Phase 1.1: Create lib/ directory structure for archangel refactor

- Add custom/lib/common.sh: output, validation, fzf prompts, disk utils
- Add custom/lib/config.sh: argument parsing, config loading, validation
- Add custom/lib/disk.sh: partitioning, EFI management, disk selection
- Add custom/lib/zfs.sh: pool, datasets, ZFSBootMenu, services, hooks
- Update install-archzfs to source libs
- Remove duplicated output/config functions from main script

Prepares codebase for btrfs filesystem support (Phase 2).

6 files changed, 839 insertions, 82 deletions

diff --git a/custom/install-archzfs b/custom/install-archzfs
index a17aad5..6f098cc 100755
--- a/custom/install-archzfs
+++ b/custom/install-archzfs
@@ -19,6 +19,16 @@
 set -e
 
 #############################
+# Source Library Functions
+#############################
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/lib/common.sh"
+source "$SCRIPT_DIR/lib/config.sh"
+source "$SCRIPT_DIR/lib/disk.sh"
+source "$SCRIPT_DIR/lib/zfs.sh"
+
+#############################
 # Configuration
 #############################
 
@@ -56,93 +66,16 @@ echo "install-archzfs started @ $(date +'%Y-%m-%d %H:%M:%S')"
 echo "================================================================================"
 echo ""
 
-info()  { echo "[INFO] $1"; }
-warn()  { echo "[WARN] $1"; }
-error() { echo "[ERROR] $1"; exit 1; }
-step()  { echo ""; echo "==> $1"; }
-prompt() { echo "$1"; }
-
-#############################
-# Config File Support
-#############################
-
-CONFIG_FILE=""
-UNATTENDED=false
-
-parse_args() {
-    while [[ $# -gt 0 ]]; do
-        case "$1" in
-            --config-file)
-                if [[ -n "$2" && ! "$2" =~ ^- ]]; then
-                    CONFIG_FILE="$2"
-                    shift 2
-                else
-                    error "--config-file requires a path argument"
-                fi
-                ;;
-            --help|-h)
-                echo "Usage: install-archzfs [OPTIONS]"
-                echo ""
-                echo "Options:"
-                echo "  --config-file PATH  Use config file for unattended installation"
-                echo "  --help, -h          Show this help message"
-                echo ""
-                echo "Without --config-file, runs in interactive mode."
-                echo "See /root/install-archzfs.conf.example for a config template."
-                exit 0
-                ;;
-            *)
-                error "Unknown option: $1 (use --help for usage)"
-                ;;
-        esac
-    done
-}
-
-load_config() {
-    local config_path="$1"
-
-    if [[ ! -f "$config_path" ]]; then
-        error "Config file not found: $config_path"
-    fi
-
-    info "Loading config from: $config_path"
-
-    # Source the config file (it's just key=value pairs)
-    # shellcheck disable=SC1090
-    source "$config_path"
-
-    # Convert DISKS from comma-separated string to array
-    if [[ -n "$DISKS" ]]; then
-        IFS=',' read -ra SELECTED_DISKS <<< "$DISKS"
-    fi
-
-    UNATTENDED=true
-    info "Running in unattended mode"
-}
-
-check_config() {
-    # Only use config when explicitly specified with --config-file
-    # This prevents accidental disk destruction from an unnoticed config file
-    if [[ -n "$CONFIG_FILE" ]]; then
-        load_config "$CONFIG_FILE"
-    fi
-}
+# Output functions now in lib/common.sh
+# Config functions now in lib/config.sh
 
 #############################
 # Pre-flight Checks
 #############################
 
 preflight_checks() {
-    # Check root
-    [[ $EUID -ne 0 ]] && error "This script must be run as root"
-
-    # Check ZFS module
-    if ! lsmod | grep -q zfs; then
-        info "Loading ZFS module..."
-        modprobe zfs || error "Failed to load ZFS module. Is zfs-linux-lts installed?"
-    fi
-
-    info "ZFS module loaded successfully."
