Commit graph SchOS/docs/licensing.md
Author SHA1 Message Date
Nexoniarz
b08432b2c3 userland: 268 applets, an editor, names that resolve, and a web server
Four complaints, and only one of them was the thing it looked like.

**"toybox is too small."** Half true, and the fix cost no licensing at all:
236 of toybox's applets are what defconfig builds, and the rest live in
toys/pending/ -- awk, bc, diff, more, expr, tr, hexdump, stty among them. Same
0BSD tarball, switched off by a config default. 26 of them are on now, 236 ->
268. Not everything: strace wants ptrace, syslogd wants BSD's facilitynames[],
git wants OpenSSL, and those three break the link.

The toybox build also works again on this machine. Its scripts start
#!/bin/bash, which does not exist on NixOS, so the binary in the tree was one
nobody could reproduce; the shebangs are rewritten to /usr/bin/env bash on the
way in. Pending applets are enabled by editing .config directly, because
`make oldconfig` is the obvious way and undoes it -- every pending symbol is
`default n`.

**BusyBox was asked for and is not here.** It is GPL-2.0-only, and `make
ramroot` links the root image *into the kernel binary*, so it would put GPLv2
inside an Apache-2.0 executable -- which is the exact case ports/Makefile's
NOTPORTS filter and docs/licensing.md §4 exist for. nano is the same answer one
version later. Both recorded in licensing.md with what was done instead, since
"no" without an alternative is how a rule gets quietly broken later.

**An editor that is not vi.** kilo, BSD-2-Clause, one 1300-line file, no
dependencies beyond termios and TIOCGWINSZ, both of which zsh already needed.
Installed as /bin/edit as well as /bin/kilo, because somebody with a file to
fix will type `edit`.

**"wget doesn't work."** Not a userland problem, and BusyBox's wget would have
failed identically: nothing on this system could turn a name into an address,
so every program taking a hostname failed in its own way and each looked like
a separate bug. There is still no DNS client in SchOS and there does not need
to be -- musl has a complete resolver and it works over ordinary UDP sockets.
The one missing fact was which nameserver, which the kernel has had all along
from DHCP and never published. /proc/resolv.conf publishes it in resolv.conf's
exact syntax; cmd/resolvconf decides whether it becomes /etc/resolv.conf, and
will not overwrite a hand-written one without -f.

  # wget -O - http://example.com/ | head -1
  <!doctype html><html lang="en"><head><title>Example Domain</title>

**Something to host with.** cmd/httpd: GET and HEAD, static files, index.html
for a directory and a listing otherwise, a child per connection. No CGI, no
keep-alive, no TLS, no config file. The path check is the only
security-relevant code in it and it refuses rather than normalises -- no
component may be `..`, and percent-decoding happens first, because %2e%2e is
`..` and a check before decoding does not see it. Both forms answer 403.

And the disk is 100 MB, from 32. It is sparse, so the image is 21 MB on the
host. RAMDISK_BLOCKS went 6000 -> 8000 with it: the ramdisk was at 86% and the
next thing added would have broken `make ramroot`, which nobody would have
noticed until they used it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-14 19:24:55 +02:00
Nexoniarz
f38eb8a7fd ldls: L4 was free after all, and the plan closes
L4 was listed as "free -- H2 built all of this" and never actually tested,
which is a claim rather than a result. Tested now, and it holds:

    ldlsd running     ping 2/2; holds index 7 and DMA slots 3 and 4
    killed            interface DOWN, device released, bus mastering
                      cleared, DMA reclaimed -- back to vgpud's 3 blocks
    ping              fails honestly: sendto: -5
    a second ldlsd    ping 3/3, and the arena hands back the same addresses

pciuser_release_all() and netuser_release_all() sit beside each other in
exit() for the same reason, and that they apply unchanged to a foreign driver
is the whole point of having built them against our own.

With that, every milestone on ldls.md is done, so it leaves docs/plan/ for
docs/architecture/ -- the rule docs/plan/README.md states and the one that
keeps the two directories meaning different things. The new document describes
what is, not what was planned: the five rules, the four pieces, what it costs
(polling, no stack protector, locks that are no-ops), that it can be killed,
and a "what it does not do" that leads with one driver, one kernel version,
tried once.

