- tty1-tty12 all run login; the image has only root. /dev/tty7..12 could not
be written (cdev.c knew minors 10-16 only), which sent their jobs into a
restart storm that took the supervisor down; fixed, and stat reports them as
Linux's tty7..12.
- Erasing text at a prompt did nothing: erase_one sent a bare backspace, which
only moves; it and the echo path now send back-blank-back through vt_feed.
- A white cursor block was left at the end of every line of a verbose boot:
a line feed at the bottom scrolls the pixels, cursor included, and the
cursor was erased after the scroll. It comes off first now. A blank cell is
also marked dirty, which it was not.
- ldlsd died with a general protection fault on real hardware in its variadic
log function: Linux module code calls with an 8-byte-aligned stack and an
unset %al, and the prologue's movaps faults. LDLS guest code is built with
-mstackrealign.
- make iso took over a minute for any change, because staging r8169 rewrote
the same files and every mtime moved; it now replaces files only if their
contents differ (about 10 s).
- The loader's splash is redrawn in the boot manager's style, and the boot
manager shows its cursor whenever a pointer device exists.
- xf86-input-libinput is out of the image again: with it Xorg took both
keyboard and pointer from libinput and, on the user's laptop, neither worked.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao
- /dev/ptmx and /dev/pts/N: Unix98 pairs with a full line discipline,
window sizes, job control and hangup (kernel/dev/pty.c).
- The console speaks scroll regions, insert/delete line, SU/SD, RI/IND/NEL,
DECSC/DECRC; swallows charset designations and private CSI sequences;
and LF only returns the carriage under ONLCR.
- setsid() drops the controlling terminal, so a pane's pty becomes its ctty.
- pipe2() honours O_NONBLOCK and O_CLOEXEC (libevent's signal pipe).
- File modes are stored and enforced: chmod, fchmod(at), umask, creation
modes; /tmp is 1777.
- /proc/stat has real user/system/idle; /proc/<pid>/task; kthread flag.
- SO_PEERCRED, IOV_MAX 1024.
- /proc/strace: name a program and its syscalls go to the kernel log.
- World gains htop, btop, tmux, mc, ncdu, fastfetch, games, X toys, NetSurf.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
Sixty-five headers sat side by side in include/, so `#include "irq.h"`
said nothing about where irq.h was or what it belonged to, and errno.h,
stat.h and fcntl.h at the top shadowed the system's for any host tool
built with -I./include. They are in folders now -- arch/ core/ fs/
dev/ gfx/ net/ uapi/ (and ldls/ for the Linux driver layer) -- and
every include names the folder, as Linux's do: "core/proc.h".
Done mechanically and checked the hard way: the kernel built from this
tree disassembles identically to the one built from the tree before
it. The full image boots, and userland is the same set of programs.
Paths in docs and comments follow; docs/guides/layout.md has a table
of what is where, and tools/fix-includes.py rewrites old-style
includes from the folders in the tree, for code written before this.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
consoleinit() put consoleread/consolewrite in devsw[1], over memread and
memwrite. Major 1 holds the whole mem major (null, zero, full, random,
urandom) and memread already sends the console's minors to the console,
so the override only broke the others: a read of /dev/zero waited for a
typed line. dd and head on either device hung, and `head -c 10 /dev/zero`
only finished because it swallowed the next command.
The console now installs just its open and close hooks. /dev/keyboard
writes are discarded, as consolewrite used to do.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
A program that wants to make a sound opens /dev/dsp, writes PCM, and closes
it. That is what UNIX audio has always been and it now exists here:
tone 440 2
Three pieces, in the order a sample passes through them. **/dev/dsp** is a
character device where write() is audio and a handful of OSS ioctls say what
the samples are. **AudioEngine** is everything above a driver that is not
specific to a chip -- the format, whether there is room, and what a write does
when there is not. **A driver** is bound by class, exactly as a display driver
is: device_find_class(DEVCLASS_AUDIO).
