mkinitcpio & Initramfs Presets

Initramfs = tiny OS that finds/unlocks your real root. AcreetionOS regenerates it via hooks whenever kernels update (Pacman Hooks).

Presets drive everything

# /etc/mkinitcpio.d/linux.preset
ALL_kver="/boot/vmlinuz-linux"
PRESETS=('default' 'fallback')
default_image="/boot/initramfs-linux.img"
fallback_options="-S autodetect"     # fallback = EVERYTHING compiled in

Fallback image is why "kernel updated weirdly" often still boots — autodetect omitted means maximum driver inclusion.

HOOKS array semantics

HOOKS=(base udev autodetect microcode modconf kms keyboard keymap consolefont block encrypt lvm2 filesystems fsck shutdown)

Order = dependency truth:

block before encrypt/lvm2 before filesystems
keyboard+keymap REQUIRED before encrypt or passphrase layout breaks
kms early gives native-res splash (Plymouth friendliness)

Changed something? Rebuild ALL presets:

sudo mkinitcpio -P
lsinitcpio --analyze /boot/initramfs-linux.img | less    # audit contents

MODULES vs autodetect

MODULES=(i915 nvidia nvidia_modeset) force-includes early loading (splash/hybrid graphics). Autodetect handles the rest; conflicts resolve toward explicitness.

Compression & speed

Default zstd balances size/speed; COMPRESSION="lz4" trades ~20% size for faster unpack on slow CPUs. Gzip-era advice obsolete.

Debugging early-boot failures

Add break=y kernel param → drops to initramfs emergency shell pre-root-mount; from there exit continues boot attempt. Journal of early phase: journalctl -b -p warning post-success shows what nearly went wrong.