Sixteen source files pointed at docs/plan/ldls.md and would have been dangling
the moment it moved. All repointed, and the milestone references -- which the
architecture doc deliberately does not have -- rewritten to name sections
instead, so a reader lands somewhere real.

The register row closes with it. hybrid.md freed a slot, ldls.md took it, and
it is now free again.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-14 13:37:04 +02:00
Nexoniarz
901ae03a69 ldls: Apache-2.0, and where the boundary actually is
Answers the question directly in docs/licensing.md §6, because "LDLS runs
Linux drivers" reads like it contradicts §2 and does not.

LDLS is Apache-2.0. Every file under ldls/ is ours; the loader came from the
ELF-64 gABI and the x86-64 psABI. The licence of LDLS and the licence status
of what happens at run time are two different questions and only the first is
about us:

  ldls/                       Apache-2.0    distributed by us
  a .ko                       GPL-2.0       distributed by the user's distro
  the two in one process      --            distributed by nobody

GPLv2 §0 says where its obligations attach -- "the act of running the Program
is not restricted" -- so no combined work is distributed by anyone and no
obligation is triggered. Same position FreeBSD has shipped from for a decade.
Stated honestly in the same section: the *user* cannot redistribute the
combination either, which is why RAMDISK_EXCLUDE exists and why .gitignore
refuses *.ko.

EXPORT_SYMBOL_GPL was left open in the plan; it is now answered and the answer
is cleaner than expected. That marking gates *Linux's own* symbols. Every
symbol LDLS provides is ours, reimplemented from facts, so there is no gate
being bypassed because no Linux symbol is being exposed. LDLS implements no
licence check -- it reads the declared licence and prints it before loading
anything.

And the sharpest edge in rule 3 mostly goes away. The uncomfortable row was
struct layouts, which a compiled driver indexes by offset, so the shim must
reproduce them exactly -- and a field-for-field match looks like transcription
even when it is not. It does not have to be in our source: kernels built with
CONFIG_DEBUG_INFO_BTF publish /sys/kernel/btf/vmlinux, and that carries both
the layouts and the function prototypes as generated type data about the
kernel the user already has. Verified on this machine: struct pci_dev field by
field, and FUNC 'pci_iomap' with its FUNC_PROTO. LDLS reads them at load time
on the user's machine; our source contains neither.

That also mostly dissolves rule 4, since BTF describes the kernel that is
actually installed rather than one pinned by guessing. What BTF does not give
is behaviour -- what napi_complete_done *does* is still ours to write from
documentation, and that is the whole of the real work.

Also adds the SPDX header ldls/ko.h was missing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-14 07:52:01 +02:00
Nexoniarz
5263150d3d ldls: the plan for running someone else's drivers
docs/plan/ldls.md. SchOS cannot write a driver for every device that exists
and no project can, so the only route to the hardware support an established
system has is to run Linux's. hybrid.md built the mechanisms for this and said
so; vgpud proved them. This is what they were for.

Five rules, and everything else is an implementation of them:

  1. Nothing GPL ever enters an image we build. The driver is the user's,
     obtained by them, loaded on their machine.
  2. It runs in a process, never in the kernel. Legally a module linked into
     our kernel is the strongest derivative-work argument that exists, and
     practically this is foreign code that must not be able to take the
     machine. FreeBSD has shipped from this position for a decade.
  3. Facts, not expression. A symbol's signature and a struct's offsets are
     facts a compiled driver depends on; comments, macro bodies and inline
     bodies are expression and are never carried over. Provenance recorded per
     file. Flagged in the doc as wanting real legal advice before shipping.
  4. One kernel version at a time, pinned and named, because Linux says in
     writing that it has no stable in-kernel ABI.
  5. The unresolved-symbol list is the specification. Load a real module and
     let the loader say what is missing rather than guessing the surface.

Four pieces: an ELF relocatable loader (ours, clean, no licence question), the
KPI shim (the actual work), /dev/pci as the back end (built), and one new
kernel interface -- a netdev whose backend is a process, which is the exact
analogue of display_ops and is four vtable entries wide.

First target is 8139too rather than r8169, and the reason is decisive: QEMU
emulates rtl8139 and does not emulate r8169, so the obvious choice cannot be
tested at all. 8139too is also smaller, needs no firmware, and uses the thin
mii helpers instead of dragging in phylib. r8169 is what proves it was general,
afterwards and much more cheaply.