+    require_root
+    zfs_preflight
 }
 
 #############################
diff --git a/custom/lib/common.sh b/custom/lib/common.sh
new file mode 100644
index 0000000..a41441d
--- /dev/null
+++ b/custom/lib/common.sh
@@ -0,0 +1,136 @@
+#!/usr/bin/env bash
+# common.sh - Shared functions for archangel installer
+# Source this file: source "$(dirname "$0")/lib/common.sh"
+
+#############################
+# Output Functions
+#############################
+
+# Colors (optional, gracefully degrade if not supported)
+if [[ -t 1 ]]; then
+    RED='\033[0;31m'
+    GREEN='\033[0;32m'
+    YELLOW='\033[0;33m'
+    BLUE='\033[0;34m'
+    BOLD='\033[1m'
+    NC='\033[0m' # No Color
+else
+    RED=''
+    GREEN=''
+    YELLOW=''
+    BLUE=''
+    BOLD=''
+    NC=''
+fi
+
+info()   { echo -e "${GREEN}[INFO]${NC} $1"; }
+warn()   { echo -e "${YELLOW}[WARN]${NC} $1"; }
+error()  { echo -e "${RED}[ERROR]${NC} $1"; exit 1; }
+step()   { echo ""; echo -e "${BOLD}==> $1${NC}"; }
+prompt() { echo -e "${BLUE}$1${NC}"; }
+
+# Log to file if LOG_FILE is set
+log() {
+    local msg="[$(date +'%Y-%m-%d %H:%M:%S')] $1"
+    if [[ -n "$LOG_FILE" ]]; then
+        echo "$msg" >> "$LOG_FILE"
+    fi
+}
+
+#############################
+# Validation Functions
+#############################
+
+require_root() {
+    [[ $EUID -ne 0 ]] && error "This script must be run as root"
+}
+
+command_exists() {
+    command -v "$1" &>/dev/null
+}
+
+require_command() {
+    command_exists "$1" || error "Required command not found: $1"
+}
+
+#############################
+# FZF Prompts
+#############################
+
+# Check if fzf is available
+has_fzf() {
+    command_exists fzf
+}
+
+# Generic fzf selection
+# Usage: result=$(fzf_select "prompt" "option1" "option2" ...)
+fzf_select() {
+    local prompt="$1"
+    shift
+    local options=("$@")
+
+    if has_fzf; then
+        printf '%s\n' "${options[@]}" | fzf --prompt="$prompt " --height=15 --reverse
+    else
+        # Fallback to simple select
+        PS3="$prompt "
+        select opt in "${options[@]}"; do
+            if [[ -n "$opt" ]]; then
+                echo "$opt"
+                break
+            fi
+        done
+    fi
+}
+
+# Multi-select with fzf
+# Usage: readarray -t results < <(fzf_multi "prompt" "opt1" "opt2" ...)
+fzf_multi() {
+    local prompt="$1"
+    shift
+    local options=("$@")
+
+    if has_fzf; then
+        printf '%s\n' "${options[@]}" | fzf --prompt="$prompt " --height=20 --reverse --multi
+    else
+        # Fallback: just return all options (user must edit)
+        printf '%s\n' "${options[@]}"
+    fi
+}
+
+#############################
+# Disk Utilities
+#############################
+
+# Get disk size in human-readable format
+get_disk_size() {
+    local disk="$1"
+    lsblk -dno SIZE "$disk" 2>/dev/null | tr -d ' '
+}
+
+# Get disk model
+get_disk_model() {
+    local disk="$1"
+    lsblk -dno MODEL "$disk" 2>/dev/null | tr -d ' ' | head -c 20
+}
+
+# Check if disk is in use (mounted or has holders)
+disk_in_use() {
+    local disk="$1"
+    [[ -n "$(lsblk -no MOUNTPOINT "$disk" 2>/dev/null | grep -v '^$')" ]] && return 0
+    [[ -n "$(ls /sys/block/"$(basename "$disk")"/holders/ 2>/dev/null)" ]] && return 0
+    return 1
+}
+
+# List available disks (not in use)
+list_available_disks() {
+    local disks=()
+    for disk in /dev/nvme[0-9]n[0-9] /dev/sd[a-z] /dev/vd[a-z]; do
+        [[ -b "$disk" ]] || continue
+        disk_in_use "$disk" && continue
+        local size=$(get_disk_size "$disk")
+        local model=$(get_disk_model "$disk")
+        disks+=("$disk ($size, $model)")
+    done
+    printf '%s\n' "${disks[@]}"
+}
diff --git a/custom/lib/config.sh b/custom/lib/config.sh
new file mode 100644
index 0000000..82f5d77
--- /dev/null
+++ b/custom/lib/config.sh
@@ -0,0 +1,127 @@
+#!/usr/bin/env bash
