| Filename | Latest commit message | Latest commit date |
|---|---|---|
c4d4f20548
PSOGM drew ":(" -- two dots and a parenthesis. It now draws Guru, the icon from
docs/branding/: a chamfered head with two eye knockouts and a flat mouth, in the
:| register.
The old reasoning is kept in the file rather than deleted, because it is the
thing being traded away: ":(" was "legible as a mood without being a picture of
anything, and does not pretend the machine has feelings about what just
happened." That is a real argument and a face is a louder claim. What it buys is
identity -- ":(" is recognisably Microsoft's, and a crash screen is the single
screenshot most likely to leave the machine, so it is the worst place to be
wearing somebody else's face. The octagon also quotes the chamfered corners of
the old SchOS letterforms, which is the only part of that mark still in use.
Still drawn from primitives, for the original reason: it scales with the display
and costs no space in the kernel image. A scanline fill for the head, two
rectangles and one more knocked out of it -- no allocation, no locks, nothing
that can fail halfway, which is the whole constraint of panic context. The
geometry is expressed in the same 200-unit box docs/branding/guru.svg uses so
the two cannot drift without somebody editing a number on purpose.
The eyes and mouth are knocked out of the head rather than drawn on top of it,
which is what keeps them legible small: a hole in a solid reads at sizes a
stroke does not.
Verified by crashing on purpose -- echo c > /proc/sysrq -- and screendumping the
framebuffer through the QEMU monitor. The serial report still says ":(", and
should: Guru cannot be drawn in ASCII, and a mood marker in a log is not the
icon.
Separately, and found by looking at the boot splash rather than at the code:
boot/common/ui.c includes logo.h, theme.h and font.h, and the Makefile rule for
the loader listed none of them. A new logo therefore did not rebuild the loader.
The splash had been drawing a mask compiled six hours earlier while `make`
reported nothing to do, and the only symptom was a boot screen quietly
disagreeing with the kernel about what the logo is. The kernel half never showed
it because those objects are built with -MD -MP and track their own headers.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
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| .. | ||
| architecture | ||
| branding | ||
| guides | ||
| history | ||
| plan | ||
| licensing.md | ||
| README.md | ||
SchOS documentation
Four kinds of document, kept in four directories, because they answer four different questions and go stale at four different rates.
| architecture/ | What SchOS is | Present tense. Describes what is built and working. |
| plan/ | What SchOS will be | Future tense. Everything here is unbuilt. |
| guides/ | How to work on it | Imperative. Build it, test it, add to it. |
| history/ | Why it is the way it is | Past tense. Bugs whose cause is not visible from the fix. |
Plus two that belong to no category and apply to everything: licensing.md — read it before copying anyone else's code in — and branding/, which holds the marks and the rules for using them.
The rule that keeps this from rotting
When something is finished, it moves from
plan/toarchitecture/and is rewritten as a description of the thing rather than a record of building it.
A completed item is not a ticked checkbox. A ticked checkbox says the work happened; it does not say what the work produced, and six months later the checkbox is the only thing left and it explains nothing.
So finishing a piece of work has three steps, and the third is not optional:
- The code works and is tested.
- The plan entry is deleted.
- A description exists in
architecture/written for somebody who was not there — what it does, what shape it has, what it costs, and what it still does not do.
This is not bookkeeping. The tree has already proved it necessary: the network stack was finished, verified end to end, and for a month afterwards the only description of it anywhere was a checkbox in a roadmap, four levels of indentation deep, written in the past tense of somebody arguing for the work rather than explaining the result.
The "what it does not do" section is the one that pays. Every description in
architecture/ ends with one. A document that only lists a subsystem's
strengths is marketing, and the reader who most needs the document is the one
about to trip over a limitation nobody wrote down.
Start here
New to the tree → architecture/README.md, the system layer by layer, then guides/layout.md for where the files are.
Trying to build it → guides/building.md.
Wondering what happens next → plan/1.0.md, which is the finish line, then plan/README.md for the order.
Something is broken and it feels familiar → history/. There is a good chance it is in there.
architecture/ — what SchOS is
| README | The system, layer by layer. Read first. |
| boot.md | Firmware to the first userspace process. |
| kernel.md | SchIFT: memory, processes, scheduling, traps, signals, SMP. |
| syscalls.md | The call table, and the Linux personality that lets real software run. |
| filesystem.md | The VFS, the buffer cache, procfs, mounts. |
| schfs.md | SchFS: the copy-on-write root filesystem. |
| devices.md | The device model, driver binding, the class vtables. |
| usb.md | xHCI, the USB core, and the class drivers. |
| graphics.md | Framebuffer, text rendering, console, and the crash screen. |
| networking.md | Drivers, lwIP, sockets — Unix and INET. |
| init.md | schinit, PID 1, and the job manifests. |
plan/ — what SchOS will be
| README | The three current decisions and the order they happen in. |
| 1.0.md | The finish line. What 1.0 contains, and what is explicitly deferred past it. |
| foundations.md | The kernel work everything else is blocked on. |
| init.md | PID 1 becomes a role rather than a process. |
| wayland.md | The GUI stack, and what gets deleted to make room. |
| hybrid.md | Moving drivers out of the kernel. |
| schapi.md | The long-term API layering, and the compatibility promise. |
| roadmap.md | Everything else still open. |
guides/ — how to work on it
| building.md | Prerequisites and the build, per host. |
| testing.md | The harnesses, and what each one actually proves. |
| layout.md | Repository map, and how to add a program or a port. |
| adding-a-driver.md | Writing one, binding it, publishing its class vtable. |
branding/ — the marks
| README | 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. |
history/ — why it is the way it is
| README | What belongs in here and what does not. |
| kernel.md | Bugs whose cause was nowhere near their symptom. |
| moving-to-linux.md | The Windows-to-Fedora move, kept for the parts that recur. |
Writing one of these
Four conventions, all of them observable in the existing files:
State the cost. Every design choice gave something up. A document that does not say what is a document that will be argued with later by somebody who only sees the downside.
Prefer the measured number to the remembered one. "500 of 3565 files carry the advertising clause" is worth more than "some do", and it was worth the minute it took to count.
Write down the bug that shaped it. Half the non-obvious code in this tree is non-obvious because something failed once. If a design is strange, the strangeness is load-bearing and the reader deserves to know why before changing it.
No dates in headings. A date in a heading turns a description into a
changelog, and the description is the thing with a long life. Dates belong in
history/, where they mean something.