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kbd: three layouts, and the arrow keys were sitting on top of UTF-8

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`∞`, `→`, `≤` and `'` could not be typed. `ą` and `ę` could. That pairing is
the whole diagnosis: KBD_UP was 0xE2 and its neighbours filled 0xE0..0xE9,
which are exactly the UTF-8 lead bytes for three-byte characters. Every
character in U+0800..U+FFFF -- most punctuation, every arrow, every maths
symbol, the whole of CJK -- arrived as a value the console read as an arrow key
and helpfully turned into `ESC [ A`. Two-byte sequences lead with 0xC4 and
nothing claimed 0xC4, so Polish came through and the rest did not.

The chord codes already knew this rule and said so in a comment. The navigation
keys predate them and were never brought in line. Stated once, in kbd.h: a key
produces either a Unicode codepoint or a value above 0x10FFFF, and nothing in
between means anything. KEY_* -> KBD_*, which also settles a silent collision
-- include/input.h defines its own KEY_HOME, KEY_UP and KEY_END as evdev
numbers, and kbd.c includes both headers, so three macros were being quietly
redefined in the one file that used them.

Then the layouts, which is what the codepoint-sized keycodes were for.

kernel/dev/keymap.c: us, pl, de. A layout is four tables -- plain, Shift,
AltGr, Shift+AltGr -- of uint32 codepoints. uint32 and not uchar is the reason
the file exists: `ó` fits in a byte and `ą` does not, and half a Polish
alphabet is not a Polish layout.

Two things deliberately are *not* tables:

  - **Ctrl is derived from the plain codepoint.** The table it replaces was
    indexed by scancode, which quietly assumed US -- on QWERTZ the Y and Z keys
    swap, so Ctrl+Z would have suspended a job only on some layouts.
  - **Caps Lock is a case toggle on the result**, so AltGr+a with Caps Lock is
    `Ą`. No second table could say that, because Caps Lock combines with AltGr
    rather than replacing it. Latin Extended-A alternates upper/lower by
    codepoint but not all the same way round -- Ł is U+0141 (odd) and Ą is
    U+0104 (even) -- so Polish lands in both halves and the parity matters.

kbdgetc() encodes to UTF-8 and returns the bytes one call at a time.
consoleintr()'s contract is bytes: the serial line hands it UTF-8 already and
it could not tell an encoded codepoint from a byte of the same value.

The layouts live in the kernel. Linux's loadkeys compiles a text keymap and
uploads it a key at a time through KDSKBENT, which puts the data in userspace
-- and a machine whose /usr has not mounted then has no layout at all. Here the
kernel always has a working keyboard and `loadkeys` only names which one.
KB_GETLAYOUT/KB_SETLAYOUT/KB_LISTLAYOUT; /etc/vconsole.conf and an
os.schos.keymap job for the boot-time choice. No dead keys, so French and
Spanish are absent rather than wrong.

/etc/locale.conf and LANG=C.UTF-8 in profile and zshenv. Only the charset half
of that is real -- musl decodes UTF-8 whatever the locale says and ships no
locale data -- but an unset LANG reads as "ASCII only" to everything that asks,
which is its own way of producing `?`.

And two symlink bugs found while chasing

    zsh: locking failed for /root/.zsh_history: operation not permitted

on every boot. symlink() is the classic atomic lock -- create the link, and if
it exists someone else holds it -- and zsh distinguishes EEXIST ("contended,
retry") from anything else ("this cannot work, give up"). sys_symlink returned
a bare -1, which is -EPERM, so every zsh on the machine took the second branch
on a filesystem that supports symlinks perfectly well. Same errno class as
commit 75ccf98.

The second one the first was hiding: **divesymlink() has been in fs.c since the
fork and nothing ever called it.** A symlink behaved as a small file containing
its own target, so `cat link` printed the target's *name*. open() and openat()
follow the final component now (O_NOFOLLOW gives ELOOP), and stat() and lstat()
stop being the same function, since which one follows is the only difference
between them. Mid-path symlinks are still not resolved -- that belongs in
namex(), which would re-enter lookup holding a directory lock.

Verified on the emulated keyboard, not just over serial: AltGr+a/e/s gives
ąęś, Shift+AltGr gives ĄĘŚ, Caps Lock+AltGr gives ĄĘŚ, de types zy for the
physical y/z keys and @€µ on AltGr. `∞ 'x' → ≤ • — …` typed over serial now
survives. Three fresh boots: 0 lock failures, 0 faults.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
Nexoniarz 2026-09-20 01:09:32 +02:00
commit 4e3e345b41
15 changed files with 994 additions and 208 deletions
Download patch file Download diff file Expand all files Collapse all files

4
Makefile
View file

@ -24,7 +24,7 @@ KERN_CORE = $(addprefix $(BUILD)/kernel/core/, \
panic.o uaccess.o qr.o time.o ksym.o klog.o sbuf.o)
KERN_DEV = $(addprefix $(BUILD)/kernel/dev/, \
bio.o cdev.o device.o disk.o fb.o ide.o input.o irq.o kbd.o mouse.o \
bio.o cdev.o device.o disk.o fb.o ide.o input.o irq.o kbd.o keymap.o mouse.o \
pci.o pciuser.o text.o ttf.o uart.o gfx.o vt.o ramdisk.o procfs.o \
dbg.o netuser.o)
@ -108,7 +108,7 @@ KERN_NOENTRY = $(filter-out $(BUILD)/kernel/arch/x86_64/entry.o, $(KERNOBJS))
# Third-party software does NOT go here — see ports/.
# -----------------------------------------------------------------------
ULIB = $(addprefix $(BUILD)/lib/, start.o glue.o usys.o)
CMDS = schinit schinitd fbinfo shmtest socktest inputtest nettest reflink schattr ping chvt pcitest vgpud schdbg schdbgd resolvconf httpd schmode netecho ldlsd
CMDS = schinit schinitd fbinfo shmtest socktest inputtest nettest reflink schattr ping chvt loadkeys pcitest vgpud schdbg schdbgd resolvconf httpd schmode netecho ldlsd
CMDBINS = $(addprefix $(BUILD)/cmd/, $(CMDS))
# -----------------------------------------------------------------------