OSS numbering rather than something new, because every UNIX audio program ever
written already knows it and the only thing a different set would achieve is
making ports harder. They are read/write ioctls, which is the part that
matters: a program asks for 44100, the device sets 48000 and writes 48000
back, the program resamples. One that ignores the answer plays 9% fast, and
that is its bug rather than the driver's.
**The engine is deliberately one stream.** Mixing several programs is a real
feature with a real design behind it, and building it before anything had
played a single sound would be exactly what docs/plan/1.0.md keeps a register
for: work that exists and is connected to nothing. The second program that
wants to play at the same time is what should cause it to be written.
**audio_wait() sleeps on the timer tick, not on the device.** That looks like
the lazy choice and is not: a ring that drains is a ring with room, so asking
again in ten milliseconds always makes progress, whereas sleeping on the card
makes audio depend on an interrupt arriving. On a machine whose line is
misrouted that is not a stutter, it is a writer that never wakes. The handler
still accounts for finished buffers -- deleting it would cost efficiency, not
correctness -- and it retires descriptors through the same `tail` pointer
queue() uses, so the two cannot disagree about what is in flight.
**AC'97 first because HDA is two unproven things at once.** It is the simplest
audio device that exists on real machines and in QEMU both. Intel HDA is what
the laptop actually has and is a much larger driver; writing it against an
interface nothing had ever played through would have meant debugging the
driver and the interface simultaneously. HDA arrives as a second
struct audio_ops and nothing above it changes -- which is the entire point of
the class.
Two things the wiring needed: PCI class 0x04 now maps to DEVCLASS_AUDIO (the
driver bound and /proc/devices showed it, but audio_get() found nothing,
because the class byte had never been translated), and include/x86.h grew
inw() -- AC'97's mixer is all 16-bit registers and reading one a byte at a
time returns the low half twice on some codecs.
**Tested by measuring what came out, not by not crashing.** QEMU's wav backend
writes the guest's audio to a file; `tone 440 2` produced 1.97 seconds of
44.1 kHz stereo with peak amplitude 14177 against the generator's table
maximum of 14178, and 880 zero crossings per second -- 440 Hz exactly. wav is
on every QEMU target rather than a host backend, because a build machine may
have no sound card and it is the only backend whose output can be checked.
Both supported configurations: one boot each, no traps, no panics, socktest
and memfdtest green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Ctrl-C killed the shell. consoleread() breaks off the read in progress when
SIGINT arrives and returned -1 to do it -- and -1 is -EPERM by the time it
reaches a program, so every program that handles SIGINT by carrying on saw a
permanent error instead of an interrupted call:
zsh: error on TTY read: operation not permitted
schinitd: restarting os.schos.console-shell
and the next Ctrl-C did it to the replacement. EINTR now, which is what a
signal-interrupted read is required to give. Verified: Ctrl-C an interruptible
command, shell survives, zero restarts.
Same mistake, same file family: link, unlink, rename and renameat returned -1
on every error path. Callers branch on errno -- `if (unlink(p) < 0 && errno !=
ENOENT)` is the standard shape, and against EPERM it always complains -- which
is why zsh reported failures for things that had worked. They return ENOENT,
EEXIST, EXDEV, EISDIR, ENOTEMPTY and EFAULT now. About ninety other `return -1`s
remain in sys_fs.c; these four are done because these four were what a program
tripped over. /dev/mem's unknown minors return ENODEV rather than -1 too.
/dev/urandom was a linear congruential generator seeded with a **constant**, so
every boot produced the same bytes in the same order -- not weak, the same. A
key, a nonce, a temporary filename: shared with every SchOS machine that had
ever run. Seeded at boot from RDRAND where the CPU has it, from the cycle
counter and the wall clock where it does not, and re-stirred per byte. Still an
LCG and still not a CSPRNG; what changed is the part that was dangerous rather
than merely poor.
