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>
Gate 1, item 3, and the last of foundations.md.
bind() creates a T_SOCK node at the path; connect() resolves the path and looks
for the socket bound to **that inode**. Matching on the inode rather than on
the path *string* is the part that matters: the name used to live only in the
socket table, so two spellings of one path missed each other, a relative path
never matched an absolute one, and there was nothing to stat() or unlink().
An inode is the thing a path resolves *to*, so connect() can walk the path
however it likes and arrive at the same socket.
# ls -l /tmp
srwxr-xr-x 1 root root 0 2026-09-22 08:04 socktest
The node is a marker, not the binding. It holds no data and the live
association stays in the socket table, so a socket file left by a crash is
what Linux leaves behind -- a dead file that connect() refuses until something
binds again -- and unlink()ing a live socket's path does not disturb anyone
already connected.
EADDRINUSE comes from the *directory* rather than from a scan of the table,
deliberately: a stale socket file has to refuse a rebind for the same reason a
running server's does, or two servers both believe they own it. The creation
lives in sys_bind() and not in unix.c, because that is the layer with both --
kernel/net/unix.c knows about sockets and has no business calling create().
T_SOCK is a compat addition to SchFS by the rule in schfs.h: a driver that does
not know SCHFS_T_SOCK maps it to a zero-length regular file, so nothing goes
stale and nothing becomes unreadable.
cmd/socktest section 15 asserts the plan's own wording -- bind, stat, see an
`s`, unlink -- plus the two a name table could never fail: a second bind to a
live path is refused, and connecting to a path that is a *regular file* is
refused rather than matched by name.
**And the semantics being real broke socktest on its second run**, correctly:
the socket files persisted and every bind() hit EADDRINUSE. Every real server
unlinks before binding; socktest now does too, which is the change the new
behaviour demands rather than a workaround for it.
Chasing that turned up something worse. `socktest` reported rc=1 with every
check passing, and so did every other first-party program:
- **lib/start.S called main and threw %eax away.** sys_exit() reads the
status from %rdi and nothing put it there, so every program exited with
whatever that register happened to hold. Every test suite ends in
`return failures ? 1 : 0` and none of it reached the shell.
- **exit(void) passed no status either**, for the same reason: the
declaration takes no argument, so %rdi was the caller's litter.
`if socktest; then` works now, and a failing command reports 1 -- checked both
ways, because a fix that makes everything return 0 would look identical from
the success side.
Also factored: unlink_path() out of sys_unlink, so a failed bind can take its
own node back out without going through the syscall entry, and create_sock()
as a named door rather than exporting create() with an arbitrary type.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
`make` had been failing since the e1000 work and I did not see it, because I
was checking build output with `grep error` -- which matches neither "Błąd" nor
mkfs's "image full". Checking the exit status instead found all of this in a
minute.
**usbstick.img was full.** `make ldls-stage` puts a module and its BTF in
sysroot/lib/modules, and a vmlinux BTF is 5 MB on its own; the 16 MB test image
could not hold it. The size cannot move -- tools/windows/bootcheck.ps1 asserts
READ CAPACITY returns exactly 32768 sectors -- so the exclusions grew instead:
lib and usr as well as bin. That image exists to prove the USB driver can read
one block, so its contents were never the point. It also stopped a GPL module
riding into a test artifact, which RAMDISK_EXCLUDE does for the ramdisk and
nothing was doing for this one.
**toybox's httpd was shadowing ours.** /bin/httpd answered `-p` with toybox's
"Unknown option 'p'", because whichever install rule ran second won the name.
TOYBOX_SKIP existed for exactly this and held one entry, `ping`, found the same
hard way. It is now generated from cmd/ -- a list you have to remember is a
list that is wrong the next time cmd/ grows, and it already was: `chvt` had
been silently toybox's, whose VT ioctls are Linux's and not ours.