184
cmd/loadkeys/main.c Normal file
View file

@ -0,0 +1,184 @@
// SPDX-License-Identifier: Apache-2.0
//
// loadkeys -- choose the keyboard layout.
//
// loadkeys print the active layout
// loadkeys -l list the layouts the kernel has
// loadkeys pl switch to Polish (programmers)
// loadkeys -c apply KEYMAP from /etc/vconsole.conf
//
// Named after the Linux tool because that is what anyone would type, but it is
// not the same program and takes no keymap files. Linux's loadkeys compiles a
// text keymap and uploads it a key at a time through KDSKBENT, which means the
// data lives in userspace and a machine whose /usr is not mounted has no
// layout at all. The layouts here are in the kernel and this only names one.
//
// The setting is machine-wide, not per-terminal: there is one keyboard, and
// switching to tty3 does not move anybody's fingers.
#include "types.h"
#include "user.h"
#include "fcntl.h"
#include "posix.h"
// No printf, memset or strcpy in lib/; this needs a little of each.
static void
puts_(const char *s)
{
int n = 0;
while (s[n]) n++;
write(1, (void *)s, n);
}
static void
zero(void *p, int n)
{
char *c = p;
while (n-- > 0) *c++ = 0;
}
static void
copy_bounded(char *dst, const char *src, int cap)
{
int i = 0;
while (i < cap - 1 && src[i]) { dst[i] = src[i]; i++; }
dst[i] = 0;
}
// /dev/console rather than fd 0: the caller may have redirected its input,
// and the layout being set belongs to the machine's keyboard, not to whichever
// terminal this process happens to be reading from.
static int
console(void)
{
int fd = open("/dev/console", O_RDWR);
if (fd < 0) {
puts_("loadkeys: no console to ask\n");
exit();
}
return fd;
}
#define VCONSOLE "/etc/vconsole.conf"
// Pull KEYMAP= out of /etc/vconsole.conf.
//
// Deliberately not a config parser. One key, whole file in one buffer, first
// match wins -- and a missing or unreadable file is not an error, because the
// kernel's default is already a working keyboard and refusing to boot over a
// preference would be absurd.
static int
keymap_from_file(char *out, int cap)
{
char buf[512];
int fd, n, i, j;
fd = open(VCONSOLE, O_RDONLY);
if (fd < 0)
return -1;
n = read(fd, buf, sizeof(buf) - 1);
close(fd);
if (n <= 0)
return -1;
buf[n] = 0;
for (i = 0; i < n; i++) {
if (buf[i] == '#') { // skip to end of comment
while (i < n && buf[i] != '\n') i++;
continue;
}
if (buf[i] != 'K')
continue;
const char *k = "KEYMAP=";
for (j = 0; k[j] && buf[i + j] == k[j]; j++)
;
if (k[j])
continue;
i += j;
for (j = 0; j < cap - 1 && buf[i + j] &&
buf[i + j] != '\n' && buf[i + j] != ' '; j++)
out[j] = buf[i + j];
out[j] = 0;
return j > 0 ? 0 : -1;
}
return -1;
}
int
main(int argc, char *argv[])
{
struct kb_layout k;
char want[16];
int fd, i;
if (argc > 2 || (argc == 2 && argv[1][0] == '-' &&
argv[1][1] != 'l' && argv[1][1] != 'c')) {
puts_("usage: loadkeys [-l | -c | <layout>]\n"
" -l list the available layouts\n"
" -c apply KEYMAP from " VCONSOLE "\n"
" <layout> switch to it; with no argument, print the active one\n");
return 1;
}
fd = console();
if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'c') {
if (keymap_from_file(want, sizeof(want)) < 0) {
close(fd);
return 0; // no preference recorded; not a failure
}
zero(&k, sizeof(k));
copy_bounded(k.name, want, sizeof(k.name));
if (ioctl(fd, KB_SETLAYOUT, &k) < 0) {
puts_("loadkeys: " VCONSOLE " asks for '");
puts_(want);
puts_("', which this kernel does not have\n");
close(fd);
return 1;
}
close(fd);
return 0;
}
if (argc == 2 && argv[1][0] == '-') { // -l
for (i = 0; ; i++) {
zero(&k, sizeof(k));
k.index = i;
if (ioctl(fd, KB_LISTLAYOUT, &k) < 0)
break; // past the end
puts_(k.name);
puts_("\t");
puts_(k.desc);
puts_("\n");
}
close(fd);
return 0;
}
if (argc == 2) { // set
zero(&k, sizeof(k));
copy_bounded(k.name, argv[1], sizeof(k.name));
if (ioctl(fd, KB_SETLAYOUT, &k) < 0) {
puts_("loadkeys: no layout called '");
puts_(argv[1]);
puts_("' -- try loadkeys -l\n");
close(fd);
return 1;
}
close(fd);
return 0;
}
zero(&k, sizeof(k)); // report
if (ioctl(fd, KB_GETLAYOUT, &k) < 0) {
puts_("loadkeys: the kernel has no layout to report\n");
close(fd);
return 1;
}
puts_(k.name);
puts_("\t");
puts_(k.desc);
puts_("\n");
close(fd);
return 0;
}

91
docs/architecture/terminals.md
View file

@ -109,17 +109,74 @@ Linux's numbers, because they do Linux's job.
| `VT_GETSTATE` | active terminal and a bitmask of those in use |
| `VT_OPENQRY` | the first terminal nobody has open |
| `VT_GETMODE`/`VT_SETMODE` | accepted and ignored — the kernel drives switching and there is no process mode to set |
| `VT_GETCHORD`/`VT_SETCHORD` | SchOS's own: which key combination switches. See below |
| `KB_GETLAYOUT`/`KB_SETLAYOUT`/`KB_LISTLAYOUT` | SchOS's own: the keyboard layout, by name |
## The keyboard
`kbd.c` recognises Ctrl+Alt+Shift+F1..F6 and returns `KEY_VT_SWITCH + n`, which is above
0xFF on purpose: every value that fits in a byte is already either a character
or a UTF-8 continuation byte, and a chord that collided with one would be typed
into the terminal instead of switching away from it.
`kbd.c` turns scancodes into characters and chords. `keymap.c` holds the
layouts. Between them is one rule, and it is the rule the whole keycode space
is built around:
> **A key produces either a Unicode codepoint or a value above `0x10FFFF`.
> Nothing in between means anything.**
The chord codes always obeyed it. The navigation keys did not: `KEY_UP` was
`0xE2`, and `0xE0..0xE9` are exactly the UTF-8 lead bytes for three-byte
characters. Typing any of U+0800..U+FFFF — most punctuation, every arrow, every
maths symbol, the whole of CJK — produced a value the console read as an arrow
key and turned into `ESC [ A`. `∞`, `→`, `≤` and `'` vanished from the input
line while `ą` and `ę` came through, because those are two-byte sequences whose
lead byte is `0xC4` and nothing claimed `0xC4`. They are `KBD_*` now and sit
above every codepoint there is.
What the chord *means* is decided in `console.c`, where the terminals are. The
keyboard driver names it and stops.
### Layouts
Three, in the kernel: `us`, `pl` (Polish programmers), `de` (QWERTZ). `loadkeys`
lists and switches them; `/etc/vconsole.conf` records the choice and the
`os.schos.keymap` job applies it at boot.
**In the kernel, not in files.** Linux's `loadkeys` compiles a text keymap and
uploads it a key at a time through `KDSKBENT`, which puts the data in userspace
— and a machine whose `/usr` has not mounted then has no layout at all. Here
the kernel always has a working keyboard and userspace only names which one.
A layout is four tables of codepoints — plain, Shift, AltGr, Shift+AltGr —
indexed by scancode. Two things are deliberately *not* tables:
- **Ctrl is derived from the plain codepoint**, not looked up. The table it
replaced was indexed by scancode, which quietly assumed US: on QWERTZ the Z
and Y keys swap, so Ctrl+Z would have suspended a job only on some layouts.
- **Caps Lock is a case toggle on the result**, so `ą` from the AltGr level
becomes `Ą` — which no second table could have said, because Caps Lock
combines with AltGr rather than replacing it.
Codepoints and not bytes is the entire point: `ó` fits in Latin-1 and `ą` does
not, and half a Polish alphabet is not a Polish layout. `kbdgetc()` encodes to
UTF-8 and hands the bytes to `consoleintr()` one call at a time, because that
function's contract is bytes — the serial line delivers UTF-8 already and
nothing could tell an encoded codepoint from a byte of the same value.
**No dead keys.** On a real German layout the acute and circumflex keys wait
for the next key and combine; here they type the accent alone. It needs
per-keyboard pending state that this interface has no room for, so layouts that
depend on it — French AZERTY, Spanish — are not shipped rather than shipped
wrong.
### Locale
`/etc/locale.conf`, read by `/etc/profile` and `/etc/zsh/zshenv`, default
`LANG=C.UTF-8`.
**Only the charset half of it is real.** musl decodes and encodes UTF-8
whatever the locale says and ships no locale data, so collation stays codepoint
order and messages stay English whichever language is named. What `LANG` does
is tell the programs that ask that the terminal is UTF-8 — an unset `LANG`
reads as "ASCII only", and that is what makes a program fall back to `?`.
### The chord is a setting, and that is the point
**There is no combination that is free for everyone on every host**, and a
@ -273,13 +330,15 @@ Two bugs, both in the same half-second of using a shell, and both worth
recording because the symptom pointed away from the cause.
**Arrow keys corrupted the next two keystrokes.** They arrive from the keyboard
as single keycodes -- `KEY_UP` is `0xE2` -- and were pushed into the input
buffer exactly like that. No terminal has ever worked that way, and `0xE2` is
the worst byte to have picked: it is a UTF-8 lead byte for a three-byte
character, so a reader decoding UTF-8 swallowed the *next two keys* waiting for
continuations that never came. `consoleintr()` translates them to the DEC/xterm
sequences now -- `ESC[A`, `ESC[D`, `ESC[5~` and the rest -- which is what every
terminfo entry and every line editor already expects.
as single keycodes and were pushed into the input buffer exactly like that. No
terminal has ever worked that way. `consoleintr()` translates them to the
DEC/xterm sequences now -- `ESC[A`, `ESC[D`, `ESC[5~` and the rest -- which is
what every terminfo entry and every line editor already expects.
The *value* those keycodes had was a second bug wearing the same coat, and it
outlived the fix: `KEY_UP` was `0xE2`, a UTF-8 lead byte, so a character typed
from the other direction was eaten just as thoroughly. See the keycode rule
above.
**Then the end of the line vanished as you typed into it.** With the arrows
working, editing mid-line left the buffer perfectly correct and the screen
@ -331,7 +390,9 @@ waiting for a different editor.
advance. Combining marks land on top of their own cell rather than the
preceding one, and CJK draws at half the width it wants. Both need a
width table and a cell that can span two columns.
- **Typed input above U+07FF is unreliable.** Two-byte UTF-8 arrives intact;
three-byte sequences typed at the shell come through mangled. The console's
own decoder is not the problem — the same characters `cat`ed from a file
render correctly — so this belongs with keyboard and locale handling.
- **No dead keys**, so French and Spanish layouts are absent rather than
broken. See above.
- **No per-terminal layout.** One keyboard, one layout. Switching to tty3 does
not move anybody's fingers.
- **Only three layouts.** Adding one is a table in `keymap.c` and a line in the
catalogue; the mechanism is not the limit, the typing is.

