commit e26522ab0db3c5f71fe4ac1337d41f67e72e5cc9
parent 5752ef1179d4f8ecebbb6cbb4c377c9dfbebc556
Author: Virgil Dupras <hsoft@hardcoded.net>
Date: Mon, 29 May 2023 19:57:43 -0400
Update README to reduce duplicate with website contents
Diffstat:
| M | README.md | | | 202 | ++----------------------------------------------------------------------------- |
1 file changed, 3 insertions(+), 199 deletions(-)
diff --git a/README.md b/README.md
@@ -13,190 +13,8 @@ Dusk OS innovates by having an ["almost C" compiler][duskcc] allowing it to
piggy-back on UNIX C code, through a modest [porting effort][port], to reach
its goals and stay true to its design constraints with a minimal effort.
-[Video showcasing Dusk OS][demovideo]
-
-## Why build this OS?
-
-Most modern operating systems can do whatever we want them to do. Why do we
-need another one? Simplicity.
-
-It's difficult to predict post-collapse conditions, but we can suppose that many
-users will need to use their machines in novel and creative ways. Hackability
-of the operating system then becomes paramount. Open source modern operating
-systems all can be modified to fit its user's needs, but their complexity limits
-the likelihood that the user is able to do so. A simpler OS increases this
-likelihood.
-
-But we can't have our cake and eat it too, right? Either you have a simple toy
-OS or a complex one. Well, maybe not?
-
-Its authors believe that in the history of computing, Forth has been
-under-explored. Its approach to simplicity is, we think, revolutionary. It
-has significant shortcomings when system specifications become more complex
-(Forth hates complexity and doesn't manage it well), but we believe it
-possible to elegantly marry it with languages that like complexity better.
-
-This mix, we believe, could provide a [creative][creative] user with computing
-powers rarely seen with other approaches. We've got to try it.
-
-To be clear: this is a research project, we don't know what it will yield
-beforehand. We have the intuition that it might lead to a big "ah ah!" moment
-and reveal a breathtaking combination of power and simplicity.
-
-## Features making Dusk OS special
-
-### A whole OS built from source on boot
-
-One thing that makes Dusk OS special is that it boots from a very tiny core
-(1000 lines of i386 assembly). From this tiny core, on boot, it builds its way
-up to a system that has a functional C compiler, which then allows it to
-bootstrap itself some more.
-
-With regards to "source bootstrapping", it's even more extreme than Collapse OS
-because modern machines allows this process to run quickly and the whole
-process is still faster than a regular Linux boot. On Collapse OS target
-machines, this process would be prohibitive, so a bigger part of the OS is
-cross-compiled into the kernel.
-
-This peculiarity of Dusk OS has interesting properties. The nicest one, in my
-humble opinion, is that this allows us to sidestep the *entire* problems of
-binary compatibility and relocation and only deal with source compatibility.
-So, no ELF, no binutils, only code that is designed to run from where it was
-generated in the first place. This is so much simpler!
-
-Object files? Global symbols? Nah. C functions that don't have a static storage
-type are simple Forth words.
-
-### Harmonized Assembly Layer
-
-Dusk features what we call the [Harmonized Assembly Layer][hal] (HAL for short).
-This is a cross-CPU assembler, on which the C compiler relies, which prioritizes
-implementation and usage simplicity, but is also designed to generate efficient
-native code.
-
-### Shortest path to self-hosting for an "almost C" compiler
-
-Dusk OS self-hosts in about 800 lines of assembly and a few hundred lines of
-Forth (the exact number depends on the target machine). From there, it
-bootstraps to DuskCC, which is roughly 2000 lines of Forth code (including
-arch-specific assemblers). To my knowledge, Dusk OS is unique in that regard.
-
-You can pick any C compiler that requires POSIX and it will automatically
-require order of magnitudes more lines of code to bootstrap because you need
-that POSIX system in addition to the C compiler. So even if you pick a small C
-compiler such as tcc, you still need a POSIX system to build it, which is
-usually in the millions of LOCs.
-
-To be fair, Dusk OS is not the first project thinking of optimizing that path.
-[Efforts at making our modern software world bootstrappable][livebootstrap]
-lead to an "almost C", [M2-Planet][m2planet] with a feature set comparable to
-DuskCC with very few lines of code. M2-Planet itself is about 5K lines of code
-and the various stages that lead to it are generally a few hundred lines each.
-The project initially ran on top of regular kernels (as in "fat kernels with
-lots of code"), but some bare metal stages ([1][builder-hex0],
-[2][stage0-uefi]) were created and now this little chain end up being
-comparable to Dusk in terms of lines of code. Still more than Dusk, but in the
-same ballpark.
-
-Although this path is short and technically leads you to an "almost C"
-compiler, you can hardly use it because it has no "real kernel" (those bare
-metal stages mentioned above are enough to compile M2-Planet, but really not
-much else, they're extremely limited) and no shell. You'll need those if you
-want to use your shiny compiler.
-
-One of your best picks, should you try this path, would be [Fiwix][fiwix], a
-minimal POSIX i386 kernel weighting less than 50K lines of C+asm. But then,
-M2-Planet is not enough. You need to compile tcc (which M2-Planet can compile
-after having applied a few patches) which weights 80K. Userspace is worse.
-Bash+coreutils are 400K, even busybox is 190K. We still end up with a pretty
-minimal and simple system, but it's still a lot more code than Dusk.
-
-So, unless someone tells me about some option I don't know about, DuskCC is
-quite innovative on the aspect of self-hosting path length.