+# config.sh - Configuration and argument handling for archangel installer
+# Source this file after common.sh
+
+#############################
+# Global Config Variables
+#############################
+
+CONFIG_FILE=""
+UNATTENDED=false
+
+# These get populated by config file or interactive prompts
+HOSTNAME=""
+TIMEZONE=""
+LOCALE=""
+KEYMAP=""
+SELECTED_DISKS=()
+RAID_LEVEL=""
+WIFI_SSID=""
+WIFI_PASSWORD=""
+ENCRYPTION_ENABLED=false
+ZFS_PASSPHRASE=""
+ROOT_PASSWORD=""
+SSH_ENABLED=false
+SSH_KEY=""
+
+#############################
+# Argument Parsing
+#############################
+
+parse_args() {
+    while [[ $# -gt 0 ]]; do
+        case "$1" in
+            --config-file)
+                if [[ -n "$2" && ! "$2" =~ ^- ]]; then
+                    CONFIG_FILE="$2"
+                    shift 2
+                else
+                    error "--config-file requires a path argument"
+                fi
+                ;;
+            --help|-h)
+                show_usage
+                exit 0
+                ;;
+            *)
+                error "Unknown option: $1 (use --help for usage)"
+                ;;
+        esac
+    done
+}
+
+show_usage() {
+    cat <<EOF
+Usage: archangel [OPTIONS]
+
+Arch Linux installer with ZFS/Btrfs support and snapshot management.
+
+Options:
+  --config-file PATH  Use config file for unattended installation
+  --help, -h          Show this help message
+
+Without --config-file, runs in interactive mode.
+See /root/archangel.conf.example for a config template.
+EOF
+}
+
+#############################
+# Config File Loading
+#############################
+
+load_config() {
+    local config_path="$1"
+
+    if [[ ! -f "$config_path" ]]; then
+        error "Config file not found: $config_path"
+    fi
+
+    info "Loading config from: $config_path"
+
+    # Source the config file (it's just key=value pairs)
+    # shellcheck disable=SC1090
+    source "$config_path"
+
+    # Convert DISKS from comma-separated string to array
+    if [[ -n "$DISKS" ]]; then
+        IFS=',' read -ra SELECTED_DISKS <<< "$DISKS"
+    fi
+
+    UNATTENDED=true
+    info "Running in unattended mode"
+}
+
+check_config() {
+    # Only use config when explicitly specified with --config-file
+    # This prevents accidental disk destruction from an unnoticed config file
+    if [[ -n "$CONFIG_FILE" ]]; then
+        load_config "$CONFIG_FILE"
+    fi
+}
+
+#############################
+# Config Validation
+#############################
+
+validate_config() {
+    local errors=0
+
+    [[ -z "$HOSTNAME" ]] && { warn "HOSTNAME not set"; ((errors++)); }
+    [[ -z "$TIMEZONE" ]] && { warn "TIMEZONE not set"; ((errors++)); }
+    [[ ${#SELECTED_DISKS[@]} -eq 0 ]] && { warn "No disks selected"; ((errors++)); }
+    [[ -z "$ROOT_PASSWORD" ]] && { warn "ROOT_PASSWORD not set"; ((errors++)); }
+
+    # Validate disks exist
+    for disk in "${SELECTED_DISKS[@]}"; do
+        [[ -b "$disk" ]] || { warn "Disk not found: $disk"; ((errors++)); }
+    done
+
+    # Validate timezone
+    if [[ -n "$TIMEZONE" && ! -f "/usr/share/zoneinfo/$TIMEZONE" ]]; then
+        warn "Invalid timezone: $TIMEZONE"
+        ((errors++))
+    fi
+
+    [[ $errors -gt 0 ]] && error "Config validation failed with $errors error(s)"
+    info "Config validation passed"
+}
diff --git a/custom/lib/disk.sh b/custom/lib/disk.sh
new file mode 100644
index 0000000..ea8c402
--- /dev/null
+++ b/custom/lib/disk.sh
@@ -0,0 +1,193 @@
+#!/usr/bin/env bash
+# disk.sh - Disk partitioning functions for archangel installer
+# Source this file after common.sh
+
+#############################
+# Partition Disks
+#############################
+
+# Partition a single disk for ZFS/Btrfs installation
+# Creates: EFI partition (512M) + root partition (rest)
+partition_disk() {
+    local disk="$1"
+    local efi_size="${2:-512M}"
+
+    info "Partitioning $disk..."
