d73985633b
Shift is the logo, Guru is the icon, SchCotie is the mascot, and the difference
between them is not stylistic. An icon works once, at one size, in one state. A
mascot has to be able to *do* things -- confused, pleased, asleep, seen from
behind -- which is why it costs more and is drawn last. Written down because
this is exactly the kind of decision that gets re-derived badly.
Assets/ becomes docs/branding/, which also fixes two things:
* Filenames had spaces in them, so every reference needed quoting. They are
lowercase and hyphenated now.
* Assets/ held hand-written SVG and generated PNG in one directory, which is
the one rule docs/guides/layout.md states.
The guide records what was previously only in people's heads:
* The constraint everything answers to -- include/logo.h is a 128x128
single-channel coverage mask, so a mark has to survive as a solid shape in
one colour and be recognisable at 24 px. Colour is the last decision, never
the first.
* Guru's purple is load-bearing. PSOGM_BG #4B1D9A is deliberately not the
accent #7C5CFF, and theme.h's rule is that the full-bleed purple belongs
entirely to failure. If Guru appears in accent violet on a sticker, the deep
purple stops meaning "the machine stopped" -- and it is the only colour in
the system that means anything.
* Why shift-mask.svg is a separate file from shift.svg. mklogo.py reads ink as
(255 - luminance) * alpha, so tones survive as coverage and the relationship
inverts: darkest here is brightest on screen. Copying the violet fills would
light the object from below.
* Why a raster is committed beside its SVG. inkscape is not a build
prerequisite, so requiring a vector rasteriser would break the build on most
hosts for a file that changes about once a year.
* That the BSD daemon is copyrighted and SchCotie must be drawn from the
concept rather than from Beastie. A daemon is a Greek daimon and a Unix
background process; neither is ownable. The pitchfork, the sneakers and that
face are.
Format rule: SVG, or PNG at high resolution with no lossy compression, nothing
else. SVG is the source of truth for every mark and a raster is generated from
it, never edited.
include/logo.h regenerates byte-identical from the new path -- only the source
comment differs. The two old wordmark SVGs were deleted outside this session and
are left deleted; their PNGs are kept as superseded-*.png for reference.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
137 lines
6.2 KiB
Markdown
137 lines
6.2 KiB
Markdown
# SchOS documentation
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Four kinds of document, kept in four directories, because they answer four
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different questions and go stale at four different rates.
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| **[architecture/](architecture/)** | *What SchOS is* | Present tense. Describes what is built and working. |
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| **[plan/](plan/)** | *What SchOS will be* | Future tense. Everything here is unbuilt. |
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| **[guides/](guides/)** | *How to work on it* | Imperative. Build it, test it, add to it. |
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| **[history/](history/)** | *Why it is the way it is* | Past tense. Bugs whose cause is not visible from the fix. |
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Plus two that belong to no category and apply to everything:
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**[licensing.md](licensing.md)** — read it before copying anyone else's code in —
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and **[branding/](branding/)**, which holds the marks and the rules for using
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them.
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---
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## The rule that keeps this from rotting
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> **When something is finished, it moves from `plan/` to `architecture/` and is
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> rewritten as a description of the thing rather than a record of building it.**
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A completed item is not a ticked checkbox. A ticked checkbox says the work
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happened; it does not say what the work *produced*, and six months later the
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checkbox is the only thing left and it explains nothing.
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So finishing a piece of work has three steps, and the third is not optional:
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1. The code works and is tested.
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2. The plan entry is deleted.
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3. A description exists in `architecture/` written for somebody who was not
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there — what it does, what shape it has, what it costs, and what it still
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does not do.
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This is not bookkeeping. The tree has already proved it necessary: the network
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stack was finished, verified end to end, and for a month afterwards the only
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description of it anywhere was a checkbox in a roadmap, four levels of
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indentation deep, written in the past tense of somebody arguing for the work
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rather than explaining the result.
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**The "what it does not do" section is the one that pays.** Every description in
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`architecture/` ends with one. A document that only lists a subsystem's
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strengths is marketing, and the reader who most needs the document is the one
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about to trip over a limitation nobody wrote down.