The "what it will not do" section carries the honest list, including the two
that are not yet answered: no EXPORT_SYMBOL_GPL story, and no IOMMU -- which
for foreign drivers is a materially worse problem than for our own, and is the
strongest argument for one this project has produced.

hybrid.md is closed and leaves the register; ldls.md takes the slot, which is
the freeze rule working rather than being bent.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-14 01:51:30 +02:00
Nexoniarz
57aff40228 docs: four directories, and a rule for when a thing leaves the roadmap
docs/ was ten files where a plan, a description, a guide and a bug report all
sat next to each other. It is now architecture/ (what SchOS is), plan/ (what it
will be), guides/ (how to work on it) and history/ (why it is like this), with
an index that states the one rule holding it together: when something is
finished it moves from plan/ to architecture/ and is rewritten as a description
of the thing rather than a record of building it.

A ticked checkbox says the work happened. It does not say what the work
*produced*, and six months later the checkbox is all that is left. The network
stack proved the point: finished, verified end to end, and for a month the only
description of it anywhere was a checkbox four levels of indentation deep.

So roadmap.md went from 534 lines to 181 -- nothing deleted, the done work
graduated. Seven subsystems that were finished and undescribed now have
descriptions: boot, kernel, syscalls, filesystem, networking, graphics, usb,
init. Every one ends with "What it does not do", which is the section that pays;
a document listing only strengths is marketing, and the reader who needs it most
is the one about to trip over a limitation nobody wrote down.

schfs.md still opened with "phases 1 through 3 1/2 are done, phase 4 is next"
long after all five had landed. It is a description now, with the phase record
and the hard-won bugs moved to history/.

Three corrections found on the way, all load-bearing:

  * projects/schcom/README.md claimed SCM_RIGHTS was done. There is no
    sendmsg/recvmsg in the kernel at all, and an entire GUI plan rested on it.
  * The root README said "No TCP/IP" months after the stack landed.
  * history/kernel.md sec.7 was marked "in progress" on a problem that process
    groups solved.

Also adds plan/1.0.md, which draws a finish line so the open list stops being
infinite, and marks schwm/ and schde/ superseded: in Wayland the compositor is
the window manager, so that split dissolves rather than being abandoned.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
2026-09-12 17:13:35 +02:00
Nexoniarz
e04ca28812 Rename Schunix to SchOS; the kernel becomes SchIFT
Removes the "-unix" element and with it any trademark exposure to The
Open Group.

The split follows the ecosystem layout: SchOS is the system, and the
kernel has its own name. Kernel-identity strings are the only places
that take SchIFT -- uname(2) sysname, /proc/version, and the two licence
sentences that say "kernel" outright. That is what every Unix does here:
`uname -s` on Linux reports the kernel, not the distribution. Everything
a user reads as the product -- panic screen, boot menu, error prefixes,
docs, LICENSE, NOTICE -- is SchOS.

schunix.img is schos.img, the logo assets and the musl TLS patch are
renamed, and __SCHUNIX__ is __SCHOS__ (the define and the patch that
consumes it moved together).

Two things the rename broke, both found by the bootcheck suite:

  - shmtest wrote "SCHUNIX-MMAP-OK" with a hardcoded length of 15 and
    compared it back by hand-counted offsets (m[3]=='U', m[14]=='K').
    The shorter marker left the write running two bytes past the literal
    and the compare reading past the data, failing a file-backed mmap
    that was working correctly. Now written and compared through one
    constant with sizeof.
  - bootcheck asserted a 31-byte file after appending to
    "hello-from-schunix"; the shorter string makes it 29.

Both are the same mistake: a string literal whose length is written out
somewhere else. Full suite green -- base, Tty, Ps, Sock, Fb, Usb, Evdev.
2026-08-09 14:09:59 +02:00
Nexoniarz
d0f7acf9eb Initial commit: Schunix as it stands before the SchOS rename
An x86-64 operating system built from xv6, now largely rewritten: SMP,
a copy-on-write root filesystem (SchFS), PCI/USB/virtio drivers, a TTF
rasteriser, and a Linux-numbered syscall ABI.

No history before this point -- the tree was never under version control.
This commit exists so the rename that follows has something to undo to.
2026-08-09 13:47:01 +02:00