+
+    # Wipe existing partition table
+    sgdisk --zap-all "$disk" || error "Failed to wipe $disk"
+
+    # Create EFI partition (512M, type EF00)
+    sgdisk -n 1:0:+${efi_size} -t 1:EF00 -c 1:"EFI" "$disk" || error "Failed to create EFI partition on $disk"
+
+    # Create root partition (rest of disk, type BF00 for ZFS or 8300 for Linux)
+    sgdisk -n 2:0:0 -t 2:BF00 -c 2:"ROOT" "$disk" || error "Failed to create root partition on $disk"
+
+    # Notify kernel of partition changes
+    partprobe "$disk" 2>/dev/null || true
+    sleep 1
+
+    info "Partitioned $disk: EFI=${efi_size}, ROOT=remainder"
+}
+
+# Partition multiple disks (for RAID configurations)
+partition_disks() {
+    local efi_size="${1:-512M}"
+    shift
+    local disks=("$@")
+
+    for disk in "${disks[@]}"; do
+        partition_disk "$disk" "$efi_size"
+    done
+}
+
+#############################
+# Partition Helpers
+#############################
+
+# Get EFI partition path for a disk
+get_efi_partition() {
+    local disk="$1"
+    if [[ "$disk" =~ nvme ]]; then
+        echo "${disk}p1"
+    else
+        echo "${disk}1"
+    fi
+}
+
+# Get root partition path for a disk
+get_root_partition() {
+    local disk="$1"
+    if [[ "$disk" =~ nvme ]]; then
+        echo "${disk}p2"
+    else
+        echo "${disk}2"
+    fi
+}
+
+# Get all root partitions from disk array
+get_root_partitions() {
+    local disks=("$@")
+    local parts=()
+    for disk in "${disks[@]}"; do
+        parts+=("$(get_root_partition "$disk")")
+    done
+    printf '%s\n' "${parts[@]}"
+}
+
+# Get all EFI partitions from disk array
+get_efi_partitions() {
+    local disks=("$@")
+    local parts=()
+    for disk in "${disks[@]}"; do
+        parts+=("$(get_efi_partition "$disk")")
+    done
+    printf '%s\n' "${parts[@]}"
+}
+
+#############################
+# EFI Partition Management
+#############################
+
+# Format EFI partition
+format_efi() {
+    local partition="$1"
+    local label="${2:-EFI}"
+
+    info "Formatting EFI partition: $partition"
+    mkfs.fat -F32 -n "$label" "$partition" || error "Failed to format EFI: $partition"
+}
+
+# Format all EFI partitions
+format_efi_partitions() {
+    local disks=("$@")
+    local first=true
+
+    for disk in "${disks[@]}"; do
+        local efi=$(get_efi_partition "$disk")
+        if $first; then
+            format_efi "$efi" "EFI"
+            first=false
+        else
+            format_efi "$efi" "EFI2"
+        fi
+    done
+}
+
+# Mount EFI partition
+mount_efi() {
+    local partition="$1"
+    local mount_point="${2:-/mnt/efi}"
+
+    mkdir -p "$mount_point"
+    mount "$partition" "$mount_point" || error "Failed to mount EFI at $mount_point"
+    info "Mounted EFI: $partition -> $mount_point"
+}
+
+#############################
+# Disk Selection (Interactive)
+#############################
+
+# Interactive disk selection using fzf
+select_disks() {
+    local available
+    available=$(list_available_disks)
+
+    if [[ -z "$available" ]]; then
+        error "No available disks found"
+    fi
+
+    step "Select installation disk(s)"
+    prompt "Use Tab to select multiple disks for RAID, Enter to confirm"
+
+    local selected
+    if has_fzf; then