17
etc/locale.conf Normal file
View file

@ -0,0 +1,17 @@
# /etc/locale.conf — the system locale.
#
# Same name and same format as systemd's, because it is the file anyone would
# look for and there is nothing to gain by inventing a third convention.
#
# **Only the charset half of this is real.** SchOS's libc is musl, which
# decodes and encodes UTF-8 whatever the locale says and ships no locale data
# at all -- so collation is still codepoint order, and messages are still
# English, whichever language is named below. What LANG does here is tell the
# programs that ask that the terminal is UTF-8, which is what stops them
# falling back to ASCII-only output.
#
# C.UTF-8 says exactly that and claims nothing else. A regional value
# (pl_PL.UTF-8, de_DE.UTF-8) is accepted and behaves identically today; set it
# if you want the intent recorded.
LANG=C.UTF-8

9
etc/profile
View file

@ -4,6 +4,15 @@ export PATH=/bin:/sbin:/usr/bin
export HOME=/
export TERM=vt100
# The locale, from /etc/locale.conf if it says anything. Only the charset half
# of it means much here -- see that file -- but a program that has to guess
# whether the terminal is UTF-8 guesses ASCII, so saying so matters.
if [ -f /etc/locale.conf ]; then
. /etc/locale.conf
fi
: ${LANG:=C.UTF-8}
export LANG
if [ -f /etc/kshrc ]; then
. /etc/kshrc
fi

19
etc/schinit/keymap.job Normal file
View file

@ -0,0 +1,19 @@
# Apply the console keyboard layout named in /etc/vconsole.conf.
#
# RunAtLoad with no KeepAlive: it reads one line, sets one thing and exits. A
# job that has finished is not a job that failed.
#
# Ordering does not matter. The kernel starts on the built-in default, so
# there is no window in which the keyboard does not work -- this only changes
# which keys produce which characters, and it lands long before anyone can
# type. If the file is missing or names a layout the kernel does not have,
# loadkeys says so and the default stands.
Label = os.schos.keymap
Program = /bin/loadkeys
Args = loadkeys -c
RunAtLoad = yes
KeepAlive = no
StandardOut = /dev/tty1
StandardError = /dev/tty1

14
etc/vconsole.conf Normal file
View file

@ -0,0 +1,14 @@
# /etc/vconsole.conf — the console keyboard layout.
#
# Applied at boot by the os.schos.keymap job, and by `loadkeys -c` at any time
# after. `loadkeys -l` lists what the kernel has; `loadkeys <name>` switches
# for this session without touching this file.
#
# us English (US), QWERTY
# pl Polish (programmers) -- US QWERTY with the diacritics on AltGr
# de German, QWERTZ
#
# The layouts are in the kernel rather than in files here, so a machine with
# nothing mounted still has a working keyboard. This file only names one.
KEYMAP=us

12
etc/zsh/zshenv
View file

@ -7,7 +7,17 @@
: ${TERM:=linux}
: ${HOME:=/root}
: ${PATH:=/bin:/usr/bin}
export TERM HOME PATH
# UTF-8, said out loud. zsh's line editor handles multibyte input either way --
# musl decodes UTF-8 whatever the locale claims -- but everything that branches
# on $LANG to decide whether it may print a non-ASCII character needs this set,
# and an unset LANG reads as "ASCII only".
if [ -f /etc/locale.conf ]; then
. /etc/locale.conf
fi
: ${LANG:=C.UTF-8}
export TERM HOME PATH LANG
# Where zsh's own functions live. Set here rather than compiled in so a second
# version can be installed beside this one without either moving.

137
include/kbd.h
View file

@ -1,4 +1,12 @@
// PC keyboard interface constants
//
// The scancode tables themselves are no longer here. They moved to
// kernel/dev/keymap.c when there became more than one of them -- a header
// full of `static` arrays gives every file that includes it its own private
// copy, which was harmless while exactly one file did.
#ifndef KBD_H
#define KBD_H
#define KBSTATP 0x64 // kbd controller status port(I)
#define KBS_DIB 0x01 // kbd data in buffer
@ -24,25 +32,36 @@
// Nothing the kernel binds may involve it.
#define RALT (1<<7)
// Special keycodes
#define KEY_HOME 0xE0
#define KEY_END 0xE1
#define KEY_UP 0xE2
#define KEY_DN 0xE3
#define KEY_LF 0xE4
#define KEY_RT 0xE5
#define KEY_PGUP 0xE6
#define KEY_PGDN 0xE7
#define KEY_INS 0xE8
#define KEY_DEL 0xE9
// Special keycodes.
//
// **Above every Unicode codepoint, deliberately**, and they did not use to be:
// KBD_UP was 0xE2 and its neighbours filled 0xE0..0xE9. Those are exactly the
// UTF-8 lead bytes for three-byte characters, so typing any of U+0800..U+FFFF
// -- which is most punctuation, every arrow, every maths symbol, and the whole
// of CJK -- produced a keycode the console read as an arrow key and turned
// into `ESC [ A`. `∞`, `→`, `≤` and `'` all vanished from the input line while
// `ą` and `ę` came through, because those are two-byte sequences whose lead
// byte is 0xC4 and nothing claimed 0xC4.
//
// The chord codes below already knew this rule and said so; the navigation
// keys predate them and were never brought in line. The rule, stated once: a
// value that a key produces is either a Unicode codepoint or it is above
// 0x10FFFF, and nothing in between means anything.
#define KBD_SPECIAL 0x110000
#define KBD_HOME (KBD_SPECIAL + 0x00)
#define KBD_END (KBD_SPECIAL + 0x01)
#define KBD_UP (KBD_SPECIAL + 0x02)
#define KBD_DN (KBD_SPECIAL + 0x03)
#define KBD_LF (KBD_SPECIAL + 0x04)
#define KBD_RT (KBD_SPECIAL + 0x05)
#define KBD_PGUP (KBD_SPECIAL + 0x06)
#define KBD_PGDN (KBD_SPECIAL + 0x07)
#define KBD_INS (KBD_SPECIAL + 0x08)
#define KBD_DEL (KBD_SPECIAL + 0x09)
// Switch virtual terminal.
//
// Above 0xFF deliberately. kbdgetc returns an int and consoleintr takes one,
// and every value that fits in a byte is already either a character or a
// UTF-8 continuation byte. A chord that collided with one would be typed into
// the terminal instead of switching away from it.
//
// *Which* chord is a runtime setting, not a constant here, and that is the
// interesting part. Three separate parties have a claim on every candidate:
//
@ -76,13 +95,13 @@
// and no application asks for it. Right Alt being a separate modifier bit
// here is what makes the distinction expressible at all -- it used to share
// ALT, which is harmless for typing and useless for this.
#define KEY_VT_SWITCH 0x120
#define KBD_VT_SWITCH (KBD_SPECIAL + 0x20)
// Previous / next terminal, on the same modifiers as the chord above. The
// minus and equals keys, which sit together and read as - and + -- a relative
// move for when you have two terminals and do not care which number they are.
#define KEY_VT_PREV 0x130
#define KEY_VT_NEXT 0x131
#define KBD_VT_PREV (KBD_SPECIAL + 0x30)
#define KBD_VT_NEXT (KBD_SPECIAL + 0x31)
#define SCAN_MINUS 0x0C // - / _
#define SCAN_EQUALS 0x0D // = / +
@ -93,82 +112,4 @@
// C('A') == Control-A
#define C(x) (x - '@')
static uchar shiftcode[256] =
{
[0x1D] CTL,
[0x2A] SHIFT,
[0x36] SHIFT,
[0x38] ALT,
[0x9D] CTL,
[0xB8] RALT // right Alt / AltGr -- see RALT above
};
static uchar togglecode[256] =
{
[0x3A] CAPSLOCK,
[0x45] NUMLOCK,
[0x46] SCROLLLOCK
};
static uchar normalmap[256] =
{
NO, 0x1B, '1', '2', '3', '4', '5', '6', // 0x00
'7', '8', '9', '0', '-', '=', '\b', '\t',
'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', // 0x10
'o', 'p', '[', ']', '\n', NO, 'a', 's',
'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', // 0x20
'\'', '`', NO, '\\', 'z', 'x', 'c', 'v',
'b', 'n', 'm', ',', '.', '/', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', '.', NO, NO, NO, NO, // 0x50
[0x9C] '\n', // KP_Enter
[0xB5] '/', // KP_Div
[0xC8] KEY_UP, [0xD0] KEY_DN,
[0xC9] KEY_PGUP, [0xD1] KEY_PGDN,
[0xCB] KEY_LF, [0xCD] KEY_RT,
[0x97] KEY_HOME, [0xCF] KEY_END,
[0xD2] KEY_INS, [0xD3] KEY_DEL
};
static uchar shiftmap[256] =
{
NO, 033, '!', '@', '#', '$', '%', '^', // 0x00
'&', '*', '(', ')', '_', '+', '\b', '\t',
'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', // 0x10
'O', 'P', '{', '}', '\n', NO, 'A', 'S',
'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', // 0x20
'"', '~', NO, '|', 'Z', 'X', 'C', 'V',
'B', 'N', 'M', '<', '>', '?', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', '.', NO, NO, NO, NO, // 0x50
[0x9C] '\n', // KP_Enter
[0xB5] '/', // KP_Div
[0xC8] KEY_UP, [0xD0] KEY_DN,
[0xC9] KEY_PGUP, [0xD1] KEY_PGDN,
[0xCB] KEY_LF, [0xCD] KEY_RT,
[0x97] KEY_HOME, [0xCF] KEY_END,
[0xD2] KEY_INS, [0xD3] KEY_DEL
};
static uchar ctlmap[256] =
{
NO, NO, NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, NO,
C('Q'), C('W'), C('E'), C('R'), C('T'), C('Y'), C('U'), C('I'),
C('O'), C('P'), NO, NO, '\r', NO, C('A'), C('S'),
C('D'), C('F'), C('G'), C('H'), C('J'), C('K'), C('L'), NO,
NO, NO, NO, C('\\'), C('Z'), C('X'), C('C'), C('V'),
C('B'), C('N'), C('M'), NO, NO, C('/'), NO, NO,
[0x9C] '\r', // KP_Enter
[0xB5] C('/'), // KP_Div
[0xC8] KEY_UP, [0xD0] KEY_DN,
[0xC9] KEY_PGUP, [0xD1] KEY_PGDN,
[0xCB] KEY_LF, [0xCD] KEY_RT,
[0x97] KEY_HOME, [0xCF] KEY_END,
[0xD2] KEY_INS, [0xD3] KEY_DEL
};
#endif /* KBD_H */

