licence: SchOS is GPL-2.0-or-later, no longer Apache-2.0

Nexoniarz is the sole author and SchOS was never published under
Apache-2.0, so this is a straight relicence. LICENSE is the FSF GPLv2 text,
every first-party SPDX header moves to GPL-2.0-or-later, and NOTICE,
README.md, docs/licensing.md and the site say so. projects/schfs-linux
follows the rest of the tree.

The GPL gives copyleft: a fork has to ship its source. It also lifts the
old "Linux drivers, never" rule, since GPL-2.0-only code combines with
GPL-2.0-or-later. "Or later" leaves room for GPLv3, but one binary still
has to pick one version, so docs/licensing.md now keeps Apache-2.0 and
GPLv3 code out of the kernel to keep Linux code possible there. BSD
4-clause code goes from "avoid" to "no", because the advertising clause
is GPL-incompatible.

LDLS still ships no .ko. That boundary is now project policy rather than
a legal requirement, and ldls.md, devices.md and licensing.md section 6
say so. refmod declares license=GPL, and ldls-check passes (27 checks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ports/Makefile

@@ -1,6 +1,6 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # SchOS ports — third-party software, one directory per port.
-# All ports are permissive-licensed (MIT, BSD, 0BSD, Apache 2.0).
+# Every port's licence must combine with GPL-2.0-or-later; see docs/licensing.md.
 #
 #   ports/musl/    libc — installs headers/libs to build/ports/musl/prefix
 #   ports/mksh/    MirBSD Korn Shell — installed as sysroot/bin/sh
@@ -17,7 +17,7 @@
 
 # Ports that live in this directory but are deliberately not built by `make`.
 # Empty for now; the filter stays because the reason it existed will recur --
-# a port whose licence cannot be combined with Apache-2.0 can be kept here for
+# a port whose licence cannot be combined with GPL-2.0-or-later can be kept here for
 # local testing but must never be built into a SchOS image.
 NOTPORTS :=
 PORTS := $(filter-out $(NOTPORTS), \

ports/fastfetch/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # fastfetch -- system information, MIT: https://github.com/fastfetch-cli/fastfetch
 #
 # Here because it is a good acceptance test, not because SchOS needs a fetch

ports/kilo/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # kilo — BSD-2-Clause: https://github.com/antirez/kilo
 #
 # SchOS's text editor, installed as sysroot/bin/kilo with `edit` beside it.
@@ -11,9 +11,9 @@
 #
 # The whole editor is one 1,300-line C file with no dependencies beyond libc --
 # termios and TIOCGWINSZ, both of which SchOS already has because zsh needs
-# them. That is the entire reason it was chosen over nano: nano is GPLv3 and
-# wants ncurses at runtime, and GPLv3 cannot be combined with Apache-2.0 any
-# more than GPLv2 can. See ../../docs/licensing.md.
+# them. That, and licensing at the time, is why it was chosen over nano: nano
+# is GPLv3 and wants ncurses at runtime, and SchOS was then Apache-2.0. Under
+# GPL-2.0-or-later nano is possible, but kilo already does the job.
 #
 # What it does not do: no undo, no multiple buffers, no configuration, no
 # mouse, no UTF-8 beyond passing bytes through. It edits one file.

ports/lwip/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # lwIP — the TCP/IP stack. BSD-3-clause (no advertising clause); see COPYING in
 # the tarball and docs/licensing.md.
 #

ports/mk/port.mk

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # Shared definitions for all SchOS ports.
 # Include this at the top of each port's Makefile:  include ../mk/port.mk
 #

ports/mksh/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # mksh (MirBSD Korn Shell) — permissive: https://www.mirbsd.org/mksh.htm
 # Installed as /bin/sh — SchOS standardizes on "sh" as the one shell name;
 # no ksh/dash/other aliases are installed or looked up by init.

ports/musl/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # musl libc — MIT-licensed: https://musl.libc.org/
 #
 # Installs into $(PREFIX) (= build/ports/musl/prefix), which port.mk exports

ports/ncurses/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # ncurses -- terminal capability database and screen library, MIT:
 # https://invisible-island.net/ncurses/
 #

ports/ncurses/tinfotest.c

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: Apache-2.0
+/* SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ncurses acceptance test for SchOS.
  *

ports/toybox/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # toybox — 0BSD-licensed: https://landley.net/toybox/
 # Provides SchOS's core utilities (ls, cat, cp, mv, rm, mkdir, ...) as a
 # single multicall binary, installed under sysroot/bin/ once per applet name.

ports/zsh/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: Apache-2.0
+# SPDX-License-Identifier: GPL-2.0-or-later
 # zsh -- the Z shell, MIT-like: https://www.zsh.org/
 #
 # Installed as /bin/zsh, *beside* mksh, which keeps /bin/sh.