baede13847
Milestone 1 of three: manifests, RunAtLoad, KeepAlive with throttling,
and reaping. Replaces the hardcoded fork-a-shell loop in cmd/init, which
stays in the tree for now.
Jobs are sectioned key=value files in /etc/schinit/*.job, kept in the
repo under etc/ and installed into the sysroot -- sysroot/ is generated
and gitignored, so anything written only there is lost on a fresh clone,
which is already true of /etc/passwd and should not become true of the
boot configuration. Unknown keys and sections are ignored rather than
fatal: a manifest written for a newer schinit must not stop this one
booting the machine.
Socket sections are parsed and recorded but not yet held. That is
milestone 2 and it is the whole reason for copying launchd rather than
sysvinit -- the supervisor holds the listener and starts the job on first
connect, which inverts the dependency graph and makes runlevels a
non-concept. The key exists now so manifests need not change later.
getdents64 is exposed to userland for this. The kernel has had it since
the Linux ABI landed, but nothing declared it in user.h or lib/usys.S, so
first-party programs had no way to list a directory at all.
Two things found by testing rather than reasoning:
- setsid() gives a job its own session, and a session has no
controlling terminal. The console then delivers input only to the
foreground process group it tracks, so the shell came up, echoed
every keystroke through the line discipline, and executed none of
them -- indistinguishable from a hung shell. ControllingTerminal=yes
claims it with TIOCSCTTY/TIOCSPGRP; off by default, since a daemon
has no business seizing the console.
- the first bootstrap() dropped /dev/input/event0-1 and most of /proc,
because it was transcribed from the part of the old init that had
been read rather than all of it. -Evdev caught it.
build/usbstick.img is built by `all` now: without it QEMU refuses the
-drive and the entire -Usb run produces no output, which reads as a
broken USB driver.
Seven suites green: base 27, Tty 51, Ps 32, Sock 64, Fb 36, Usb 31,
Evdev 29. make schfs-check passes.
3.6 KiB
| name | description | metadata | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| schunix-boot-splash-logo | The boot logo pipeline, why the loader draws it rather than the kernel, and the STAGE2_SECTORS trap that consolidating it exposed. |
|
The boot splash shows the Assets/Schunix Small Logo.png mark (an SX monogram in
a ring) above the S C H U N I X wordmark and its accent rule, all centred as
one group. Verified rendering correctly on 2026-08-08.
The logo is drawn by the bootloader, not the kernel. This is the
counter-intuitive part and it is a timing fact, not a preference: the kernel does
not reach vga_init() until roughly the last 300ms of a ~2.8s boot, so a
kernel-drawn logo appeared for about one frame before console_takeover() wiped
it. Drawn from splash() in boot/stage2main.c it is up for the whole boot.
kernel/dev/vga.c keeps the same drawing code against the same mask
(vga_draw_logo, vga_logo_centered) for things that want the mark after
boot — the crash screen, eventually schinit. Don't "fix" the duplication by
deleting the loader's copy.
Pipeline: tools/mklogo.py (host Python, has its own PNG inflate +
un-filter) crops to the mark, box-downscales, normalises to full strength, packs
to a 4-bit coverage mask, and writes include/logo.h. Run make logo — it is
not a build dependency, and include/logo.h is committed, on the same
reasoning as include/font.h. The mask is coverage, not colour, so the palette
stays in schunix-console-tty's include/theme.h; the loader composites it in
SCH_FG because the source art is a silver gradient and the accent is reserved
for the one rule. 4 bits rather than 8 because the header is included by the
bootloader, where size is a boot constraint.
STAGE2_SECTORS was encoded in five places, not the three docs/layout.md
claimed. Raising it 24 → 48 to fit the 8 KiB mask proved it: the dd seek=25
offset stayed behind and the kernel got written straight over stage2's tail.
The five were boot/bootasm.S, boot/stage2main.c, the dd seek=, and twice
inside tools/mkiso.sh (its size assertion and -boot-load-size). It now lives
only in the root Makefile, which passes -DSTAGE2_SECTORS and exports it to
mkiso; the #defines left in the boot sources are #ifndef fallbacks. Hard
ceiling is 65 sectors — stage2 loads at 0x7E00 and must not reach the
multiboot kernel-search buffer at 0x10000 — and stage2main.c now
static-asserts that. See also schunix-iso-boot.
tools/splashshot.ps1 captures a burst of QEMU screendumps across early
boot and reports each frame's distinct-colour count, because the splash window
is too short to hit with a single guessed delay. It uses -snapshot plus
file.locking=off so it runs while an interactive QEMU has the images open —
booting from copies also works but means duplicating all 153 MB of
build/fs.img per run. Colour counts are the
assertion: ~2 means text console or blank, 18 means the 4bpp logo is up. If it
ever reads 156 again, something is drawing an 8-bit mask.
Two traps, both hit while doing this:
$(shell expr $(N) \* 512)in a Makefile does not work — make passes the backslash through, sh globs the*, and expr receives a directory listing. Make silently carries on with nonsense. Use$$(( ))in the recipe.make isowas failing when this was written, for unrelated reasons since fixed — see schunix-ramdisk-root-sizing.-boot-load-size 49is now verified: the ISO boots from optical media only.