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docs: README, plan, guides and the site describe what is built now

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README: rewritten around what runs (Linux software, Xorg, apk, Linux's drivers), the honest gaps, measured numbers.
plan/: 1.0.md is the finish line, where each clause of the acceptance test stands, and the register (one failing
clause: a root that survives a reboot); built plans (foundations, hybrid, alpine, xorg) and the decided-against one
(wayland) are gone, their content lives in architecture/; roadmap.md is only what is still open.
guides: building/layout/testing/adding-a-driver (Linux code may be used). history: four entries (ls -lR, TLB
shootdowns, MDIO 0x02460246, netlink MSG_TRUNC). Website: cards, stack, download page, docs index.
Code comments that pointed at deleted plan docs point at the architecture docs.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao
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Nexoniarz 2026-10-26 08:08:05 +01:00
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# What happens next
Everything in this directory is **unbuilt**. When a piece of it is finished it
leaves — deleted from here, rewritten as a description in
[../architecture/](../architecture/). See [the rule](../README.md#the-rule-that-keeps-this-from-rotting).
Everything in this directory is **unbuilt**. When a piece of it is finished it leaves — deleted from here,
rewritten as a description in [../architecture/](../architecture/). See
[the rule](../README.md#the-rule-that-keeps-this-from-rotting).
> ## Read [1.0.md](1.0.md) first.
>
> It draws a finish line and puts most of the work below on the far side of it.
> **Anything not named there is not being worked on**, and the documents in this
> directory describe more than 1.0 contains.
>
> It also holds **[the register of unfinished work](1.0.md#the-freeze-and-the-register-of-unfinished-work)**,
> which is the one place anything half-built is listed. No new capability starts
> until that register is empty, and a row leaves it only by being finished or by
> being deleted from the tree.
> It draws the finish line, says where the system stands against it, and holds
> **[the register of unfinished work](1.0.md#the-freeze-and-the-register-of-unfinished-work)**
> — the one place anything half-built is listed. No new capability starts until that register is
> empty, and a row leaves it only by being finished or by being deleted from the tree.
---
## The three current decisions
Taken together, because they turn out to need the same foundation.
## What is here
| | |
|---|---|
| **[alpine.md](alpine.md)** | **Packages.** The root is managed by Alpine's apk: Alpine's binaries run unmodified, and SchOS itself is the apk package schos-base. |
| **[xorg.md](xorg.md)** | **The desktop.** Xorg on the framebuffer with the fbdev and evdev drivers; twm, then Window Maker. Replaces wayland.md for Gate 3. |
| **[wayland.md](wayland.md)** | *Not being worked on; see xorg.md.* The GUI stack becomes Wayland. SchWM and SchDE are **deleted** — actually gone from the tree, not marked; Schcom survives and changes its wire format. |
| ~~**hybrid.md**~~ | **Built.** All four mechanisms exist, the GPU driver runs outside the kernel, it survives being killed, and the display mode can be changed from a process. H4 (USB) was *withdrawn* rather than left open — USB is the bus peripherals arrive on, not a peripheral. |
| ~~init.md~~ | **Built.** PID 1 is now a role the kernel refills; the description moved to [../architecture/init.md](../architecture/init.md). |
| **[1.0.md](1.0.md)** | **The finish line.** What 1.0 is, the acceptance test and where each clause stands, the register, and everything explicitly deferred. |
| **[roadmap.md](roadmap.md)** | Everything else that is scoped and agreed: storage and the installer, graphics, networking, the hardware that makes a laptop a laptop, SchFS beyond SchOS, the kernel's own gaps. |
| **[gpu.md](gpu.md)** | Linux's own `amdgpu` through LDLS, and the `/dev/dri` a process has to serve. Measured, with the work it needs written down. |
| **[finch.md](finch.md)** | **Later.** The author's own LLVM language for SchOS's applications and tools in place of C. The language is finished and self-hosting in its own repository; the plan here is a target, bindings generated from `include/uapi/`, and the compiler in the image. |
| **[schapi.md](schapi.md)** | The long-term API layering and the compatibility promise. Direction agreed, nothing built. |
And the one they all wait on:
## What used to be here, and is built
| | |
Plans leave this directory when they are done. These did, and what replaced them is the description:
| Was | Now |
|---|---|
| **[foundations.md](foundations.md)** | Descriptor passing, shared memory, sockets in the filesystem. The critical path. **Item 1 is built** — `sendmsg`/`recvmsg` with `SCM_RIGHTS`. |
| Descriptor passing, shared memory, sockets in the filesystem, dynamic linking, the event descriptors (`foundations.md`) | [kernel.md](../architecture/kernel.md), [networking.md](../architecture/networking.md), [syscalls.md](../architecture/syscalls.md) |
| `init.md` | [init.md](../architecture/init.md) |
| `hybrid.md` — drivers in processes, `/dev/pci`, a modeset API, the panic path, why USB stays | [devices.md](../architecture/devices.md) |
| `ldls.md` — Linux drivers in a process | [ldls.md](../architecture/ldls.md) |
| `debugger.md` | [debugging.md](../architecture/debugging.md) |
| `alpine.md` — an apk-managed root | [packages.md](../architecture/packages.md) |
| `xorg.md` — the desktop | [desktop.md](../architecture/desktop.md) |
| The interactive crash screen (`roadmap.md` §4) | GMMOS, in [graphics.md](../architecture/graphics.md) |
And the one that says which parts of the above are actually being worked on:
| | |
|---|---|
| **[1.0.md](1.0.md)** | The finish line. Four gates, and everything else explicitly deferred. |
And the one the hybrid mechanisms were built for:
| | |
|---|---|
| ~~ldls.md~~ | **Built.** The Linux Driver Layer for SchOS: someone else's drivers, in a process, reached through `/dev/pci`. `ping` works over `8139too` and over `e1000`. The description moved to [../architecture/ldls.md](../architecture/ldls.md). |
| ~~debugger.md~~ | **Built**, all of it, including the network transport. A debugger that observes rather than halts and answers in this kernel's own vocabulary: symbols, a log that outlives the kernel, `/dev/dbg`, `whose`, hardware watchpoints, and `schdbgd`. The description moved to [../architecture/debugging.md](../architecture/debugging.md). |
And one for after 1.0, recorded so the decision is not lost:
| | |
|---|---|
| **[finch.md](finch.md)** | **Later.** The author's own LLVM language, Finch, for SchOS's applications and tools in place of C. Already self-hosting; the plan is a target, bindings generated from `include/uapi/`, and the compiler in the image. |
Two longer-horizon documents sit behind these: [schapi.md](schapi.md), the API
layering and the compatibility promise, and [roadmap.md](roadmap.md), which holds
everything still open that is not one of the three above.