+        selected=$(echo "$available" | fzf --multi --prompt="Select disk(s): " --height=15 --reverse)
+    else
+        echo "$available"
+        read -rp "Enter disk path(s) separated by space: " selected
+    fi
+
+    [[ -z "$selected" ]] && error "No disk selected"
+
+    # Extract just the device paths (remove size/model info)
+    SELECTED_DISKS=()
+    while IFS= read -r line; do
+        local disk=$(echo "$line" | cut -d' ' -f1)
+        SELECTED_DISKS+=("$disk")
+    done <<< "$selected"
+
+    info "Selected disks: ${SELECTED_DISKS[*]}"
+}
+
+#############################
+# RAID Level Selection
+#############################
+
+select_raid_level() {
+    local num_disks=${#SELECTED_DISKS[@]}
+
+    if [[ $num_disks -eq 1 ]]; then
+        RAID_LEVEL=""
+        info "Single disk - no RAID"
+        return
+    fi
+
+    step "Select RAID level"
+
+    local options=()
+    options+=("mirror - Mirror data across disks (recommended)")
+
+    if [[ $num_disks -ge 3 ]]; then
+        options+=("raidz1 - Single parity, lose 1 disk capacity")
+    fi
+    if [[ $num_disks -ge 4 ]]; then
+        options+=("raidz2 - Double parity, lose 2 disks capacity")
+    fi
+
+    local selected
+    selected=$(fzf_select "RAID level:" "${options[@]}")
+    RAID_LEVEL=$(echo "$selected" | cut -d' ' -f1)
+
+    info "Selected RAID level: $RAID_LEVEL"
+}
diff --git a/custom/lib/zfs.sh b/custom/lib/zfs.sh
new file mode 100644
index 0000000..7862f0d
--- /dev/null
+++ b/custom/lib/zfs.sh
@@ -0,0 +1,356 @@
+#!/usr/bin/env bash
+# zfs.sh - ZFS-specific functions for archangel installer
+# Source this file after common.sh, config.sh, disk.sh
+
+#############################
+# ZFS Constants
+#############################
+
+POOL_NAME="${POOL_NAME:-zroot}"
+ASHIFT="${ASHIFT:-12}"
+COMPRESSION="${COMPRESSION:-zstd}"
+
+#############################
+# ZFS Pre-flight
+#############################
+
+zfs_preflight() {
+    # Check ZFS module
+    if ! lsmod | grep -q zfs; then
+        info "Loading ZFS module..."
+        modprobe zfs || error "Failed to load ZFS module. Is zfs-linux-lts installed?"
+    fi
+    info "ZFS module loaded successfully."
+}
+
+#############################
+# ZFS Pool Creation
+#############################
+
+create_zfs_pool() {
+    local encryption="${1:-true}"
+    local passphrase="$2"
+
+    step "Creating ZFS Pool"
+
+    # Destroy existing pool if present
+    if zpool list "$POOL_NAME" &>/dev/null; then
+        warn "Pool $POOL_NAME already exists. Destroying..."
+        zpool destroy -f "$POOL_NAME"
+    fi
+
+    # Get root partitions
+    local zfs_parts=()
+    for disk in "${SELECTED_DISKS[@]}"; do
+        zfs_parts+=("$(get_root_partition "$disk")")
+    done
+
+    # Build pool configuration based on RAID level
+    local pool_config
+    if [[ "$RAID_LEVEL" == "stripe" ]]; then
+        pool_config="${zfs_parts[*]}"
+        info "Creating striped pool with ${#zfs_parts[@]} disks (NO redundancy)..."
+        warn "Data loss will occur if ANY disk fails!"
+    elif [[ -n "$RAID_LEVEL" ]]; then
+        pool_config="$RAID_LEVEL ${zfs_parts[*]}"
+        info "Creating $RAID_LEVEL pool with ${#zfs_parts[@]} disks..."
+    else
+        pool_config="${zfs_parts[0]}"
+        info "Creating single-disk pool..."
