Arch Linux T2 installer for 2019 MacBook Pro + Omarchy

arch-t2-install.sh

#!/bin/bash
# =============================================================================
# Arch Linux T2 Mac Installer + Omarchy Setup
# For: 2019 MacBook Pro (T2 chip)
# Run from: archlinux-t2 live USB
#
# Usage: curl -sL <gist-url> | bash
#   Or:  bash arch-t2-install.sh
# =============================================================================

set -euo pipefail

DISK="/dev/nvme0n1"
EFI_SIZE="512M"
SWAP_SIZE="16G"
HOSTNAME="macbook"
USERNAME="cobb"
TIMEZONE="America/Chicago"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
NC='\033[0m'

info()  { echo -e "${GREEN}[*]${NC} $1"; }
warn()  { echo -e "${YELLOW}[!]${NC} $1"; }
err()   { echo -e "${RED}[✗]${NC} $1"; }
step()  { echo -e "\n${CYAN}=== $1 ===${NC}\n"; }

# ---------------------------------------------------------------------------
# Pre-flight checks
# ---------------------------------------------------------------------------
step "Pre-flight Checks"

if [ "$(id -u)" -ne 0 ]; then
    err "Run this script as root"
    exit 1
fi

if [ ! -b "$DISK" ]; then
    err "${DISK} not found. Available disks:"
    lsblk -d -o NAME,SIZE,MODEL
    echo ""
    read -rp "Enter disk path (e.g. /dev/sda): " DISK
    if [ ! -b "$DISK" ]; then
        err "${DISK} not found. Aborting."
        exit 1
    fi
fi

# Detect partition suffix (nvme uses p1, sda uses 1)
if [[ "$DISK" == *"nvme"* ]]; then
    PART="${DISK}p"
else
    PART="${DISK}"
fi

info "Target disk: ${DISK}"
info "Partitions:  EFI=${EFI_SIZE}  Swap=${SWAP_SIZE}  Root=remaining"
info "Hostname:    ${HOSTNAME}"
info "User:        ${USERNAME}"
echo ""

lsblk "$DISK"
echo ""
echo -e "${RED}WARNING: This will ERASE ALL DATA on ${DISK}${NC}"
read -rp "Type 'YES' to continue: " confirm
if [ "$confirm" != "YES" ]; then
    echo "Aborted."
    exit 0
fi

# ---------------------------------------------------------------------------
# 1. Partition
# ---------------------------------------------------------------------------
step "1/9 — Partitioning ${DISK}"

sgdisk --zap-all "$DISK"
sgdisk --new=1:0:+"${EFI_SIZE}" --typecode=1:ef00 --change-name=1:"EFI"  "$DISK"
sgdisk --new=2:0:+"${SWAP_SIZE}" --typecode=2:8200 --change-name=2:"swap" "$DISK"
sgdisk --new=3:0:0              --typecode=3:8300 --change-name=3:"root" "$DISK"
partprobe "$DISK"
sleep 2

info "Partition table:"
sgdisk -p "$DISK"

# ---------------------------------------------------------------------------
# 2. Format
# ---------------------------------------------------------------------------
step "2/9 — Formatting"

mkfs.fat -F32 "${PART}1"
info "EFI formatted (FAT32)"

mkswap "${PART}2"
info "Swap formatted"

mkfs.btrfs -f "${PART}3"
info "Root formatted (btrfs)"

# ---------------------------------------------------------------------------
# 3. Mount
# ---------------------------------------------------------------------------
step "3/9 — Mounting"

mount "${PART}3" /mnt

# Create btrfs subvolumes for better snapshot support
btrfs subvolume create /mnt/@
btrfs subvolume create /mnt/@home
umount /mnt

mount -o noatime,compress=zstd,subvol=@ "${PART}3" /mnt
mkdir -p /mnt/{boot,home}
mount -o noatime,compress=zstd,subvol=@home "${PART}3" /mnt/home
mount "${PART}1" /mnt/boot
swapon "${PART}2"

info "Mounted: root=@ home=@home boot=EFI swap=on"

# ---------------------------------------------------------------------------
# 4. Configure T2 repo (live environment)
# ---------------------------------------------------------------------------
step "4/9 — Configuring T2 Repository"

if ! grep -q "arch-mact2" /etc/pacman.conf 2>/dev/null; then
    cat >> /etc/pacman.conf << 'EOF'