50
include/keymap.h Normal file
View file

@ -0,0 +1,50 @@
// Keyboard layouts.
//
// A layout answers one question: given a scancode and the modifiers held,
// which Unicode codepoint was typed? Everything else about the keyboard --
// which port to read, when a key is a release, what the terminal-switch chord
// is -- belongs to kernel/dev/kbd.c and is the same whatever the layout.
//
// Codepoints, not bytes. A layout that can only produce bytes can produce
// `ó` (U+00F3, which fits in Latin-1) but not `ą` (U+0105, which does not),
// and half a Polish alphabet is not a Polish layout. kbd.c encodes the
// codepoint to UTF-8 on the way to the console.
//
// **No dead keys.** On a German layout the acute and circumflex keys are dead
// -- pressed, they wait for the next key and combine -- and here they simply
// produce the accent character on its own. That is wrong, it is visibly
// wrong, and it needs somewhere to hold "a dead key is pending", which is
// per-keyboard state this interface has no room for. Layouts that need it are
// not shipped rather than shipped broken; see keymap_layouts[] for which.
#ifndef KEYMAP_H
#define KEYMAP_H
#include "types.h"
// Which of a layout's four tables a set of modifiers selects. Plain, Shift,
// AltGr, and Shift+AltGr -- Ctrl is not one of them, because a control
// character is derived from the plain codepoint rather than looked up, which
// is what makes Ctrl+Z still be Ctrl+Z on a layout that moved the Z key.
#define KM_PLAIN 0
#define KM_SHIFT 1
#define KM_ALTGR 2
#define KM_SHIFTALTGR 3
#define KM_LEVELS 4
struct keylayout {
const char *name; // "us", "pl", "de" -- what you type
const char *desc; // what it is, for `loadkeys -l`
const uint32 *level[KM_LEVELS]; // 256 entries each; NULL falls back
};
// The active layout, and the catalogue.
const struct keylayout *keymap_active(void);
const struct keylayout *keymap_by_index(int i); // NULL past the end
int keymap_set(const char *name); // 0, or -1 if unknown
// Scancode plus modifier bits (SHIFT/CTL/ALT/RALT/CAPSLOCK from kbd.h) to a
// Unicode codepoint, or one of the KBD_* specials, or 0 for "no character".
uint32 keymap_lookup(uint scancode, uint mods);
#endif /* KEYMAP_H */

16
include/posix.h
View file

@ -163,6 +163,22 @@ struct rlimit {
#define VT_GETCHORD 0x5620
#define VT_SETCHORD 0x5621
// KB_GETLAYOUT / KB_SETLAYOUT / KB_LISTLAYOUT -- which keyboard layout the
// console uses. SchOS's own, and deliberately not Linux's KDGKBENT: that
// interface hands over one key of one table at a time and expects userspace to
// own the whole map, which means a `loadkeys` that ships its own data files and
// a boot that is broken until one is loaded. The layouts live in the kernel
// here, and userspace names the one it wants.
#define KB_GETLAYOUT 0x5622 // fill in the active layout
#define KB_SETLAYOUT 0x5623 // switch to the layout named in `name`
#define KB_LISTLAYOUT 0x5624 // describe layout `index`; -EINVAL past end
struct kb_layout {
uint16 index; // in for KB_LISTLAYOUT, out for KB_GETLAYOUT
char name[16]; // "us", "pl", "de"
char desc[96]; // human-readable, for `loadkeys -l`
};
// Modifier bits, matched exactly. These mirror kernel/dev/kbd.h's values so
// that userspace and the keyboard driver cannot drift apart.
#define VTC_SHIFT 0x01 // kbd.h SHIFT (1<<0)