+    fi
+
+    # Base pool options
+    local pool_opts=(
+        -f
+        -o ashift="$ASHIFT"
+        -o autotrim=on
+        -O acltype=posixacl
+        -O atime=off
+        -O canmount=off
+        -O compression="$COMPRESSION"
+        -O dnodesize=auto
+        -O normalization=formD
+        -O relatime=on
+        -O xattr=sa
+        -O mountpoint=none
+        -R /mnt
+    )
+
+    # Create pool (with or without encryption)
+    if [[ "$encryption" == "false" ]]; then
+        warn "Creating pool WITHOUT encryption"
+        zpool create "${pool_opts[@]}" "$POOL_NAME" $pool_config
+    else
+        info "Creating encrypted pool..."
+        echo "$passphrase" | zpool create "${pool_opts[@]}" \
+            -O encryption=aes-256-gcm \
+            -O keyformat=passphrase \
+            -O keylocation=prompt \
+            "$POOL_NAME" $pool_config
+    fi
+
+    info "ZFS pool created successfully."
+    zpool status "$POOL_NAME"
+}
+
+#############################
+# ZFS Dataset Creation
+#############################
+
+create_zfs_datasets() {
+    step "Creating ZFS Datasets"
+
+    # Root dataset container
+    zfs create -o mountpoint=none -o canmount=off "$POOL_NAME/ROOT"
+
+    # Calculate reservation (20% of pool, capped 5-20G)
+    local pool_size_bytes=$(zpool get -Hp size "$POOL_NAME" | awk '{print $3}')
+    local pool_size_gb=$((pool_size_bytes / 1024 / 1024 / 1024))
+    local reserve_gb=$((pool_size_gb / 5))
+    [[ $reserve_gb -gt 20 ]] && reserve_gb=20
+    [[ $reserve_gb -lt 5 ]] && reserve_gb=5
+
+    # Main root filesystem
+    zfs create -o mountpoint=/ -o canmount=noauto -o reservation=${reserve_gb}G "$POOL_NAME/ROOT/default"
+    zfs mount "$POOL_NAME/ROOT/default"
+
+    # Home
+    zfs create -o mountpoint=/home "$POOL_NAME/home"
+    zfs create -o mountpoint=/root "$POOL_NAME/home/root"
+
+    # Media - compression off for already-compressed files
+    zfs create -o mountpoint=/media -o compression=off "$POOL_NAME/media"
+
+    # VMs - 64K recordsize for VM disk images
+    zfs create -o mountpoint=/vms -o recordsize=64K "$POOL_NAME/vms"
+
+    # Var datasets
+    zfs create -o mountpoint=/var -o canmount=off "$POOL_NAME/var"
+    zfs create -o mountpoint=/var/log "$POOL_NAME/var/log"
+    zfs create -o mountpoint=/var/cache "$POOL_NAME/var/cache"
+    zfs create -o mountpoint=/var/lib -o canmount=off "$POOL_NAME/var/lib"
+    zfs create -o mountpoint=/var/lib/pacman "$POOL_NAME/var/lib/pacman"
+    zfs create -o mountpoint=/var/lib/docker "$POOL_NAME/var/lib/docker"
+
+    # Temp directories - excluded from snapshots
+    zfs create -o mountpoint=/var/tmp -o com.sun:auto-snapshot=false "$POOL_NAME/var/tmp"
+    zfs create -o mountpoint=/tmp -o com.sun:auto-snapshot=false "$POOL_NAME/tmp"
+    chmod 1777 /mnt/tmp /mnt/var/tmp
+
+    info "Datasets created:"
+    zfs list -r "$POOL_NAME" -o name,mountpoint,compression
+}
+
+#############################
+# ZFSBootMenu Configuration
+#############################
+
+configure_zfsbootmenu() {
+    step "Configuring ZFSBootMenu"
+
+    # Ensure hostid exists
+    if [[ ! -f /etc/hostid ]]; then
+        zgenhostid
+    fi
+    local host_id=$(hostid)
+
+    # Copy hostid to installed system
+    cp /etc/hostid /mnt/etc/hostid
+
+    # Create ZFSBootMenu directory on EFI
+    mkdir -p /mnt/efi/EFI/ZBM
+
+    # Download ZFSBootMenu release EFI binary
+    info "Downloading ZFSBootMenu..."