[arch-mact2]
Server = https://mirror.funami.tech/arch-mact2/os/x86_64
SigLevel = Never
EOF
    info "Added arch-mact2 repo to live environment"
else
    info "arch-mact2 repo already configured"
fi

pacman -Sy --noconfirm

# ---------------------------------------------------------------------------
# 5. Install base system
# ---------------------------------------------------------------------------
step "5/9 — Installing Base System (this takes a while)"

pacstrap -K /mnt \
    base linux-t2 linux-t2-headers linux-firmware \
    base-devel \
    networkmanager iwd wireless_tools wpa_supplicant \
    apple-bcm-firmware \
    btrfs-progs efibootmgr dosfstools \
    grub \
    git vim nano sudo man-db \
    bluez bluez-utils \
    pipewire pipewire-alsa pipewire-pulse wireplumber \
    zsh wget curl unzip

# T2 hardware packages (may fail if repo is unavailable, non-fatal)
pacstrap -K /mnt apple-t2-audio-config t2fanrd tiny-dfr 2>/dev/null || \
    warn "Some T2 packages not available — install manually after boot"

info "Base system installed"

# ---------------------------------------------------------------------------
# 6. Generate fstab
# ---------------------------------------------------------------------------
step "6/9 — Generating fstab"

genfstab -U /mnt >> /mnt/etc/fstab
info "fstab generated:"
cat /mnt/etc/fstab

# ---------------------------------------------------------------------------
# 7. Add T2 repo to installed system
# ---------------------------------------------------------------------------
step "7/9 — Configuring Installed System"

cat >> /mnt/etc/pacman.conf << 'EOF'

[arch-mact2]
Server = https://mirror.funami.tech/arch-mact2/os/x86_64
SigLevel = Never
EOF

info "T2 repo added to installed system"

# ---------------------------------------------------------------------------
# 8. Chroot configuration
# ---------------------------------------------------------------------------
step "8/9 — System Configuration (chroot)"

arch-chroot /mnt /bin/bash << CHROOTEOF
set -e

# Timezone
ln -sf /usr/share/zoneinfo/${TIMEZONE} /etc/localtime
hwclock --systohc
echo "Timezone set to ${TIMEZONE}"

# Locale
echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen
locale-gen
echo "LANG=en_US.UTF-8" > /etc/locale.conf

# Hostname
echo "${HOSTNAME}" > /etc/hostname
cat > /etc/hosts << HOSTS
127.0.0.1   localhost
::1         localhost
127.0.1.1   ${HOSTNAME}.localdomain ${HOSTNAME}
HOSTS

# T2 kernel modules for initramfs
sed -i 's/^MODULES=.*/MODULES=(btrfs apple_bce hid_apple usbhid xhci_hcd)/' /etc/mkinitcpio.conf
mkinitcpio -P

# Bootloader
grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB --removable
grub-mkconfig -o /boot/grub/grub.cfg

# Enable services
systemctl enable NetworkManager
systemctl enable bluetooth
systemctl enable t2fanrd 2>/dev/null || true

# Create user
useradd -m -G wheel,audio,video,input -s /bin/zsh ${USERNAME}
echo "${USERNAME}:changeme" | chpasswd
echo "root:changeme" | chpasswd
echo "%wheel ALL=(ALL:ALL) ALL" >> /etc/sudoers

# WiFi power management off (helps T2 Broadcom)
mkdir -p /etc/NetworkManager/conf.d
cat > /etc/NetworkManager/conf.d/wifi-powersave.conf << NMCONF
[connection]
wifi.powersave = 2
NMCONF

echo "Chroot configuration complete"
CHROOTEOF

info "System configured"

# ---------------------------------------------------------------------------
# 9. Post-install notes
# ---------------------------------------------------------------------------
step "9/9 — Done!"

cat << 'DONE'

 ┌─────────────────────────────────────────────────┐
 │           Installation Complete!                 │
 │                                                  │
 │  User:     cobb                                  │
 │  Password: changeme  (CHANGE THIS!)              │
 │  Root pw:  changeme  (CHANGE THIS!)              │
 └─────────────────────────────────────────────────┘

 Next steps:

   1.  umount -R /mnt && reboot

   2.  Remove USB, hold Option key, select GRUB

   3.  Login as 'cobb', connect to WiFi:
         nmtui

   4.  Change your passwords:
         passwd
         sudo passwd root

   5.  Install Omarchy:
         git clone https://github.com/basecamp/omarchy.git ~/.omarchy
         cd ~/.omarchy
         # Review install scripts, then:
         # ./install.sh  (or follow their README)

   6.  If WiFi doesn't work:
         sudo rfkill unblock all
         sudo modprobe brcmfmac

DONE