70
kernel/core/console.c
View file

@ -4,7 +4,7 @@
#include "klog.h"
#include "dbg.h"
#include "vt.h"
#include "kbd.h" /* KEY_VT_SWITCH -- the terminal-switch chords */
#include "kbd.h" /* KBD_VT_SWITCH -- the terminal-switch chords */
#include "gfx.h"
#include "theme.h"
#include "irq.h"
@ -434,14 +434,14 @@ erase_one(struct vt *v)
// ---------------------------------------------------------------------------
// Ctrl+Alt+Shift+F1..F6 switch terminals. kbd.c reports them as
// KEY_VT_SWITCH+n so that the
// KBD_VT_SWITCH+n so that the
// decision of what a chord *means* is made here, where the terminals are,
// rather than in a driver that should not know they exist.
int
console_vt_hotkey(int key)
{
if (key != KEY_VT_PREV && key != KEY_VT_NEXT &&
(key < KEY_VT_SWITCH || key >= KEY_VT_SWITCH + NVT))
if (key != KBD_VT_PREV && key != KBD_VT_NEXT &&
(key < KBD_VT_SWITCH || key >= KBD_VT_SWITCH + NVT))
return 0;
// A program that called VT_SETMODE(VT_PROCESS) owns switching on this
// terminal. Dropping the chord entirely would be worse than not binding it:
@ -449,9 +449,9 @@ console_vt_hotkey(int key)
// falls through to the line discipline as an ordinary key.
if (!vt_kernel_switches())
return 0;
if (key == KEY_VT_PREV) vt_cycle(-1);
else if (key == KEY_VT_NEXT) vt_cycle(+1);
else vt_switch(key - KEY_VT_SWITCH);
if (key == KBD_VT_PREV) vt_cycle(-1);
else if (key == KBD_VT_NEXT) vt_cycle(+1);
else vt_switch(key - KBD_VT_SWITCH);
return 1;
}
@ -467,8 +467,8 @@ consoleintr(int (*getc)(void))
// Terminal switching happens before the line discipline sees anything:
// the chord is not input for the terminal you are leaving.
if (c == KEY_VT_PREV || c == KEY_VT_NEXT ||
(c >= KEY_VT_SWITCH && c < KEY_VT_SWITCH + NVT)) {
if (c == KBD_VT_PREV || c == KBD_VT_NEXT ||
(c >= KBD_VT_SWITCH && c < KBD_VT_SWITCH + NVT)) {
release(&input_lock);
int taken = console_vt_hotkey(c);
acquire(&input_lock);
@ -481,8 +481,10 @@ consoleintr(int (*getc)(void))
// terminal a terminal: the keyboard follows the eyes.
struct vt *v = vt_current();
// Input mapping, before anything looks at the character.
if (v->tio.c_iflag & ISTRIP) c &= 0x7f;
// Input mapping, before anything looks at the character. ISTRIP is about
// seven-bit lines and applies to characters only -- masking a keycode
// would turn an arrow key into whatever letter its low seven bits spell.
if ((v->tio.c_iflag & ISTRIP) && c < KBD_SPECIAL) c &= 0x7f;
if (c == '\r') {
if (v->tio.c_iflag & IGNCR) continue;
if (v->tio.c_iflag & ICRNL) c = '\n';
@ -567,12 +569,13 @@ consoleintr(int (*getc)(void))
// Arrow keys and the rest of the navigation block, as escape sequences.
//
// These arrive as single keycodes -- KEY_UP is 0xE2 -- and used to be
// pushed into the input buffer exactly like that. A terminal has never
// worked that way, and 0xE2 in particular is the worst possible choice of
// byte: it is a UTF-8 lead byte for a three-byte character, so a reader
// decoding UTF-8 swallowed the next two keys waiting for continuations
// that never came. Every arrow key corrupted the two keystrokes after it.
// These arrive as single keycodes and used to be pushed into the input
// buffer exactly like that. A terminal has never worked that way, and the
// values chosen made it worse: KBD_UP was 0xE2, a UTF-8 lead byte for a
// three-byte character, so a reader decoding UTF-8 swallowed the next two
// keys waiting for continuations that never came -- every arrow key
// corrupted the two keystrokes after it. The keycodes now sit above
// U+10FFFF where nothing can collide with them; see include/kbd.h.
//
// What a terminal sends is `ESC [ A`, and what makes zsh's line editor
// work is receiving that. The sequences below are the DEC/xterm ones that
@ -580,16 +583,16 @@ consoleintr(int (*getc)(void))
{
const char *esc = 0;
switch (c) {
case KEY_UP: esc = "\033[A"; break;
case KEY_DN: esc = "\033[B"; break;
case KEY_RT: esc = "\033[C"; break;
case KEY_LF: esc = "\033[D"; break;
case KEY_HOME: esc = "\033[H"; break;
case KEY_END: esc = "\033[F"; break;
case KEY_PGUP: esc = "\033[5~"; break;
case KEY_PGDN: esc = "\033[6~"; break;
case KEY_INS: esc = "\033[2~"; break;
case KEY_DEL: esc = "\033[3~"; break;
case KBD_UP: esc = "\033[A"; break;
case KBD_DN: esc = "\033[B"; break;
case KBD_RT: esc = "\033[C"; break;
case KBD_LF: esc = "\033[D"; break;
case KBD_HOME: esc = "\033[H"; break;
case KBD_END: esc = "\033[F"; break;
case KBD_PGUP: esc = "\033[5~"; break;
case KBD_PGDN: esc = "\033[6~"; break;
case KBD_INS: esc = "\033[2~"; break;
case KBD_DEL: esc = "\033[3~"; break;
}
if (esc) {
// Not echoed. In raw mode -- which is where a line editor lives, and
@ -610,12 +613,19 @@ consoleintr(int (*getc)(void))
}
}
// Any keycode still here is a special nobody translated. Dropping it is
// the only safe thing: storing it would truncate to a byte and type a
// character the user did not press.
if (c >= KBD_SPECIAL)
continue;
if (v->in.e - v->in.r >= VT_INPUT_BUF)
continue; // buffer full: drop it
// Everything else goes in, including bytes above 127 -- those are UTF-8
// continuation bytes, and the old `c >= 32 && c <= 126` test silently
// refused every non-ASCII character anyone tried to type.
// Everything else goes in, including bytes above 127 -- those are UTF-8,
// arriving a byte at a time from the serial line or encoded by kbdgetc,
// and the old `c >= 32 && c <= 126` test silently refused every non-ASCII
// character anyone tried to type.
v->in.buf[v->in.e++ % VT_INPUT_BUF] = c;
echo(v, c);

95
kernel/dev/kbd.c
View file

@ -5,6 +5,7 @@
#include "posix.h"
#include "vt.h" /* NVT -- how many terminals the chords reach */
#include "input.h"
#include "keymap.h"
// The chord, settable at run time through VT_SETCHORD.
//
@ -21,14 +22,72 @@
uint vt_chord_mods = RALT;
uint vt_chord_base = SCAN_F1;
// Which scancodes are modifiers, and which are locks. Hardware facts rather
// than layout ones -- every layout agrees that 0x2A is a Shift key -- so they
// stay here while the character tables live in keymap.c.
static const uchar shiftcode[256] = {
[0x1D] = CTL,
[0x2A] = SHIFT,
[0x36] = SHIFT,
[0x38] = ALT,
[0x9D] = CTL,
[0xB8] = RALT // right Alt / AltGr -- see RALT in kbd.h
};
static const uchar togglecode[256] = {
[0x3A] = CAPSLOCK,
[0x45] = NUMLOCK,
[0x46] = SCROLLLOCK
};
// A key can produce more than one byte.
//
// consoleintr's contract with getc() is bytes: the serial line hands it raw
// UTF-8 already, and it would have no way to tell an encoded codepoint apart
// from a byte that happened to have the same value. So the keyboard encodes
// here and hands the bytes over one call at a time -- kbdintr loops until
// getc() returns negative, so a queue of at most four drains on its own
// before the next scancode is read.
static uchar pend[4];
static int pend_n, pend_i;
static int
queue_utf8(uint32 cp)
{
pend_i = 0;
if (cp < 0x80) {
pend_n = 0;
return (int)cp; // the common case: no queue at all
}
if (cp < 0x800) {
pend[0] = 0xC0 | (cp >> 6);
pend[1] = 0x80 | (cp & 0x3F);
pend_n = 2;
} else if (cp < 0x10000) {
pend[0] = 0xE0 | (cp >> 12);
pend[1] = 0x80 | ((cp >> 6) & 0x3F);
pend[2] = 0x80 | (cp & 0x3F);
pend_n = 3;
} else {
pend[0] = 0xF0 | (cp >> 18);
pend[1] = 0x80 | ((cp >> 12) & 0x3F);
pend[2] = 0x80 | ((cp >> 6) & 0x3F);
pend[3] = 0x80 | (cp & 0x3F);
pend_n = 4;
}
return pend[pend_i++];
}
int
kbdgetc(void)
{
static uint shift;
static uchar *charcode[4] = {
normalmap, shiftmap, ctlmap, ctlmap
};
uint st, data, c;
uint st, data;
uint32 cp;
if (pend_i < pend_n)
return pend[pend_i++]; // finish the last key first
pend_i = pend_n = 0;
st = inb(KBSTATP);
if((st & KBS_DIB) == 0)
@ -81,29 +140,25 @@ kbdgetc(void)
// terminal". What it means is decided in console.c, which is where the
// terminals are; this only has to name it. See console_vt_hotkey().
//
// The modifier test is an equality, not a mask. A mask fires on any superset,
// so a chord aimed at the host would switch terminals behind your back.
//
// The modifier test is an equality, not a mask. `shift & ALT` would fire on
// Ctrl+Alt+1 and on AltGr+1 as well, so a chord aimed at the host -- or a
// Polish keystroke -- would switch terminals behind your back. Exactly left
// Alt, and nothing else held.
// Polish keystroke -- would switch terminals behind your back. Exactly the
// modifiers named, and nothing else held.
if (vt_chord_mods != 0 &&
(shift & (CTL | SHIFT | ALT | RALT)) == vt_chord_mods) {
if (data >= vt_chord_base && data < vt_chord_base + NVT)
return KEY_VT_SWITCH + (data - vt_chord_base);
if (data == SCAN_MINUS) return KEY_VT_PREV;
if (data == SCAN_EQUALS) return KEY_VT_NEXT;
return KBD_VT_SWITCH + (data - vt_chord_base);
if (data == SCAN_MINUS) return KBD_VT_PREV;
if (data == SCAN_EQUALS) return KBD_VT_NEXT;
}
c = charcode[shift & (CTL | SHIFT)][data];
if(shift & CAPSLOCK){
if('a' <= c && c <= 'z')
c += 'A' - 'a';
else if('A' <= c && c <= 'Z')
c += 'a' - 'A';
}
return c;
cp = keymap_lookup(data, shift);
if (cp == 0)
return 0;
if (cp >= KBD_SPECIAL)
return (int)cp; // arrows and the rest, not characters
return queue_utf8(cp);
}
void

