hp-chell/NEON-CUSTOMIZATIONS.md

Other neon customizations on hp-chell

Reconstructed on 2026-09-27 from ~matt/.bash_history (551 lines, roughly early March 2026 onward), /root/.bash_history, and the live system. Topics with their own docs: AUDIO.md, ZRAM.md, CHROMEOS-FLEX.md, and the kernel 7.x black-screen fix in CLAUDE.md.

Keyboard: keyd remapping for the Chromebook layout

The Chromebook keyboard has no F-keys, Delete, Home/End, PgUp/PgDn or Caps Lock; there's a "Search" key where Caps Lock would be. keyd remaps it at the evdev level, so it works everywhere (console, X, Wayland, the login screen).

• Built from source, not from apt (apt has no keyd for noble): ~/github/keyd (https://github.com/rvaiya/keyd, 7c0aecb, v2.6.0), make && sudo make install, which puts the binary at /usr/local/bin/keyd. Then sudo systemctl enable --now keyd. Neither apt nor unattended upgrades will ever update it; rebuild from the checkout to upgrade.
• Config: /etc/keyd/default.conf. Apply edits with sudo keyd reload; find key names and device IDs with sudo keyd monitor. Summary:
  • [ids] 0001:0001: only the internal keyboard (AT Translated Set 2 keyboard); external USB keyboards are left alone (use * to include them).
  • leftmeta = overload(meta, leftmeta): Search acts as Meta when held and taps as Meta (opens the KDE launcher).
  • Search + top row gives F1 to F10 (back, forward, refresh, zoom, scale, brightness down/up, mute, volume down/up). Search + -/= gives F11/F12.
  • The same top-row to F-key mapping with Alt, Ctrl or Shift held. The A-/C-/S- prefixes re-apply the modifier, which keyd otherwise strips, so e.g. Alt+F4 works as Alt+Search+Zoom.
  • Search + Backspace = Delete; Search + arrows = Home/End/PgUp/PgDn.
  • Alt + Backspace = Delete; Alt + Search = Caps Lock.

USB-C DisplayPort output: load the cros_ec Type-C drivers

/etc/modules-load.d/cros-video.conf (2026-03-12):

cros_ec_typec
typec_displayport

These don't autoload on chell, and without them the USB-C ports don't negotiate DisplayPort alt mode, so there's no video out over USB-C. Both are loaded as of 2026-09-27.

Kernel: HWE-edge meta package

linux-generic-hwe-24.04-edge is installed (alongside the plain linux-generic-hwe-24.04), and it's why the machine is on 7.x kernels (7.0.0-34 now), not noble's regular HWE line. Also installed deliberately as a known-good fallback: linux-image-generic-6.17 / linux-headers-generic-6.17 (6.17.0-42), which is the fallback kernel named in the black-screen notes in CLAUDE.md. Old 7.x kernels (7.0.0-30, 7.0.0-14) are still installed as well.

/etc/default/grub (edited by hand several times; both matt and root history show nano /etc/default/grub + update-grub): GRUB_DEFAULT=0, GRUB_TIMEOUT=5, GRUB_TIMEOUT_STYLE=menu, GRUB_CMDLINE_LINUX_DEFAULT='splash' (see setup-i915-kernel7-fix.sh).

Storage / wear on the microSD root

neon's root is a microSD card in the built-in slot (sda; the slot's reader is USB-attached internally), and microSD handles lots of small writes poorly, so a few changes cut down writes and space use:

• /tmp is tmpfs (in /etc/fstab: tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0). Not in the shell history, so it was probably added in the same nano /etc/fstab edit that disabled the swapfile.
• The swapfile was replaced by zram (see ZRAM.md).
• localepurge is installed and configured (via dpkg-reconfigure localepurge) to keep only en, en_CA.UTF-8, en_US.UTF-8 and fr_CA.UTF-8, and delete other locales' files on every package install (USE_DPKG, MANDELETE). If another language's translations or man pages are ever needed, add them with sudo dpkg-reconfigure localepurge.
• Root mounted with commit=30 (2026-09-27): the root line in /etc/fstab is defaults,commit=30; the pre-change copy is /etc/fstab.bak-2026-09-27. ext4 commits its journal every 30s instead of every 5s, so writes are batched into fewer, larger bursts. Trade-off: a crash or forced power-off can lose up to ~30s of recent changes that weren't fsync'd (apt/dpkg, editors and databases fsync, so they're unaffected). 30 rather than 60 because this machine has needed forced power-offs. relatime is kept deliberately (not noatime).
• journald capped at 100MB (2026-09-27): /etc/systemd/journald.conf.d/50-max-size.conf sets SystemMaxUse=100M (it was 455MB).
• smartmontools disabled (2026-09-27, systemctl disable --now): it failed on every boot because neither the microSD card nor the eMMC supports SMART.
• Marked non-rotational (2026-09-27): the Genesys reader reported rotational=1 (a spinning disk). /etc/udev/rules.d/61-microsd-nonrotational.rules sets queue/rotational=0 for ID_VENDOR_ID=05e3, ID_MODEL_ID=0747, so lsblk -d -o NAME,ROTA shows 0.
• The card doesn't support discard/TRIM (lsblk -D shows 0), so fstrim.timer does nothing for it. That's harmless and was left alone.

Suspend: stay on s2idle; do NOT use S3 (deep)

Tested 2026-09-27. The firmware offers both s2idle (default) and deep (ACPI S3) in /sys/power/mem_sleep.

• An RTC-woken 30s S3 test (rtcwake -m mem -s 30 with mem_sleep=deep) entered and left S3 cleanly, and the display came back. The i915 bug didn't show.
• A real lid-close S3 suspend broke the root filesystem: on resume the built-in microSD reader (USB, Genesys 05e3:0747) didn't come back in time, the kernel logged disk I/O errors, and ext4 remounted / read-only (errors=remount-ro). Nothing was logged because root was read-only (the previous boot's journal just stops). After a forced reboot, the initramfs fsck replayed the journal and reported the filesystem clean; no lasting damage was found.
• In S3 the USB controller loses power, so the reader has to be re-attached. USB "persist" (power/persist=1, the kernel feature meant for root on USB storage) was already on and didn't save it. There's no dependable fix, so never set mem_sleep_default=deep while neon's root is on the microSD slot.
• s2idle keeps USB powered and has worked for months. It does reach S0ix: in a 44s lid-close test (2026-09-28), /sys/kernel/debug/pmc_core/slp_s0_residency_usec (needs root) grew by ~42.2s, and package_cstate_show showed Package C10 ~42.0s. So ~96% of the suspend was in the deepest idle state, and drain should be close to S3's. Root stayed rw with no I/O errors.
• Use the pmc_core counter above, not /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us. That one comes from ACPI LPIT, which isn't wired up properly under coreboot here: it read 270µs for the same suspend.

Suspend-then-hibernate (set up 2026-09-28)

A lid close suspends (s2idle, instant). If the machine is still asleep after 3 hours, systemd wakes it (RTC), writes a hibernation image to disk and powers off. This protects against a dead battery without writing a multi-GB image on every lid close, which is why this was chosen over hybrid sleep. It doesn't need S3.

Pieces:

• 16GB /swapfile, used for the hibernation image (sized to RAM for the worst case; a typical image is ~4GB). fstab /swapfile none swap sw,pri=10 0 0: priority 10 < zram's 100, so normal swapping still goes to zram. Backup of the old fstab: /etc/fstab.bak-2026-09-28.
• Resume location: resume=UUID=3af45daa-b8c2-4053-9574-a958e0c3ea68 resume_offset=17674240 in GRUB_CMDLINE_LINUX_DEFAULT (backup /etc/default/grub.bak-2026-09-28) and in /etc/initramfs-tools/conf.d/resume, then update-initramfs -u -k all
  • update-grub. If /swapfile is ever recreated, its offset changes. Get the new one with sudo filefrag -v /swapfile | awk '$1=="0:"{print $4}' (strip the trailing ..), then update both places and rerun both commands.
• /etc/systemd/sleep.conf.d/50-suspend-then-hibernate.conf: HibernateDelaySec=3h.
• /etc/polkit-1/rules.d/10-enable-hibernate.rules: Ubuntu's /usr/share/polkit-1/rules.d/com.ubuntu.desktop.rules returns NO for all login1/upower hibernate actions, so logind reported CanHibernate/CanSuspendThenHibernate = no even though its sleep checks passed (seen with systemctl service-log-level systemd-logind debug). This rule sorts earlier and returns YES for local, active users.
• Plasma: PowerDevil owns the lid, so each Power Management profile's sleep mode must be set to "Standby, then hibernate" in System Settings.

