# NixOS Build Spec (sam-4screen-desktop)

## Disk / Boot (WIPE ENTIRE NVMe DISK)

Target disk: /dev/nvme0n1
- Size: 953.87 GiB (1024209543168 bytes), 2000409264 sectors
- Model: PM951 NVMe SAMSUNG 1024GB
- NVMe serial: S2FZNXAH301424
- NVMe WWID: nvme.144d-2020202020205332465a4e584148333031343234-504d393531204e564d652053414d53554e4720313032344742-00000001
- Sector size (logical/physical): 512 bytes / 512 bytes

DECISION (CONFIRMED):
- Do NOT keep Windows.
- Wipe the entire /dev/nvme0n1 (all existing partitions will be deleted/overwritten).

Installer safety:
- Install target is NVMe only. Do not select /dev/sdX devices in the installer.
- Device names like /dev/sdb, /dev/sdc can change across boots; always rely on UUID/label when mounting non-target disks.

Verification commands (run before wiping, if you want one last check):
- `lsblk -o NAME,SIZE,TYPE,FSTYPE,LABEL,UUID,MOUNTPOINTS`
- `sudo fdisk -l /dev/nvme0n1`

Boot method:
- UEFI
- Bootloader: systemd-boot

Filesystem / layout:
- Root filesystem: Btrfs (with subvolumes)
- Encryption: none
- Swap: zram
- Hibernate: no
- /home: Btrfs subvolume

Partitioning approach:
- Manual in the installer (no disko)

Recommended layout:
- New GPT on /dev/nvme0n1
- EFI System Partition (vfat), mounted at /boot
- Btrfs partition for the rest
  - Subvolume @ mounted at /
  - Subvolume @home mounted at /home

IMPORTANT:
- `hosts/sam-4screen-desktop/hardware-configuration.nix` is currently a placeholder.
- During install after mounting to /mnt:
  1) Run: `nixos-generate-config --root /mnt`
  2) Copy: `/mnt/etc/nixos/hardware-configuration.nix` into:
     `hosts/sam-4screen-desktop/hardware-configuration.nix`

## Other attached disks (DO NOT FORMAT)
- /dev/sda (240GB) model: Patriot Burst El (KEEP)
  - /dev/sda1: Microsoft reserved partition (~15MiB)
  - /dev/sda2: NTFS label "Back Up" (keep)
- TempBackup (ext4) UUID=4f9c4bd5-fea5-408f-9370-731fc095da3f (~465GiB/500GB) (KEEP)
  - Model: WD5000BEVT-22ZAT
  - Serial: WD-WXNY08ND2684
  - NOTE: device name may appear as /dev/sdX depending on boot/USB order; identify by UUID/label/model.
- Integral300 (ext4) UUID=27febd74-20aa-4a3a-92c1-6fdd1ad7e88e (~298GiB/320GB)
  - Mount at /data
  - NOTE: device name may change; config always uses /dev/disk/by-uuid.
- XPSystemDrive (ext4) UUID=82c994f1-9adb-49e4-ba1e-5b6e5ccbd49b (~149GiB/160GB) (KEEP)
  - Model: HTS541616J9SA00 (Hitachi)
  - NOTE: device name may appear as /dev/sdX depending on boot/USB order; identify by UUID/label/model.

## Networking
- Use NetworkManager

Static IPv4 policy (CONFIRMED):
- Static IPv4 should be applied to Wi-Fi SSID:
  - SSID / connection id: "Aussie Broadband 8729"
  - Interface: wlp4s2
  - IP: 192.168.20.27/24
  - Gateway: 192.168.20.1
  - DNS: 192.168.20.35, 192.168.20.13
- Wired enp0s31f6: no static IP required for now

Secrets policy:
- Do not commit Wi-Fi PSKs to git.
- Static IP enforcement is implemented via a NetworkManager dispatcher script.

## Data drive mount
- Integral300 ext4 UUID=27febd74-20aa-4a3a-92c1-6fdd1ad7e88e
- Mountpoint on NixOS: /data (preferred)

## Dotfiles policy
- Dotfiles live on the installed system at: ~/dotfiles
- Do not depend on /data for dotfiles.

## Desktop
- Primary compositor: Niri
- Display/login manager: greetd + tuigreet
- Session start command: `niri --session` (do not use `niri-session`)
- GPU: Intel HD 630 + NVIDIA Quadro P620
- Display appears to be driven by NVIDIA Quadro P620 (observed `/dev/fb0` on Ubuntu scan). Treat NVIDIA as primary unless proven otherwise.

## Secrets policy
- No API keys or WiFi PSKs committed to git