**Not fixed, and recorded as such:** rename() still will not replace an existing
target, so zsh's history save fails on every exit after the first. An attempt to
unlink the target first was reverted -- the directory is an HTree, dirunlink
followed by dirlink of the same name did not behave, and it panicked in
filewrite with the old file already gone. Losing both files is worse than
refusing, so it refuses until the HTree's slot reuse is understood.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
schdbgd bridges TCP to the debugger, which is the one way in that does not
need you to be sitting at the machine. It is a bridge and nothing else: a line
in becomes a line written to /dev/dbgro and the answer comes back, so `nc` is a
complete client and there is no clever client to be broken on the day you need
this.
# schdbgd &
schdbgd: debugger on port 4444, loopback only
$ nc 127.0.0.1 4444
dma
arena 0xffff80003da41000-0xffff80003ea41000 16384 KB total, ...
A kernel debugger plus a TCP socket is a remote root hole, so three things were
decided rather than discovered:
- It does not start by itself. schdbgd.job ships Disabled. SchOS has no
kernel command line, so the boot flag the plan asked for is the job
manifest, which is the same thing in this system's own idiom.
- It binds loopback; -a names an address and says so in a paragraph.
- It cannot reach a view that changes state, enforced in the kernel.
That last one is /dev/dbgro: /dev/dbg on minor 1. The minor is the one piece of
per-open state a character device already sees, so which node you opened is the
permission -- nothing to latch, nothing to remember between the write and the
read, no way across. Which views are refused comes from dbg_register_rw() on
the registration itself, because a central list of dangerous views goes stale
in the direction where a new view is quietly treated as safe. Today that is
`watch <addr>`; `watch` with no argument is still the listing and still
answered.
Also: socket() now accepts IPPROTO_TCP with SOCK_STREAM and IPPROTO_UDP with
SOCK_DGRAM. They name the default rather than departing from it, and toybox's
nc writes them out -- so TCP was "Protocol not supported" on a system whose
whole network is TCP.
docs/plan/debugger.md retires into docs/architecture/debugging.md; 16 files
repointed. Every plan in docs/plan/ that was open is now closed, so the next
thing is Gate 0 itself: the survey, with the instrument built.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
docs/plan/ldls.md L3a -- the class bridge, and the first of the three pieces
L3 turned out to be.
/dev/netdev is /dev/pci with the arrows reversed. That hands a device to a
process; this lets a process be one. The kernel side is netdev_ops and nothing
else -- transmit, receive, mac, link_up, the same four entries e1000
publishes -- so a process claims the device, supplies a MAC, and from then on
read() gives it frames the stack wants sent and write() hands it frames that
arrived.
cmd/netecho proves it and is deliberately not a driver: no hardware, none
claimed, every frame answered by the program itself. DHCP so the interface
gets an address at all, ARP so the stack can find it, ICMP so it can be
pinged. All built by hand from RFCs 826, 791, 792 and 2131.
# netecho &
netuser: ldls0 is a process now, 2:4c:44:4c:53:1
netecho: I am 10.9.0.1 and will offer 10.9.0.2
netecho: answered DHCP, offering an address
# cat /proc/netif
interface ldls0 driver netuser address 10.9.0.2 gateway 10.9.0.1
# ping 10.9.0.1 3
netecho: answered an ARP
netecho: answered a ping
3 packets transmitted, 3 received, 0% packet loss
The interface got its address by DHCP from a process and then answered ping
from one. lwIP never learns that the thing behind netdev_ops is not a driver,
which is the whole property the bridge exists to have.
It dies the way it should, too. kill the process and link_up() answers false
immediately, so the stack refuses to send -- "ping: sendto: -5" -- rather than
swallowing packets into a driver that is not there. Start another and the
*same* interface comes back, keeping its address. That came free:
netuser_release_all() sits beside pciuser_release_all() in exit() for exactly
the same reason, and the reason is that a process holding a device is one that
may crash.
