systemd-getty-generator reads console=ttyS0 off the kernel cmdline and
auto-creates serial-getty@ttyS0.service, which BindsTo dev-ttyS0.device.
On hardware without a physical serial port the device node never shows
up, systemd waits its full default 90s timeout, and only then proceeds.
systemd.mask= on the kernel cmdline is a first-class option — masks
the unit before the generator's link even gets activated. Kernel
messages still go to ttyS0 if a port is present; we just don't try
to spawn a login prompt there.
Host boots past kernel init and then stalls silently. ACPI DSDT error
about TXHC.RHUB.SS01 is benign noise (Tiger Lake firmware bug) — the
actual problem is that nothing between kernel handoff and (maybe)
systemd is visible on the console.
Two changes:
1. Replace the /init → sbin/init symlink with a real shell script
(live-image/mkosi.extra/init) that mounts /proc /sys /dev /dev/pts
/dev/shm /run before execing systemd. Systemd has fallback mount
code for these, but when it fails the failure is silent. Doing it
explicitly in /init keeps failures visible and avoids the fragile
symlink-resolution trick.
2. Drop 'quiet' from the kernel cmdline and add loglevel=7 plus
systemd.log_target=kmsg + journald.forward_to_console=1 so every
early-boot message reaches both tty0 and ttyS0. Will be dialed
back once boot is stable.
Also: .gitattributes pins LF on live-image/, .gitea/, Makefile, and
*.sh so Windows checkouts don't break shell scripts and Makefile
recipes with CRLF. /init also gets chmod 0755 in repack-initrd as a
belt-and-braces against mode loss on non-Linux checkouts.
josh