-
-## Who is Dusk for?
-
-The target Dusk user is someone who's [creative][creative], close to hardware,
-can read a datasheet. Dusk shines (well, *will* shine) when one wants to poke
-around the hardware without limit.
-
-It compares favorably to other more complete OSes because there's no concurrent
-process to mess with your poking and the driver structure is (well, *will*
-hopefully be) more approachable, hackable due to its stricter scope and savvier
-target audience.
-
-Let's use an example. Let's say you're on a notebook that runs on a chipset of
-Intel's ICHn family. You read the datasheet and see "oh, nice, there's an SPI
-interface in there. Maybe that it's not hooked to anything on the notebook,
-let's play with it."
-
-Now, that chipset is very, very central to the computer. There are good chances,
-on a BSD or Linux system, that if you begin poking around its registers, you'll
-step on someone else toes and crash the system because, for example, of some
-other process that needed to read from disk at the same time.
-
-In Dusk, you could completely break the SATA controller, you'll still be golden
-as long as you don't access mass storage. Because Dusk doesn't have
-concurrency, you have tight control over what happen or doesn't happen on the
-machine, so all you need to do is to avoid words that access mass storage. That
-gives you ample wiggling space for your hacking session.
-
-To be clear: this is also possible with a custom made BSD or Linux, but you're
-going to have to strip a lot of pieces from your distro before you get there
-and some of those pieces might be useful debugging tools which will be
-difficult to retrofit because they need a wider system. You'll also need a
-higher cognitive space to fit BSD/Linux wider abstractions in your mind.
-
-## Status
-
-* Has a VM written in C, buildable from a POSIX environment, which allows Dusk
- to build itself for any of its supported targets.
-* Has an ["almost C" compiler][duskcc] which still needs some work, but is
- already capable of compiling a nice subset of C.
-* It can run bare metal on some PCs (and QEMU, of course). It has drivers (in
- various state of sophistication) for:
- * VGA in text mode
- * PS/2 keyboard
- * PCI controllers
- * ATA controllers
- * AHCI controllers
- * Floppy controllers
- * PC COM ports
- * VESA in graphical mode
- * PS/2 mouse support
-* Can read, write and boot from FAT12/FAT16 (no FAT32 for now) volumes.
-* Can create new FAT12 volumes.
-* Very small footprint. In Grid mode (TUI mode) with the Grid text editor
- and DuskCC (including its stdlib) loaded, Dusk uses 180KB of RAM on a PC.
-* It completely self-hosts on all its target (only PC for now) machines.
-* Simple and terse. The core system (all kernels, drivers, filesystems, CC,
- core libraries) is less than 8K lines of code.
-* Since `text/ed` has reached a usable status, the main author of Dusk has been
- developing it from within itself on an old Pentium 75 Mhz with 16mb of RAM and
- he's having a blast.
-
-List of ported codebases:
-
-* The CVM of [Collapse OS][collapseos]
-* The [uxn][uxn] VM
-* The `puff()` algorithm from [zlib][zlib]
-* The [left][left] text editor. (Still a bit glitchy...)
-
-List of homegrown applications:
-
-* C Compiler (see `doc/cc`)
-* Text editor (see `doc/text/ed`)
-
-What's next? See the [roadmap][roadmap]!
-
-Development happens on [sourcehut][shproj].
-
-Unlike Collapse OS which is a personal effort and doesn't lend itself well to
-collaboration, Dusk OS' wider scope makes it fitting for a collective effort.
-Let's discuss this on its [public mailing list][mailinglist].
-
-It's also worth noting that I've started a blog, [Tumble Forth][tumbleforth]
-that offers hand-holding into the wonderful world of Dusk OS and Forth.
+This is Dusk OS' source code and the rest of the README assumes that you want to
+run it. To read more about why this OS exists, see its [website][website].
## Build and run Dusk
@@ -262,6 +80,7 @@ Press Escape to return to prompt. You can try the same thing with:
* `tests/manual/uxn/mouse.fs`
* `text/left.fs`
+[website]: http://duskos.org
[collapseos]: http://collapseos.org
[coswhy]: http://collapseos.org/why.html
[creative]: http://collapseos.org/why.html#creative
@@ -271,19 +90,4 @@ Press Escape to return to prompt. You can try the same thing with:
[port]: fs/doc/design/port.txt
[shell]: fs/doc/design/shell.txt
[docs]: fs/doc/index.txt
-[roadmap]: ROADMAP.md
-[shproj]: https://sr.ht/~vdupras/duskos
-[mailinglist]: https://sr.ht/~vdupras/duskos/lists
-[duskcc]: fs/doc/cc/index.txt
-[hal]: fs/doc/hal.txt
-[livebootstrap]: https://github.com/fosslinux/live-bootstrap
-[m2planet]: https://git.sr.ht/~oriansj/M2-Planet
-[builder-hex0]: https://github.com/ironmeld/builder-hex0
-[stage0-uefi]: https://git.stikonas.eu/andrius/stage0-uefi
-[fiwix]: https://www.fiwix.org
-[uxn]: https://wiki.xxiivv.com/site/uxn.html
[varvara]: https://wiki.xxiivv.com/site/varvara.html
-[zlib]: https://github.com/madler/zlib
-[left]: https://git.sr.ht/~rabbits/left
-[demovideo]: https://vimeo.com/800710912
-[tumbleforth]: https://tumbleforth.hardcoded.net/