297
kernel/dev/keymap.c Normal file
View file

@ -0,0 +1,297 @@
// Keyboard layouts. See include/keymap.h for the interface and its limits.
//
// Every table is indexed by set-1 scancode, with the E0-prefixed keys folded
// into 0x80..0xFF by kbd.c before the lookup -- the same numbering the single
// hardcoded table used, so a layout is a diff against a shape that was already
// proven to work rather than a new mapping to get wrong.
//
// The tables are `uint32` and not `uchar`. That is the whole reason this file
// exists: `ą` is U+0105 and does not fit in a byte, and a Polish layout that
// cannot type `ą` is not one.
#include "types.h"
#include "defs.h"
#include "kbd.h"
#include "keymap.h"
// Shared by every layout that does not move the navigation block, which is
// all of them -- the arrow keys are not a national matter. Merged into each
// level table below rather than consulted separately, because a layout is
// allowed to disagree and none currently does.
#define NAV_KEYS \
[0xC8] = KBD_UP, [0xD0] = KBD_DN, \
[0xC9] = KBD_PGUP, [0xD1] = KBD_PGDN, \
[0xCB] = KBD_LF, [0xCD] = KBD_RT, \
[0x97] = KBD_HOME, [0xCF] = KBD_END, \
[0xD2] = KBD_INS, [0xD3] = KBD_DEL, \
[0x9C] = '\n', /* KP_Enter */ \
[0xB5] = '/' /* KP_Div */
// --- US ---------------------------------------------------------------------
static const uint32 us_plain[256] = {
NO, 0x1B, '1', '2', '3', '4', '5', '6', // 0x00
'7', '8', '9', '0', '-', '=', '\b', '\t',
'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', // 0x10
'o', 'p', '[', ']', '\n', NO, 'a', 's',
'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', // 0x20
'\'', '`', NO, '\\', 'z', 'x', 'c', 'v',
'b', 'n', 'm', ',', '.', '/', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', '.', NO, NO, NO, NO, // 0x50
NAV_KEYS
};
static const uint32 us_shift[256] = {
NO, 0x1B, '!', '@', '#', '$', '%', '^', // 0x00
'&', '*', '(', ')', '_', '+', '\b', '\t',
'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', // 0x10
'O', 'P', '{', '}', '\n', NO, 'A', 'S',
'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', // 0x20
'"', '~', NO, '|', 'Z', 'X', 'C', 'V',
'B', 'N', 'M', '<', '>', '?', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', '.', NO, NO, NO, NO, // 0x50
NAV_KEYS
};
// --- Polish (programmers) ---------------------------------------------------
//
// US QWERTY with nine letters on AltGr. This is the layout essentially every
// Polish developer uses, and the reason is that the alternative -- "Polish
// (214)", a genuine national arrangement -- moves Y, Z and most of the
// punctuation, which makes every shell and every editor shortcut land
// somewhere else. The diacritics go on AltGr and nothing else moves.
//
// AltGr+x is ź and AltGr+z is ż, which looks arbitrary and is not: the letter
// x is unused in Polish, so its key is free, and ź and ż both need one.
static const uint32 pl_altgr[256] = {
[0x1E] = 0x0105, // a -> ą
[0x2E] = 0x0107, // c -> ć
[0x12] = 0x0119, // e -> ę
[0x26] = 0x0142, // l -> ł
[0x31] = 0x0144, // n -> ń
[0x18] = 0x00F3, // o -> ó
[0x1F] = 0x015B, // s -> ś
[0x2D] = 0x017A, // x -> ź
[0x2C] = 0x017C, // z -> ż
};
static const uint32 pl_shiftaltgr[256] = {
[0x1E] = 0x0104, // A -> Ą
[0x2E] = 0x0106, // C -> Ć
[0x12] = 0x0118, // E -> Ę
[0x26] = 0x0141, // L -> Ł
[0x31] = 0x0143, // N -> Ń
[0x18] = 0x00D3, // O -> Ó
[0x1F] = 0x015A, // S -> Ś
[0x2D] = 0x0179, // X -> Ź
[0x2C] = 0x017B, // Z -> Ż
};
// --- German (QWERTZ) --------------------------------------------------------
//
// Y and Z swap, the umlauts and ß take the punctuation keys on the home and
// top rows, and the key between left Shift and Z -- scancode 0x56, which a US
// keyboard does not have at all -- carries < > |.
//
// The acute (0x0D) and circumflex (0x29) keys are dead on a real German
// layout. Here they type the accent on its own. See include/keymap.h.
static const uint32 de_plain[256] = {
NO, 0x1B, '1', '2', '3', '4', '5', '6', // 0x00
'7', '8', '9', '0', 0x00DF, 0x00B4, '\b', '\t', // ß ´
'q', 'w', 'e', 'r', 't', 'z', 'u', 'i', // 0x10
'o', 'p', 0x00FC, '+', '\n', NO, 'a', 's', // ü
'd', 'f', 'g', 'h', 'j', 'k', 'l', 0x00F6, // ö
0x00E4, '^', NO, '#', 'y', 'x', 'c', 'v', // ä
'b', 'n', 'm', ',', '.', '-', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', ',', NO, NO, '<', NO, // 0x50, 0x56 = <>|
NAV_KEYS
};
static const uint32 de_shift[256] = {
NO, 0x1B, '!', '"', 0x00A7, '$', '%', '&', // 0x00 §
'/', '(', ')', '=', '?', '`', '\b', '\t',
'Q', 'W', 'E', 'R', 'T', 'Z', 'U', 'I', // 0x10
'O', 'P', 0x00DC, '*', '\n', NO, 'A', 'S', // Ü
'D', 'F', 'G', 'H', 'J', 'K', 'L', 0x00D6, // Ö
0x00C4, 0x00B0, NO, '\'', 'Y', 'X', 'C', 'V', // Ä °
'B', 'N', 'M', ';', ':', '_', NO, '*', // 0x30
NO, ' ', NO, NO, NO, NO, NO, NO,
NO, NO, NO, NO, NO, NO, NO, '7', // 0x40
'8', '9', '-', '4', '5', '6', '+', '1',
'2', '3', '0', ',', NO, NO, '>', NO, // 0x50
NAV_KEYS
};
static const uint32 de_altgr[256] = {
[0x03] = 0x00B2, // 2 -> ²
[0x04] = 0x00B3, // 3 -> ³
[0x08] = '{', // 7
[0x09] = '[', // 8
[0x0A] = ']', // 9
