and renamed it "Core words". Also, reworded the presentation.

More portable

Instead of letting each configuration taking care of RDLN$ and
"CollapseOS" prompt, move this to BOOT to simplify xcomp units.

Initialization source code is now only for driver initialization.

During "make updatebootstrap", we use less than 0x20 bytes on the
PSP side and less than 0x40 bytes on the RSP one. 0x100 bytes ought
to be enough for anybody.

Finally got rid of the XPACKed core and managed to cross-compile
all core words, which greatly simplifies the bootstrapping process.

Makes xcomp.fs units shorter.

TODO: implement X['] so that I can remove those XCURRENT patterns.

This leaves space for xcomp-core which is growing.

This allows us to move words like ABORT" to xcomp-core, which is
I think the last roadblock before being able to unify all drivers
into a single xcomp layer.

No more low/high

Now I struggle to remember why I ever did things they way I did.
There must have been a reason...

Not yet tried on real hardware, but we should be getting pretty
close...

There's a bug where the first char after a-lock isn't a-modded. I
have troubles figuring it out for now. It feels like deja vu. I
think I had the same problem with asm.

Pushed all words directly interfacing with ports and memory offsets to
low level layers. This saves us the need for keeping those variables in
runtime memory.

The goal is to insert device drivers in between.

In emulator of course...

On the emulator of course...

Gave more priority to CPU in the emulator because initialization would
otherwise be horrendously slow.

I implement the screen using XCB which is much more friendly
than z80e's SDL+CMake for development machines that want to install
minimal dependencies (for example, a port-less OpenBSD rig).

This allows us to get rid of the zasm.sh wrapper.

Also, increase STDIO_BUFSIZE to 0x40 so that those while loops work.

That's my mega-commit you've all been waiting for.

The code for the shell share more routines with userspace apps than with kernel
units, because, well, its behavior is that of a userspace app, not a device
driver.

This created a weird situation with libraries and jump tables. Some routine
belonging to the `kernel/` directory felt weird there.

And then comes `apps/basic`, which will likely share even more code with the
shell. I was seeing myself creating huge jump tables to reuse code from the
shell. It didn't feel right.

Moreover, we'll probably want basic-like apps to optionnally replace the shell.

So here I am with this huge change in the project structure. I didn't test all
recipes on hardware yet, I will do later. I might have broken some...

But now, the structure feels better and the line between what belongs to
`kernel` and what belongs to `apps` feels clearer.

Most of register fiddling routines (which is now the only thing contained
in care.asm) are used by almost all userspace apps, often in inner loops.

That makes the penalty of using jump tables for those a bit too high.
Moreover, it burdens jump tables needlessly.

Because this unit is very small (now that string routines are out), it makes
sense to always include it in binaries.

And made them shorter in name. The new ascii.h file allow reuse in userspace
code.

ref #41

This allow a lot more characters to fit on that tiny screen...

ref #41

ref #41

ref #41

For now, only digits are scanned. Lifted from my "tiseg7" example.

ref #41

There's no scrolling yet...

ref #41

ref #41

This was mostly lifted from my "tihello" example, but it required significant
adjustments.

This commit also introduces a font management system. A lot of fonts are
available online, but sources aren't always clear so to avoid copyright
landmines, I re-created my first 5x7 font from scratch.

As it is now, this resulting ROM gets "Collapse OS>" to be displayed on the
LCD screen. Much work still left to do.

ref #41