And one that was **decided against**: `wayland.md`. Wayland needs DRM/KMS, libinput, udev and libseat, and DRM/KMS
alone is a kernel graphics subsystem. The desktop is X. The reasoning moved to [desktop.md](../architecture/desktop.md).
`SchWM` and `SchDE`, which were to be the window manager and the desktop on top of it, are gone from the tree: Window
Maker is the window manager, and a panel or launcher is an ordinary client.
---
@ -64,86 +49,17 @@ everything still open that is not one of the three above.
Set by [1.0.md](1.0.md), which is the authority. In short:
### 0. Fix what is already wrong — **first**
Not a document of its own; it is Gate 0 of [1.0.md](1.0.md), assembled from the
*What it does not do* sections in [../architecture/](../architecture/).
**Before any new capability**, and the reason is the one that put
`netdev_selftest()` before the TCP/IP stack: a compositor built on a kernel with
an unexplained hang and a socket layer that reports success for things it did not
do will fail in ways indistinguishable from its own bugs.
### 1. `foundations.md` — the critical path
Both the Wayland work and the hybrid work stop here. Descriptor passing and
shared memory are the substrate for handing a buffer to a compositor *and* for
handing a device to a driver process. **Doing it once for both is the entire
reason these are one plan rather than three.**
### 2. `init.md` — before the desktop, not after — **done**
A compositor being brought up for the first time crashes constantly, and
something that restarts it and says why is worth far more during that work than
at the end of it. Built; see [../architecture/init.md](../architecture/init.md).
### 3. `hybrid.md` — **moved up, and the reason is worth recording**
This document used to put the hybrid work *after 1.0*, deliberately last, on this
argument:
> designing a userspace driver interface with no driver consuming it produces an
> interface that is wrong in ways nobody can see
The argument was sound and the conclusion drawn from it was wrong. What forced
the change was the driver situation: SchOS cannot write a driver for every device
that exists, no project can, and the only route to the hardware support an
established OS has is a compatibility layer with the foreign drivers kept
*outside* the kernel. That layer is this plan's mechanisms. It is not optional and
it is not late work.
The original argument still holds, and it is answered rather than ignored:
**SchOS's own drivers are the consumers.** `vgpud` is a real driver, with real
requirements, and building the interface against it is what keeps it a general
mechanism rather than a hole shaped like something foreign. The compositor is
still a demanding consumer — it is no longer the *only* one available.
Four mechanisms, all built. One eviction done, the second withdrawn with its
reasons recorded, and the foreign driver host they were for is
[../architecture/ldls.md](../architecture/ldls.md) — built, and carrying
packets.
### 4. `wayland.md` — with the GPU driver either side of the seam
W1–W3 and a terminal. W4 and W5 are post-1.0. Item 1 of `foundations.md` —
descriptor passing — was the thing it could not start without, and it now
exists.
---
## In one sentence
> Fix what is broken, build the descriptor-passing and shared-memory substrate,
> make init survivable, move the drivers out through an interface SchOS's own
> drivers have to live with first — and put a terminal on the screen.
---
1. **Close the one open gate**: decide what makes a root survive a reboot — the installer, or a narrower
definition of 1.0 (see *The one open decision* there).
2. **Empty the register.** Delete `projects/schcom/` and the unused in-kernel LDLS window, or say what they are for; build
socket activation or remove the key.
3. **Then**, and only then, whatever [roadmap.md](roadmap.md) says is next. GPU acceleration is the thing the laptop
wants most ([gpu.md](gpu.md)), and Finch inside SchOS is the thing the author wants next ([finch.md](finch.md)).
## What this plan does not address
Stated here so it is not mistaken for covered:
- **No IOMMU**, so the hybrid work isolates against bugs and not against a
hostile driver.
- **No page cache**, so `foundations.md` delivers a `memfd` and not a general
answer to shared file mappings. The general answer is still owed.
- **No garbage collector for descriptors in flight**, so an `AF_UNIX` socket
passed over itself and never received leaks. Bounded at thirty-two sockets, and
nothing on this plan does it.
- **No dynamic linking**, so no Mesa, no accelerated clients, and no third party
shipping a `.so` for anything.
- **A new compatibility surface** between PID 1 and PID 2, created by a plan
whose own [schapi.md](schapi.md) §3 spends a section warning about those.
- **The three open networking items** — `getsockname`, routing, and
interrupt-driven receive — are untouched by any of this and still open. They
are in [roadmap.md](roadmap.md).
- **No IOMMU**, so a driver in a process is isolated against its own bugs and not against a hostile driver.
- **No page cache**, so a general writable `MAP_SHARED` of a file is refused; `memfd` is the narrow answer.
- **No installer**, so nothing a live system writes survives a reboot.