Tested 2026-09-28 with systemctl hibernate: a 3.8GB image, powered off, and the session resumed intact (uptime carried over, root rw). Right after resume, one readahead READ failed on sda ("device offline or changed") while the microSD reader was being reset. That's harmless: readahead failures are dropped, and ext4 logged no errors and stayed clean. It's the same reader re-attach that breaks S3, but a hibernate resume is a cold boot and the reader was back in time.

Networking

• Realtek USB Ethernet (enx00e04c68003e, r8152-family 2.5G adapter): the out-of-tree driver from https://github.com/awesometic/realtek-r8152-dkms (~/github/realtek-r8152-dkms) was once installed with DKMS, together with unloading cdc_ether / cdc_ncm / cdc_mbim and testing with iperf3 against pet630, MTU 9000 and ethtool -K offloads. It was later removed (sudo ./dkms-remove.sh) because it failed to build against the 7.x kernels (confirmed by matt, 2026-09-27). dkms status is empty now, so the adapter gets the in-kernel driver. The MTU and offload tweaks were runtime-only and aren't persisted anywhere.
• Tailscale is installed (repo in tailscale.list) but tailscaled is disabled (systemctl disable tailscaled, around the time the agent account was created).

Firmware and access

• MrChromebox firmware utility run twice (curl -LOf https://mrchromebox.tech/firmware-util.sh && sudo bash firmware-util.sh); the second run was the 2026-09-03 update to MrChromebox-2606.1 (see CLAUDE.md).
• agent-user created with create-agent-user.sh from https://gist.ergosteur.com/ergosteur/41df939a435741bfac431ac3d4b888d0 (a copy is in ~matt).

Software and third-party apt repos

Not hardware-specific, but needed to rebuild the machine. The repositories in /etc/apt/sources.list.d/ beyond neon's own:

Source file	What	Set up via
vscodium.sources	VSCodium (codium)	paulcarroty key into /usr/share/keyrings/vscodium-archive-keyring.gpg
google-chrome.sources	Google Chrome	installing the .deb from Downloads; set as x-www-browser / gnome-www-browser via update-alternatives
docker.sources	Docker CE	Docker's official apt instructions; matt added to the docker group
ansible-ubuntu-ansible-noble.sources	ansible-core	ppa:ansible/ansible
nodesource.sources	Node.js 24	deb.nodesource.com/setup_24.x; then npm i -g @google/gemini-cli
tailscale.list	Tailscale	(disabled, see above)

Other tools installed by hand:

• bws (Bitwarden Secrets Manager CLI) v2.0.0: unzipped into /opt/bitwarden/bws/, symlinked to /usr/local/bin/bws, with completions in /opt/bitwarden/bws/completions.bash sourced from ~/.bashrc.
• GlobalProtect VPN (PanGPLinux-6.3.3-c31, gp_install.sh, from ~/Downloads).
• pipx: mkdocs plus the injected mkdocs-material.
• Claude Code (curl -fsSL https://claude.ai/install.sh | bash).

Notable apt packages installed on top of neon: codium ffmpeg yt-dlp imagemagick python3-pip python3-venv pipx python3-bs4 build-essential ncdu bwm-ng wireshark mpv filezilla rpi-imager ntfs-3g exfatprogs exfat-fuse hfsutils hfsprogs samba samba-vfs-modules krdc remmina ssh iperf3 netcat-openbsd htop btop git pavucontrol-qt bash-completion tesseract-ocr{,-eng,-fra,-kor} inxi lsscsi qrencode localepurge zram-tools dkms.

Git identities: ~/.gitconfig plus ~/.gitconfig.ergosteur and ~/.gitconfig.tfo, with SSH key aliases in ~/.ssh: git_ssh_id_ergosteur → id_rsa, and git_ssh_id_myip4tfo → id_ed25519.

Dead ends in the history (nothing left installed)

• ~/github/chell_audio (iofq's chell audio repo) was cloned and linux-modules-extra / snd_soc_skl poked at, before switching to WeirdTreeThing's scripts (see AUDIO.md).
• ntfs2btrfs / ntfsfix against a /dev/sda1 of the time. That was an external data card before this layout, not the current neon install, whose sda1 is its ESP.