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---
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## Start here
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**New to the tree** → [architecture/README.md](architecture/README.md), the
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system layer by layer, then [guides/layout.md](guides/layout.md) for where the
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files are.
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**Trying to build it** → [guides/building.md](guides/building.md).
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**Wondering what happens next** → [plan/1.0.md](plan/1.0.md), which is the finish line, then [plan/README.md](plan/README.md) for the order.
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**Something is broken and it feels familiar** → [history/](history/). There is a
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good chance it is in there.
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---
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## architecture/ — what SchOS is
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| [README](architecture/README.md) | The system, layer by layer. Read first. |
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| [boot.md](architecture/boot.md) | Firmware to the first userspace process. |
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| [kernel.md](architecture/kernel.md) | SchIFT: memory, processes, scheduling, traps, signals, SMP. |
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| [syscalls.md](architecture/syscalls.md) | The call table, and the Linux personality that lets real software run. |
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| [filesystem.md](architecture/filesystem.md) | The VFS, the buffer cache, procfs, mounts. |
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| [schfs.md](architecture/schfs.md) | SchFS: the copy-on-write root filesystem. |
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| [devices.md](architecture/devices.md) | The device model, driver binding, the class vtables. |
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| [usb.md](architecture/usb.md) | xHCI, the USB core, and the class drivers. |
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| [graphics.md](architecture/graphics.md) | Framebuffer, text rendering, console, and the crash screen. |
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| [networking.md](architecture/networking.md) | Drivers, lwIP, sockets — Unix and INET. |
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| [init.md](architecture/init.md) | `schinit`, PID 1, and the job manifests. |
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## plan/ — what SchOS will be
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| [README](plan/README.md) | The three current decisions and the order they happen in. |
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| [1.0.md](plan/1.0.md) | **The finish line.** What 1.0 contains, and what is explicitly deferred past it. |
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| [foundations.md](plan/foundations.md) | The kernel work everything else is blocked on. |
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| [init.md](plan/init.md) | PID 1 becomes a role rather than a process. |
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| [wayland.md](plan/wayland.md) | The GUI stack, and what gets deleted to make room. |
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| [hybrid.md](plan/hybrid.md) | Moving drivers out of the kernel. |
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| [schapi.md](plan/schapi.md) | The long-term API layering, and the compatibility promise. |
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| [roadmap.md](plan/roadmap.md) | Everything else still open. |
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## guides/ — how to work on it
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| [building.md](guides/building.md) | Prerequisites and the build, per host. |
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| [testing.md](guides/testing.md) | The harnesses, and what each one actually proves. |
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| [layout.md](guides/layout.md) | Repository map, and how to add a program or a port. |
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| [adding-a-driver.md](guides/adding-a-driver.md) | Writing one, binding it, publishing its class vtable. |
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## branding/ — the marks
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| [README](branding/README.md) | Shift the logo, Guru the icon, SchCotie the mascot: what each is for, the colour rule, and why a raster is committed next to its SVG. |
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## history/ — why it is the way it is
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| [README](history/README.md) | What belongs in here and what does not. |
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| [kernel.md](history/kernel.md) | Bugs whose cause was nowhere near their symptom. |
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| [moving-to-linux.md](history/moving-to-linux.md) | The Windows-to-Fedora move, kept for the parts that recur. |
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---
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## Writing one of these
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Four conventions, all of them observable in the existing files:
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**State the cost.** Every design choice gave something up. A document that does
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not say what is a document that will be argued with later by somebody who only
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sees the downside.
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**Prefer the measured number to the remembered one.** "500 of 3565 files carry
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the advertising clause" is worth more than "some do", and it was worth the
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minute it took to count.
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**Write down the bug that shaped it.** Half the non-obvious code in this tree is
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non-obvious because something failed once. If a design is strange, the strangeness
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is load-bearing and the reader deserves to know why before changing it.
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**No dates in headings.** A date in a heading turns a description into a
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changelog, and the description is the thing with a long life. Dates belong in
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`history/`, where they mean something.
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