[0x0B] = '}', // 0
[0x0C] = '\\', // ß
[0x10] = '@', // q
[0x12] = 0x20AC, // e -> €
[0x1B] = '~', // +
[0x32] = 0x00B5, // m -> µ
[0x56] = '|',
};
// --- the catalogue ----------------------------------------------------------
//
// Order matters only in that the first entry is the default. US, because a
// machine whose keyboard layout has never been set should behave the way the
// scancodes are printed on the majority of keyboards, and because every
// installation instruction anyone follows is written in ASCII.
static const struct keylayout layouts[] = {
{ "us", "English (US), QWERTY",
{ us_plain, us_shift, 0, 0 } },
{ "pl", "Polish (programmers) -- US QWERTY, diacritics on AltGr",
{ us_plain, us_shift, pl_altgr, pl_shiftaltgr } },
{ "de", "German, QWERTZ -- no dead keys, so the accent keys type the accent",
{ de_plain, de_shift, de_altgr, 0 } },
};
#define NLAYOUTS ((int)(sizeof(layouts) / sizeof(layouts[0])))
static const struct keylayout *active = &layouts[0];
const struct keylayout *
keymap_active(void)
{
return active;
}
const struct keylayout *
keymap_by_index(int i)
{
if (i < 0 || i >= NLAYOUTS)
return 0;
return &layouts[i];
}
int
keymap_set(const char *name)
{
for (int i = 0; i < NLAYOUTS; i++) {
const char *a = layouts[i].name, *b = name;
while (*a && *a == *b) { a++; b++; }
if (*a == 0 && *b == 0) {
active = &layouts[i];
return 0;
}
}
return -1;
}
// A control character from the plain codepoint rather than from a table of
// its own.
//
// The table this replaces was indexed by scancode, which quietly assumed a US
// keyboard: on QWERTZ, Ctrl+Z and Ctrl+Y would have swapped with the letters,
// so suspending a job would have depended on the layout. Deriving from what
// the key actually types is both shorter and correct everywhere.
static uint32
control_of(uint32 cp)
{
if (cp >= 'a' && cp <= 'z') return cp - 'a' + 1;
if (cp >= 'A' && cp <= 'Z') return cp - 'A' + 1;
switch (cp) {
case '@': case ' ': case '2': return 0; // NUL
case '[': return 0x1B; // ESC
case '\\': return 0x1C;
case ']': return 0x1D;
case '^': case '6': return 0x1E;
case '_': case '-': case '/': return 0x1F;
case '?': return 0x7F;
case '\n': case '\r': return '\r';
}
return 0; // no control character on this key
}
// Upper <-> lower for the letters these layouts can produce.
//
// Caps Lock needs this and Shift does not: Shift has its own table, so the
// layout has already said what the shifted key gives. Caps Lock has no table
// -- it applies to whatever came out, including `ą` from the AltGr level --
// so the case pair has to be derived from the codepoint.
//
// Latin Extended-A is laid out in alternating pairs, but not all the same way
// round: U+0100..U+0137 and U+014A..U+0177 have the capital on the even
// codepoint, while U+0139..U+0148 and U+0179..U+017E have it on the odd one.
// L-stroke is U+0141/U+0142 and Z-dot is U+017B/U+017C, so Polish lands in
// both halves and getting the parity wrong would shift one of them to a
// neighbouring letter rather than to its own capital.
static uint32
case_toggle(uint32 cp)
{
if (cp >= 'a' && cp <= 'z') return cp - 'a' + 'A';
if (cp >= 'A' && cp <= 'Z') return cp - 'A' + 'a';
// Latin-1: the accented letters run C0..DE and E0..FE, with multiplication
// and division signs punched out of the middle of each. Eszett (DF) has no
// single-codepoint capital and stays as it is.
if (cp >= 0xC0 && cp <= 0xDE && cp != 0xD7) return cp + 0x20;
if (cp >= 0xE0 && cp <= 0xFE && cp != 0xF7) return cp - 0x20;
if ((cp >= 0x0100 && cp <= 0x0137) || (cp >= 0x014A && cp <= 0x0177))
return (cp & 1) ? cp - 1 : cp + 1; // even is the capital
if ((cp >= 0x0139 && cp <= 0x0148) || (cp >= 0x0179 && cp <= 0x017E))
return (cp & 1) ? cp + 1 : cp - 1; // odd is the capital
return cp;
}
uint32
keymap_lookup(uint scancode, uint mods)
{
const struct keylayout *l = active;
uint32 cp;
if (scancode > 0xFF)
return 0;
// AltGr first. It is the only modifier that selects a whole different table,
// and on a layout that has no AltGr level the lookup falls back rather than
// producing nothing -- otherwise holding AltGr on a US keyboard would make
// every key dead.
int level = KM_PLAIN;
if (mods & RALT) level = (mods & SHIFT) ? KM_SHIFTALTGR : KM_ALTGR;
else if (mods & SHIFT) level = KM_SHIFT;
cp = l->level[level] ? l->level[level][scancode] : 0;
if (cp == 0 && level >= KM_ALTGR) {
level = (mods & SHIFT) ? KM_SHIFT : KM_PLAIN;
cp = l->level[level] ? l->level[level][scancode] : 0;
}
if (cp == 0)
return 0;
// Caps Lock is a letter-case toggle, not a Shift: it applies to whatever
// the table produced, including a letter that only exists on AltGr. `ą`
// with Caps Lock on is `Ą`, and only the layout knows that -- so the case
// pair has to come from the codepoint, not from a second table lookup.
if ((mods & CAPSLOCK) && cp < KBD_SPECIAL)
cp = case_toggle(cp);
// Ctrl is last and overrides: Ctrl+Shift+C is still Ctrl+C.
if (mods & CTL) {
if (cp >= KBD_SPECIAL)
return cp; // Ctrl+arrow stays an arrow
return control_of(cp);
}
return cp;
}

