be Forth. The system could compile itself eventually. The
assembler I wrote can be used to this task, as it executes both in
Eulex as in GForth.
It is as native as described in this document. Code is very
inefficient. We could optimize it, but we do not want if the compiler
is written in assembler. So bootstraping should come first.
- Hard disk driver and FAT implementation.
Actually, files are stored built-in with the same Eulex image, so they
- Dumping and restoring the world
When the floppy driver or a file system implementation is working,
dumping the dictionary to the disk would have the nice effect ot
saving the whole state of the system.