One thing the kernel needed: netinit() starts DHCP on the devices that exist
when it runs, so an interface created later -- which is how an LDLS-hosted
driver arrives -- would have come up with no address and no way to get one.
net_attach_late() fixes that, and lives in kernel/net/net.c because that is
the only file allowed to include lwIP's headers.
Recorded as not done, because it is not: this proves the bridge, not a driver.
Nothing in that test loads a module. That is why it was done first -- if ping
had not worked here the bridge would be wrong, and now a failure with a real
driver can only be the driver's side. L3b is the SchOS-side host, L3c is the
fifteen symbols for real, and L3 is the two joined.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
docs/plan/debugger.md, milestones D0, D1 and D2. What they replace is the
ninety-second loop -- add a cprintf, rebuild, boot, read the serial log --
which answers exactly the one question you thought of before the rebuild.
The rule the shape follows: **it observes, it does not control.** No
stepping, no software breakpoints, no stopping the world. Half the bugs
this kernel produces are timing -- an interrupt storm, a level-triggered
line nobody acknowledges, a driver that faults only on its second start --
and every one of them disappears when you halt the machine to look. And
the layering rule, which is the circularity rule the display already has:
a debugger that needs lwIP cannot debug lwIP.
D0 -- symbols. tools/ksyms.pl turns the first link pass into a table the
second pass carries. Two passes is enough because .ksym is placed after
.text and .rodata, so carrying the table cannot move anything recorded in
it; the build lists both passes' text symbols and refuses to link if they
ever disagree, because a symbol table that is subtly wrong gives confident
false answers. ksym.c reads it through weak symbols, so pass one -- which
has no table -- still links. A crash chain now reads panic+0x5f <-
proc_sysrq_cmd+0x99 <- ... <- syscall+0xf6.
D1 -- a log that outlives the kernel. Every character through consputc()
lands in a byte ring with a timestamp per line, readable as /proc/kmsg.
It sits in a region carved before the page allocator gets anything, with a
magic header, so a kernel finds the previous kernel's log still there --
including the whole PSOGM report. panic.c's own comment said "there is no
core dump and no log to go back to"; that is no longer true.
The obvious place for it is the top of RAM beside the DMA arena. That
was the first attempt and the magic came back as ASCII on the reboot,
because the top of usable memory is exactly where the firmware makes its
own allocations. It lives above the kernel image instead, which is a
stable address across boots of the same build.
D2 -- the introspection registry. A subsystem publishes its state with one
line at the bottom of the file that owns the data:
dbg_register("dma", dma_dump, "the DMA arena's free extents");
Seven views -- dma, mem, proc, vma, claims, pci, sock -- reachable three
ways: sysrq 'g' (always, no process and no filesystem), /dev/dbg (echo a
line, cat the answer), and schdbg. The protocol is lines of text because
the same bytes have to work where nothing can allocate or frame a record,
and because a protocol you cannot drive by hand is one you cannot debug.
struct sbuf moved out of kernel/dev/procfs.c into include/sbuf.h rather
than being written a second time.
Several views exist because of a specific bug. `vma` is the table that
decides whether exit() frees a page, and the DMA ownership bug that made
this worth building was a block that was never in it.
Also fixed, found by building with clang for the first time in a while:
struct iovec was defined in both posix.h and socket.h, and every file that
included both was a redefinition. GCC 15 defaults to C23, which permits an
identical struct redeclaration, so the gcc path never noticed -- while
clang defaults to gnu17 and rejected it, breaking the one toolchain
shell.nix exists to provide and the UEFI loader requires. Both are now
guarded.
D3 (`whose <addr>`, the cross-subsystem ownership query) and D4 (hardware
watchpoints on DR0-DR3) are not built and are described honestly as
missing in the architecture doc's "What it does not do".
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
docs/plan/hybrid.md mechanisms 2 and 4: MMIO and DMA to a process.