187
kernel/sys/sys_fs.c
View file

@ -18,6 +18,7 @@
#include "gfx.h" /* gfx_cols/gfx_rows — TIOCGWINSZ reports them */
#include "vt.h" /* the terminals TIOC*/VT_* act on */
#include "pciuser.h"
#include "keymap.h" /* KB_*LAYOUT — the keyboard layout catalogue */
#include "netuser.h"
// -----------------------------------------------------------------------
@ -459,6 +460,35 @@ addr_t sys_pipe2(void)
// Filesystem ops
// -----------------------------------------------------------------------
// Resolve a symlink opened as the final path component.
//
// divesymlink() has been in kernel/fs/fs.c since the fork and nothing ever
// called it, so a symlink behaved as a small file containing its own target:
// `cat link` printed the target's *name* rather than its contents, and every
// program that follows a symlink to find something followed it nowhere.
//
// Only the last component. A symlink in the middle of a path -- /a/link/b --
// is still not resolved; that belongs in namex(), which would have to re-enter
// path lookup while holding a directory lock, and getting that wrong is a
// deadlock rather than a wrong answer. Final-component resolution is what
// open(), exec() and stat() need, which is nearly everything that matters.
//
// Takes a locked inode and returns a locked inode, or 0 with everything
// released -- the same contract divesymlink() already had.
static struct inode *
follow_final(struct inode *ip, int omode)
{
if (ip->type != T_SYMLINK)
return ip;
if (omode & O_NOFOLLOW) {
// POSIX: opening a symlink itself is an error unless O_PATH, which
// this kernel does not have. Saying so beats handing back the link.
iunlockput(ip);
return 0;
}
return divesymlink(ip);
}
addr_t sys_open(void)
{
char *path;
@ -486,6 +516,7 @@ addr_t sys_open(void)
} else {
if (!(ip = namei(path))) { end_op(); return -ENOENT; }
ilock(ip);
if (!(ip = follow_final(ip, omode))) { end_op(); return -ELOOP; }
// Directories may only be opened for reading, but callers (e.g.
// opendir()) legitimately OR in flags like O_DIRECTORY/O_CLOEXEC/
// O_NONBLOCK alongside O_RDONLY — only the access-mode bits matter.
@ -530,6 +561,7 @@ addr_t sys_openat(void)
} else {
if (!(ip = at_namei(dirfd, path))) { end_op(); return -ENOENT; }
ilock(ip);
if (!(ip = follow_final(ip, omode))) { end_op(); return -ELOOP; }
// Directories may only be opened for reading, but callers (e.g.
// opendir()) legitimately OR in flags like O_DIRECTORY/O_CLOEXEC/
// O_NONBLOCK alongside O_RDONLY — only the access-mode bits matter.
@ -572,16 +604,21 @@ addr_t sys_fstat(void)
return 0;
}
addr_t sys_stat(void)
// stat/lstat differ in exactly one thing: whether a final symlink is followed.
// They used to be the same function, which was invisible while nothing
// followed symlinks anywhere and becomes wrong the moment something does.
static addr_t
do_stat(int dirfd, char *path, char *st, int follow)
{
char *path;
char *st;
struct inode *ip;
int size = myproc()->syscall_map ? sizeof(struct linux_stat) : sizeof(struct stat);
if (argstr(0, &path) < 0 || argptr(1, &st, size) < 0) return -1;
begin_op();
if (!(ip = namei(path))) { end_op(); return -ENOENT; }
if (!(ip = at_namei(dirfd, path))) { end_op(); return -ENOENT; }
ilock(ip);
if (follow && ip->type == T_SYMLINK && !(ip = divesymlink(ip))) {
end_op();
return -ELOOP;
}
if (myproc()->syscall_map) stati_linux(ip, (struct linux_stat*)st);
else stati(ip, (struct stat*)st);
iunlockput(ip);
@ -589,7 +626,23 @@ addr_t sys_stat(void)
return 0;
}
addr_t sys_lstat(void) { return sys_stat(); }
addr_t sys_stat(void)
{
char *path, *st;
int size = myproc()->syscall_map ? sizeof(struct linux_stat) : sizeof(struct stat);
if (argstr(0, &path) < 0) return -EFAULT;
if (argptr(1, &st, size) < 0) return -EFAULT;
return do_stat(AT_FDCWD, path, st, 1);
}
addr_t sys_lstat(void)
{
char *path, *st;
int size = myproc()->syscall_map ? sizeof(struct linux_stat) : sizeof(struct stat);
if (argstr(0, &path) < 0) return -EFAULT;
if (argptr(1, &st, size) < 0) return -EFAULT;
return do_stat(AT_FDCWD, path, st, 0);
}
addr_t sys_access(void)
{
@ -865,31 +918,71 @@ bad_rename:
ilock(ip); ip->nlink--; iupdate(ip); iunlockput(ip); end_op(); return -err;
}
// symlink(2).
//
// The errno matters more here than anywhere else in this file, because the one
// widespread use of symlink() is as an atomic lock: create a link, and if it
// already exists someone else holds the lock. zsh's history locking is exactly
// that, and it distinguishes EEXIST ("contended, wait and retry") from
// anything else ("this cannot work, give up"). Returning a bare -1 -- which is
// -EPERM -- put every zsh on the machine in the second bucket, and printed
//
// zsh: locking failed for /root/.zsh_history: operation not permitted
//
// on every boot, on a filesystem that supports symlinks perfectly well.
static addr_t
do_symlink(int newdirfd, char *target, char *linkpath)
{
struct inode *ip;
int len;
if (*target == 0)
return -ENOENT; // an empty target resolves to nothing
begin_op();
// Distinguishing the two ways createat() returns 0 -- the name is taken,
// or the path to it does not exist -- has to be done before the create,
// because createat() does not say which.
if ((ip = at_namei(newdirfd, linkpath)) != 0) {
iput(ip);
end_op();
return -EEXIST;
}
if (!(ip = createat(newdirfd, linkpath, T_SYMLINK, 0, 0))) {
end_op();
return -ENOENT;
}
len = strlen(target);
if (writei(ip, 0, (uint64)target, 0, len) != len) {
iunlockput(ip);
end_op();
return -EIO;
}
iunlockput(ip);
end_op();
return 0;
}
addr_t sys_symlink(void)
{
char *target, *linkpath;
if (argstr(0, &target) < 0 || argstr(1, &linkpath) < 0) return -1;
begin_op();
struct inode *ip = create(linkpath, T_SYMLINK, 0, 0);
if (!ip) { end_op(); return -1; }
int len = strlen(target);
if (writei(ip, 0, (uint64)target, 0, len) != len) { iunlockput(ip); end_op(); return -1; }
iunlockput(ip); end_op();
return 0;
if (argstr(0, &target) < 0 || argstr(1, &linkpath) < 0) return -EFAULT;
return do_symlink(AT_FDCWD, target, linkpath);
}
addr_t sys_readlink(void)
{
char *path, *buf;
int bufsiz;
if (argstr(0, &path) < 0 || argint(2, &bufsiz) < 0 || bufsiz <= 0) return -1;
if (argptr(1, &buf, bufsiz) < 0) return -1;
if (argstr(0, &path) < 0) return -EFAULT;
if (argint(2, &bufsiz) < 0 || bufsiz <= 0) return -EINVAL;
if (argptr(1, &buf, bufsiz) < 0) return -EFAULT;
struct inode *ip;
if (!(ip = namei(path))) return -ENOENT;
ilock(ip);
if (ip->type != T_SYMLINK) { iunlockput(ip); return -EINVAL; }
int n = (int)ip->size < bufsiz ? (int)ip->size : bufsiz;
if (readi(ip, 0, (uint64)buf, 0, n) != n) { iunlockput(ip); return -1; }
if (readi(ip, 0, (uint64)buf, 0, n) != n) { iunlockput(ip); return -EIO; }
iunlockput(ip);
return n;
}
@ -1255,6 +1348,32 @@ addr_t sys_ioctl(void)
return 0;
}
// Which keyboard layout the console uses. One layout for the machine, not
// one per terminal: there is one keyboard, and a user who switches to
// tty3 has not changed which keys their fingers are on.
if (request == KB_SETLAYOUT) {
struct kb_layout *k = (struct kb_layout*)user_ptr(argp, sizeof(*k));
if (!k) return -EFAULT;
k->name[sizeof(k->name) - 1] = 0;
if (keymap_set(k->name) < 0)
return -EINVAL;
return 0;
}
if (request == KB_GETLAYOUT || request == KB_LISTLAYOUT) {
struct kb_layout *k = (struct kb_layout*)user_ptr(argp, sizeof(*k));
if (!k) return -EFAULT;
const struct keylayout *l;
if (request == KB_GETLAYOUT) {
l = keymap_active();
} else {
l = keymap_by_index(k->index);
if (!l) return -EINVAL; // the documented end of the list
}
safestrcpy(k->name, l->name, sizeof(k->name));
safestrcpy(k->desc, l->desc, sizeof(k->desc));
return 0;
}
if (request == VT_GETMODE) {
struct vt_mode *m = (struct vt_mode*)user_ptr(argp, sizeof(*m));
if (!m) return -EFAULT;
@ -1596,18 +1715,10 @@ addr_t sys_symlinkat(void)
{
char *target, *linkpath;
int newdirfd;
if (argstr(0, &target) < 0) return -1;
if (argstr(0, &target) < 0) return -EFAULT;
argint(1, &newdirfd);
if (argstr(2, &linkpath) < 0) return -1;
begin_op();
struct inode *ip = createat(newdirfd, linkpath, T_SYMLINK, 0, 0);
if (!ip) { end_op(); return -1; }
int len = strlen(target);
if (writei(ip, 0, (uint64)target, 0, len) != len) {
iunlockput(ip); end_op(); return -1;
}
iunlockput(ip); end_op();
return 0;
if (argstr(2, &linkpath) < 0) return -EFAULT;
return do_symlink(newdirfd, target, linkpath);
}
addr_t sys_readlinkat(void)
@ -1616,15 +1727,15 @@ addr_t sys_readlinkat(void)
char *path, *buf;
int bufsiz;
argint(0, &dirfd);
if (argstr(1, &path) < 0) return -1;
if (argint(3, &bufsiz) < 0 || bufsiz <= 0) return -1;
if (argptr(2, &buf, bufsiz) < 0) return -1;
if (argstr(1, &path) < 0) return -EFAULT;
if (argint(3, &bufsiz) < 0 || bufsiz <= 0) return -EINVAL;
if (argptr(2, &buf, bufsiz) < 0) return -EFAULT;
struct inode *ip;
if (!(ip = at_namei(dirfd, path))) return -ENOENT;
ilock(ip);
if (ip->type != T_SYMLINK) { iunlockput(ip); return -EINVAL; }
int n = (int)ip->size < bufsiz ? (int)ip->size : bufsiz;
if (readi(ip, 0, (uint64)buf, 0, n) != n) { iunlockput(ip); return -1; }
if (readi(ip, 0, (uint64)buf, 0, n) != n) { iunlockput(ip); return -EIO; }
iunlockput(ip);
return n;
}
@ -1670,15 +1781,7 @@ addr_t sys_fstatat(void)
return 0;
}
begin_op();
struct inode *ip = at_namei(dirfd, path);
if (!ip) { end_op(); return -ENOENT; }
ilock(ip);
if (myproc()->syscall_map) stati_linux(ip, (struct linux_stat*)st);
else stati(ip, (struct stat*)st);
iunlockput(ip);
end_op();
return 0;
return do_stat(dirfd, path, st, !(flags & AT_SYMLINK_NOFOLLOW));
}
// -----------------------------------------------------------------------