**ldlsd would not link with clang.** `*out = in;` on a 96-byte struct is a call
to memcpy as far as the C standard is concerned; gcc unrolled it and clang
emitted the call, so a freestanding program linked for months and then did not
on a machine where nothing about it had changed but the compiler. lib/glue.c
now provides memcpy, memmove, memset and memcmp -- the four an implementation
may call without being asked.
**OVMF was never found on NixOS.** `$(dir $(QEMU))share` is the *bin*
directory plus "share", so it looked in /usr/bin/share. The absolute paths
after it covered that up on distributions that keep firmware in /usr; on one
that keeps nothing there it meant the firmware was undiscoverable on a machine
that had it, and the only way to build was to copy the file in by hand. It
resolves the prefix properly now and looks in <prefix>/share/qemu too.
Verified by exit status, from a clean tree and a no-op: both 0. ldls-check
passes 27. The guest boots, serves /srv to the host and answers 403 to
%2e%2e/etc/passwd.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
Porting zsh found four defects in the kernel and one in the filesystem. None
of them were about zsh; all of them had been there the whole time.
**exec threw the environment away.** kernel/fs/exec.c wrote a single zero for
envp with the comment "(no environment)" -- not yet, but ever, for every
process. musl has been passing a perfectly good envp to execve (Linux 59, which
SchOS answers) and it was never read. So $TERM was unset, $PATH was whatever
each program invented, and a variable exported in a shell did not survive the
exec meant to carry it. exec() takes an envp, sys_exec reads argument three,
and schinit manifests grew an Environment key. The userland two-argument
exec(path, argv) stays as a wrapper that passes null explicitly -- the raw stub
is execve now, so a short caller cannot leave %rdx holding a stray pointer.
**Which overflowed the kernel stack.** Three pointer arrays, ~1.8 KB, on a
4096-byte stack, under exec -> loaduvm -> readi -> SchFS -> btree. Pid 1 went
down on the first exec. The canary caught it and named the process, which is
what it is for. They live in one kalloc'd page now.
**waitpid returned a bare -1** for both "no children" and "interrupted". musl
reads [-4095,-1] as -errno, so userspace saw EPERM; zsh printed "wait failed:
operation not permitted" and abandoned the rest of /etc/zsh/zshrc. -ECHILD and
-EINTR now. Third time a bare -1 has cost real time -- on a system with no
permission model, EPERM should be read as "a syscall returned -1".
**NVMA was 64.** musl's allocator takes a mapping per size class and does not
release them eagerly, so compinit ran out of slots and got -1, which is EPERM,
which malloc turns into NULL, which zsh reports as "fatal error: out of memory"
-- on a machine with 1000 MB free. 256 slots, and -ENOMEM.
**And a small write to SchFS costs 58 ms.** 200 writes to one open file take
11.75 s; the same to /dev/null take 0.14 s. That is the design stated at the
top of kmount.c -- one transaction group per operation, and a commit is two
flushes and an uberblock -- not a bug. But compdump writes its digest with
thousands of separate prints, so it takes minutes and looks like a hang.
compinit -D, which skips the dump, finishes in 3.6 s. This one is a decision
rather than a fix, so it is written up and left: /etc/zsh/zshrc keeps compinit
switched off and explains exactly why, with the measurements.
zsh runs as /bin/zsh and is the console shell. ZLE works -- arrow keys recall
history through terminfo, $COLUMNS reads the real 160 because TIOCGWINSZ was
fixed, colour and prompt expansion work, startup is 0.14 s. mksh keeps /bin/sh,
so schinit's no-jobs fallback is a different program from the one that could
have failed.
Also fixed while here: AT_CLKTCK was the literal 100 and is USER_HZ; the
extract rule in four ports could move a source tree inside itself when make
re-ran it, which is how zsh's configure came to write modfile=zsh-5.9/... into
config.modules and fail three steps later.
schfs-check passes. Full writeup in docs/history/kernel.md section 14.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
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.
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.
Nexoniarz