A process can enumerate the bus, claim a device exclusively, map its BARs and
get memory the device can be pointed at. Proven end to end against an e1000e
-- the exact device class we cannot drive and would want a foreign driver for:
device 7: 8086:10d3 (network)
claimed
BAR0 at 0x81060000, 128 KB
regs[0..3] = 0x00140261 0x00000000 0x00080283 0x00000000
MMIO reaches the device
DMA 8 KB at virtual 0x40001000, physical 0x3f8eb000
Those are the e1000e's CTRL and STATUS with full-duplex and link-up set, which
is how you tell a real mapping from one reading 0xFFFFFFFF off an unmapped
address. Claiming a device the kernel drives is refused -- two writers of one
register set looks like hardware that has started lying -- and everything a
process held is released when it exits, because a driver that crashed must not
keep its hardware away from its replacement.
mmap's offset is the BAR's physical address, checked against the BARs of
devices *this process has claimed*. Without that check the device is /dev/mem
with extra steps and a process could map the kernel's own memory. Mappings are
write-through: a cached write to a doorbell arrives whenever the cache feels
like it, which from a driver's side is indistinguishable from hardware that
ignores you.
The interface is about PCI devices, not about any driver model, and its first
users will be SchOS's own drivers when virtio-gpu is evicted. That ordering is
the design rather than an accident: an interface whose first consumers are
native drivers is a general mechanism something foreign can use later, instead
of a hole shaped like something foreign.
Also: PROT_* and MAP_* moved to include/posix.h. They were defined only in
sys_mem.c, so cmd/fbinfo carried a private copy and this wanted a third --
two copies of a number the kernel compares against, where a mismatch shows up
as a mapping with the wrong permissions rather than an error.
No IOMMU, so this isolates a driver against its own bugs and not against its
own DMA. The plan says so at length and it is still true.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
/dev/tty1..tty6, Alt+F1..F6 or `chvt N`. Each is an independent terminal --
its own screen, cursor, line discipline, foreground process group and
session. Two shells on two terminals are unrelated processes that share a
keyboard and a screen.
What made it possible is a backing store. The console drew straight into the
framebuffer and scrolled by moving pixels, which works exactly as long as
nothing else wants the screen: there was nowhere to put terminal 2 while
terminal 1 was visible, and nothing to repaint terminal 1 from. Each terminal
owns a grid of cells now and the framebuffer shows whichever grid is active,
so vt_switch() is set-index, repaint, return -- nothing is saved on the way
out because the outgoing grid has been current all along.
The rule the layer is built on: a terminal does not know whether it is
visible. Writes land in the grid, the cursor moves, the grid scrolls, all
unconditionally; drawing is one question asked at the bottom of vt.c. Every
alternative spreads "am I on screen" through the escape parser, and then a
terminal switched away from mid-sequence comes back wrong.
Everything that was a single global is per-terminal now: tty_fg_pgrp (deleted),
termios, the input ring, the escape parser, the UTF-8 decoder, and the cursor
-- which also stops being pixels in gfx.c and becomes cells in the terminal.
TIOCSCTTY was `return 0` and now records proc->ctty, which is what /dev/tty
resolves through; /dev/tty was an alias for /dev/console with the same minor,
and they are different questions.
kbd.c names Alt+F1..F6 as KEY_ALT_F1+n, above 0xFF on purpose -- every byte
value is already a character or a UTF-8 continuation, and a chord colliding
with one would be typed into the terminal instead of switching away from it.
What the chord means is decided in console.c, where the terminals are.
VT_ACTIVATE / VT_WAITACTIVE / VT_GETSTATE / VT_OPENQRY, Linux's numbers.
The argument to ACTIVATE is by value, not a pointer -- same shape as TCFLSH.
Two bugs found by screenshotting the result rather than reading the log:
- zsh emits 0x0F to leave alt-charset mode, because that is what the `linux`
terminfo says rmacs is, and the console drew CP437 glyph 0x0F: a sun, in
the prompt, on every line. A terminal never draws a C0 control character.