+    local zbm_url="https://get.zfsbootmenu.org/efi"
+    if ! curl -fsSL -o /mnt/efi/EFI/ZBM/zfsbootmenu.efi "$zbm_url"; then
+        error "Failed to download ZFSBootMenu"
+    fi
+    info "ZFSBootMenu binary installed."
+
+    # Set kernel command line on the ROOT PARENT dataset
+    local cmdline="rw loglevel=3"
+
+    # Add AMD GPU workarounds if needed
+    if lspci | grep -qi "amd.*display\|amd.*vga"; then
+        info "AMD GPU detected - adding workaround parameters"
+        cmdline="$cmdline amdgpu.pg_mask=0 amdgpu.cwsr_enable=0"
+    fi
+
+    zfs set org.zfsbootmenu:commandline="$cmdline" "$POOL_NAME/ROOT"
+    info "Kernel command line set on $POOL_NAME/ROOT"
+
+    # Set bootfs property
+    zpool set bootfs="$POOL_NAME/ROOT/default" "$POOL_NAME"
+    info "Default boot filesystem set to $POOL_NAME/ROOT/default"
+
+    # Create EFI boot entries for each disk
+    local zbm_cmdline="spl_hostid=0x${host_id} zbm.timeout=3 zbm.prefer=${POOL_NAME} zbm.import_policy=hostid"
+
+    for i in "${!SELECTED_DISKS[@]}"; do
+        local disk="${SELECTED_DISKS[$i]}"
+        local label="ZFSBootMenu"
+        if [[ ${#SELECTED_DISKS[@]} -gt 1 ]]; then
+            label="ZFSBootMenu-disk$((i+1))"
+        fi
+
+        info "Creating EFI boot entry: $label on $disk"
+        efibootmgr --create \
+            --disk "$disk" \
+            --part 1 \
+            --label "$label" \
+            --loader '\EFI\ZBM\zfsbootmenu.efi' \
+            --unicode "$zbm_cmdline" \
+            --quiet
+    done
+
+    # Set as primary boot option
+    local bootnum=$(efibootmgr | grep "ZFSBootMenu" | head -1 | grep -oP 'Boot\K[0-9A-F]+')
+    if [[ -n "$bootnum" ]]; then
+        local current_order=$(efibootmgr | grep "BootOrder" | cut -d: -f2 | tr -d ' ')
+        efibootmgr --bootorder "$bootnum,$current_order" --quiet
+        info "ZFSBootMenu set as primary boot option"
+    fi
+
+    info "ZFSBootMenu configuration complete."
+}
+
+#############################
+# ZFS Services
+#############################
+
+configure_zfs_services() {
+    step "Configuring ZFS Services"
+
+    arch-chroot /mnt systemctl enable zfs.target
+    arch-chroot /mnt systemctl disable zfs-import-cache.service
+    arch-chroot /mnt systemctl enable zfs-import-scan.service
+    arch-chroot /mnt systemctl enable zfs-mount.service
+    arch-chroot /mnt systemctl enable zfs-import.target
+
+    # Disable cachefile - we use zfs-import-scan
+    zpool set cachefile=none "$POOL_NAME"
+    rm -f /mnt/etc/zfs/zpool.cache
+
+    info "ZFS services configured."
+}
+
+#############################
+# Pacman Snapshot Hook
+#############################
+
+configure_zfs_pacman_hook() {
+    step "Configuring Pacman Snapshot Hook"
+
+    mkdir -p /mnt/etc/pacman.d/hooks
+
+    cat > /mnt/etc/pacman.d/hooks/zfs-snapshot.hook << EOF
+[Trigger]
+Operation = Upgrade
+Operation = Install
+Operation = Remove
+Type = Package
+Target = *
+
+[Action]
+Description = Creating ZFS snapshot before pacman transaction...
+When = PreTransaction
+Exec = /usr/local/bin/zfs-pre-snapshot
+EOF
+
+    cat > /mnt/usr/local/bin/zfs-pre-snapshot << 'EOF'
+#!/bin/bash
+POOL="zroot"
+DATASET="$POOL/ROOT/default"
+TIMESTAMP=$(date +%Y-%m-%d_%H-%M-%S)
+SNAPSHOT_NAME="pre-pacman_$TIMESTAMP"
+
+if zfs snapshot "$DATASET@$SNAPSHOT_NAME"; then
+    echo "Created snapshot: $DATASET@$SNAPSHOT_NAME"
+else
+    echo "Warning: Failed to create snapshot" >&2
+fi
+EOF
+
+    chmod +x /mnt/usr/local/bin/zfs-pre-snapshot
+    info "Pacman hook configured."
