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.
2.6 KiB
| name | description | metadata | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| schunix-iso-boot | `make iso` builds a bootable CD; it needs El Torito no-emulation plus ATAPI because the loader never uses INT 13h |
|
make iso produces a bootable schunix.iso (added 2026-08-04). Always a
RAMROOT build — a disc that needed a second disk for its root would not be an
install medium, and read-only media cannot host a writable root anyway.
Why it is built the way it is. Schunix's loader never calls INT 13h: it drives the IDE registers directly, and stage2 has already switched to protected mode before it reads the kernel. That rules out both El Torito emulation modes (hard-disk emulation exists only through the BIOS) and floppy emulation (2.88 MB cap). So:
boot/cdboot.S— a separate stage 1 for optical media.tools/mkiso.shpasses-boot-load-size 25, so the BIOS loads cdboot and all 24 sectors of stage2 before anything of ours runs, putting stage2 at 0x7E00 exactly wherebootasm.Swould have. cdboot only records the medium and jumps.- The medium flag is one byte past the verbose flag, at
VBE_INFO_ADDR + 0x101.bootasm.Smust clear it or a warm reboot from a disc sends a hard-disk boot looking for an optical drive. stage2main.cgained an ATAPI reader (PACKET + SCSI READ(12), 2048-byte blocks with a one-block cache) and finds where it was loaded from by reading the El Torito boot catalog: LBA 17, pointer at offset 0x47, then Load RBA at catalog offset 40.- Do not pass
-boot-info-tableto xorriso — it patches 56 bytes over offset 8 of the boot image, which is the middle of cdboot's code. That is why the boot catalog is parsed instead.
The trap that cost the most time here: ATAPI's 0x14/0xEB signature is only
valid until something issues a command, and the BIOS has just finished reading
the disc to load us — so on a CD boot the signature is always stale.
atapi_reset() (SRST via the control port at io + 0x206) is what makes the
probe work.
Two unbounded waits were hiding behind that, both of which hung with no
message on a machine with no ATA disk: waitdisk() in stage2main.c and
idewait() in kernel/dev/ide.c. Both are bounded now, ideinit() tolerates an
empty channel, and anything that probes a disk must call
ide_disk_present() first — iderw() rightly panics on an absent drive.
Check it with pwsh -File tools/bootcheck.ps1 -Iso -Fb, which boots with no
hard disk attached at all. See schunix-verify-by-driving-shell.