- SGR 7 was unimplemented, so zsh's partial-line marker rendered as a bare
'#' instead of a reversed block. Reverse video swaps the colours at draw
time, not at store time, so turning it off restores what was underneath.
Verified by screendump: tty1 and tty2 show different screens, and switching
back repaints tty1's earlier content from its grid. schfs-check passes.
docs/architecture/terminals.md, including what it does not do -- no
scrollback, no reflow, no VT_PROCESS mode for a display server to veto a
switch, which Schcom will need before it owns Alt+F7.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VQ7Qx8E1q1M1bbCq8QLHS2
struct file already carried a uint64 offset and bread already took a
uint64 block number. The narrowing was one boundary in the middle:
devsw's read and write took a 32-bit uint, so fileread passed a 64-bit
f->off into a 32-bit parameter and the top half was discarded.
The effect was not a refusal at 4 GB but silent wraparound past it. A
read at 5 GB returned the bytes at 1 GB, reporting success. disk.c had a
DISK_MAX_BYTES constant documenting the limit, and nothing anywhere
referenced it -- the cap was described but never enforced, which is the
worst of the three options.
The signature is now uint64 across all nine files that carry it, and
diskread/diskwrite no longer narrow the block number on the way to
bread. Widening this is a prerequisite for NVMe and for any real disk:
namespaces start well above 4 GB and the failure mode reads valid data
from the wrong place.
Verified end to end rather than by inspection. A 6 GB sparse image with
"PAST4GB-MARKER-OK" written at byte 5368709120, attached as /dev/hdb to a
ramdisk-root kernel so device 1 was free:
# dd if=/dev/hdb bs=4096 skip=1310720 count=1 | od -c | head -2
0000000 P A S T 4 G B - M A R K E R - O
Under the old code that offset truncates to 1 GB, where the image is
zeroes. The whole path is exercised: f->off, devsw, diskread, bread and
ide.c's LBA48.
Worth recording for next time: `make ramroot` stages the ESP itself, and
running `make esp` afterwards rebuilds the kernel without RAMROOT and
silently undoes it. The tell is a 855 KB kernel where a 25 MB one is
expected.
110 [ok], no failures, on the default build.
Nothing outside the kernel could touch a disk. sys_mount does not even
look at the device it is handed -- it mounts the one SchFS volume found
at boot and ignores `source` -- so a program had no way to read a
partition table, format a volume or write a boot sector. An installer is
a program that needs all three, so this is the first piece of it.
A character device in devsw rather than a separate block layer, because
that is where the offset already lives: fileread/filewrite pass f->off
and advance it by what comes back, which is everything a seekable device
needs. The minor is the IDE device number, the same numbering iderw()
uses; two schemes for the same disks would be a bug waiting to happen.
Writes bypass every filesystem above them, which is inherent to a raw
device and why an installer must target a disk it has not mounted.
The nodes are created unconditionally, like every other entry in /dev.
That matters more than it looks: with no node, `echo x > /dev/hdb`
silently creates an ordinary file of that name and appears to work. It
did, and it agreed with itself on read-back; only the host's copy of the
disk showed nothing had been written.
st_rdev was never filled, so every node in /dev reported "0, 0" under
ls -l. Harmless while nothing read it, wrong as soon as something has to
tell two disks apart. Filled with the full Linux dev_t encoding rather
than (major << 8 | minor), which only works while both stay small.
Verified against the host as an independent oracle, both directions: the
guest wrote to /dev/hdb and the host saw those bytes at offset 0; the
host wrote at offset 4096 and the guest read them back with dd skip=.
ls -l now shows 1,1 for console, 2,0 for fb0 and 8,1 for hdb.
Known limit, commented in disk.c: devsw passes the offset as a 32-bit
uint, so a raw disk is addressable to 4 GB. That must be widened before
anyone installs onto a real disk.
bootcheck 108 [ok] with -Fb -Tty -Usb -Sock -Evdev -Ps.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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.