+}
+
+#############################
+# ZFS Tools
+#############################
+
+install_zfs_tools() {
+    step "Installing ZFS Management Tools"
+
+    # Copy ZFS management scripts
+    cp /usr/local/bin/zfssnapshot /mnt/usr/local/bin/zfssnapshot
+    cp /usr/local/bin/zfsrollback /mnt/usr/local/bin/zfsrollback
+    chmod +x /mnt/usr/local/bin/zfssnapshot
+    chmod +x /mnt/usr/local/bin/zfsrollback
+
+    info "ZFS management scripts installed: zfssnapshot, zfsrollback"
+}
+
+#############################
+# EFI Sync (Multi-disk)
+#############################
+
+sync_zfs_efi_partitions() {
+    local efi_parts=()
+    for disk in "${SELECTED_DISKS[@]}"; do
+        efi_parts+=("$(get_efi_partition "$disk")")
+    done
+
+    # Skip if only one disk
+    [[ ${#efi_parts[@]} -le 1 ]] && return
+
+    step "Syncing EFI partitions for redundancy"
+
+    local primary="${efi_parts[0]}"
+    for ((i=1; i<${#efi_parts[@]}; i++)); do
+        local secondary="${efi_parts[$i]}"
+        local tmp_mount="/tmp/efi_sync_$$"
+
+        mkdir -p "$tmp_mount"
+        mount "$secondary" "$tmp_mount"
+        rsync -a /mnt/efi/ "$tmp_mount/"
+        umount "$tmp_mount"
+        rmdir "$tmp_mount"
+
+        info "Synced EFI to $secondary"
+    done
+}
+
+#############################
+# Genesis Snapshot
+#############################
+
+create_zfs_genesis_snapshot() {
+    step "Creating Genesis Snapshot"
+
+    local snapshot_name="genesis"
+    zfs snapshot -r "$POOL_NAME@$snapshot_name"
+
+    info "Genesis snapshot created: $POOL_NAME@$snapshot_name"
+    info "You can restore to this point anytime with: zfsrollback $snapshot_name"
+}
+
+#############################
+# ZFS Cleanup
+#############################
+
+zfs_cleanup() {
+    step "Cleaning up ZFS"
+
+    # Unmount all ZFS datasets
+    zfs unmount -a 2>/dev/null || true
+
+    # Unmount EFI
+    umount /mnt/efi 2>/dev/null || true
+
+    # Export pool (important for clean import on boot)
+    zpool export "$POOL_NAME"
+
+    info "ZFS pool exported cleanly."
+}
diff --git a/docs/session-context.org b/docs/session-context.org
index fb23fb1..8275b4f 100644
--- a/docs/session-context.org
+++ b/docs/session-context.org
@@ -42,7 +42,19 @@ Analyzed ~/code/archsetup/archsetup (1852 lines) for chroot-incompatible operati
 Added [#B] task to todo.org with full implementation details.
 
 ** Files Modified This Session
-- todo.org - Added archsetup --chroot task
+- todo.org - Added archsetup --chroot task, btrfs implementation TODO
+- docs/PLAN-archangel-btrfs.org - Created implementation plan
+- docs/research-btrfs-expansion.org - Expanded testing validation checks
+
+** Implementation Progress (Phase 1.1)
+
+Created lib/ directory structure:
+- [X] custom/lib/common.sh - output, validation, fzf prompts, disk utils
+- [X] custom/lib/config.sh - arg parsing, config loading, validation
+- [X] custom/lib/disk.sh - partitioning, EFI management, disk selection
+- [X] custom/lib/zfs.sh - pool, datasets, ZFSBootMenu, services, hooks
+
+Next: Integrate libs into install-archzfs, test, then add filesystem selection
 
 ** Pending Items (from earlier + this session)
 1. Review code-review.org document