Orion O6 - Minimum Power Testing

min-power-test.sh

#!/bin/bash
# Minimum power test script for Radxa Orion O6 / CIX Sky1
# Modular design with individual power controls
# Run as root.

set -e

#=============================================================================
# Configuration
#=============================================================================
DDR_LP="/sys/devices/platform/cix_ddr_lp/on"
CPU_IPA="/sys/devices/platform/83bf0300.cix_cpu_ipa/cpu_power"
CI700_DEVFREQ="/sys/class/devfreq/cix_bus_ci700"
NI700_DEVFREQ="/sys/class/devfreq/cix_bus_ni700"

USB_CONTROLLERS="9010000 9080000 90f0000 9160000 91d0000 91e0000 9260000 9290000 92c0000 92f0000"
DISPLAY_CONTROLLERS="14010000 14080000 140f0000 14160000 141d0000"

# PCIe root ports for 5GbE R8126 controllers
PCIE_5GBE_PORTS="a0d0000.pcie a0e0000.pcie"

# PCIe root port for WiFi (RTL8852BE)
PCIE_WIFI_PORT="a0c0000.pcie"

# PCIe root port for NVMe
PCIE_NVME_PORT="a070000.pcie"

# Ramdisk location - MUST be on existing tmpfs (not under root fs)
RAMROOT="/run/ramroot"

#=============================================================================
# Utility Functions
#=============================================================================
hold_for() {
    local secs=$1 label=$2
    echo ">>> $label - hold ${secs}s ($(date '+%H:%M:%S'))"
    for i in $(seq $secs -1 1); do
        printf "\r    %3d seconds..." $i
        sleep 1
    done
    echo ""
}

#=============================================================================
# Individual Power Controls (on/off functions)
#=============================================================================

# --- GDM / Desktop ---
ctl_gdm() {
    case $1 in
        off)
            systemctl stop gdm 2>/dev/null || true
            pkill -9 gnome-shell 2>/dev/null || true
            pkill -9 Xwayland 2>/dev/null || true
            pkill -9 gsd- 2>/dev/null || true
            sleep 2
            echo "  GDM/desktop: stopped"
            ;;
        on)
            systemctl start gdm 2>/dev/null || true
            echo "  GDM/desktop: started"
            ;;
    esac
}

# --- GPU (panthor) ---
ctl_gpu() {
    case $1 in
        off)
            rmmod panthor 2>/dev/null && echo "  GPU: unloaded" || echo "  GPU: already unloaded"
            ;;
        on)
            modprobe panthor 2>/dev/null || true
            if [ ! -e "/sys/devices/platform/soc@0/15000000.gpu/driver" ]; then
                echo "15000000.gpu" > /sys/bus/platform/drivers/panthor/bind 2>/dev/null || true
            fi
            echo "  GPU: loaded"
            ;;
    esac
}

# --- Display (DPU + DP TX) ---
ctl_display() {
    case $1 in
        off)
            rmmod trilin_dpsub 2>/dev/null || true
            rmmod linlon_dp 2>/dev/null || true
            echo "  Display: unloaded"
            ;;
        on)
            modprobe linlon_dp 2>/dev/null || true
            modprobe trilin_dpsub 2>/dev/null || true
            for disp in $DISPLAY_CONTROLLERS; do
                if [ ! -e "/sys/bus/platform/drivers/linlondp/${disp}.disp-controller" ]; then
                    echo "${disp}.disp-controller" > /sys/bus/platform/drivers/linlondp/bind 2>/dev/null || true
                fi
            done
            echo "  Display: loaded"
            ;;
    esac
}

# --- WiFi ---
ctl_wifi() {
    local deep=${2:-false}  # "deep" = also remove PCI device
    case $1 in
        off)
            /usr/sbin/rfkill block wifi 2>/dev/null || true
            ip link set wlp97s0 down 2>/dev/null || true
            rmmod rtw89_8852be rtw89_8852b rtw89_8852b_common rtw89_pci rtw89_core 2>/dev/null || true
            rmmod mac80211 cfg80211 2>/dev/null || true
            if [ "$deep" = "deep" ]; then
                # Remove WiFi PCI device (RTL8852BE = 10ec:b852)
                for dev in /sys/bus/pci/devices/*; do
                    vendor=$(cat "$dev/vendor" 2>/dev/null)
                    device=$(cat "$dev/device" 2>/dev/null)
                    if [ "$vendor" = "0x10ec" ] && [ "$device" = "0xb852" ]; then
                        echo 1 > "$dev/remove" 2>/dev/null || true
                        echo "  WiFi: disabled + PCI device removed"
                        return
                    fi
                done
                echo "  WiFi: disabled (device already removed)"
            else
                echo "  WiFi: disabled"
            fi
            ;;
        on)
            # Rescan to restore removed device
            echo 1 > /sys/bus/pci/rescan 2>/dev/null || true
            sleep 1
            modprobe rtw89_8852be 2>/dev/null || true
            /usr/sbin/rfkill unblock wifi 2>/dev/null || true
            echo "  WiFi: enabled"
            ;;
    esac
}

# --- Bluetooth ---
ctl_bluetooth() {
    case $1 in
        off)
            /usr/sbin/rfkill block bluetooth 2>/dev/null || true
            rmmod btusb btrtl btintel btbcm btmtk 2>/dev/null || true
            echo "  Bluetooth: disabled"
            ;;
        on)
            modprobe btusb 2>/dev/null || true
            /usr/sbin/rfkill unblock bluetooth 2>/dev/null || true
            echo "  Bluetooth: enabled"
            ;;
    esac
}

# --- USB Controllers ---
ctl_usb() {
    local keep=${2:-}  # optional controller to keep
    case $1 in
        off)
            for usb in $USB_CONTROLLERS; do
                [ "$usb" = "$keep" ] && continue
                if [ -e "/sys/bus/platform/drivers/cdns-usbssp/${usb}.usb-controller" ]; then
                    echo "${usb}.usb-controller" > /sys/bus/platform/drivers/cdns-usbssp/unbind 2>/dev/null || true
                fi
            done
            echo "  USB: unbound${keep:+ (kept $keep)}"
            ;;
        on)
            for usb in $USB_CONTROLLERS; do
                if [ ! -e "/sys/bus/platform/drivers/cdns-usbssp/${usb}.usb-controller" ]; then
                    echo "${usb}.usb-controller" > /sys/bus/platform/drivers/cdns-usbssp/bind 2>/dev/null || true
                fi
            done
            echo "  USB: bound"
            ;;
    esac
}

# --- Audio ---
ctl_audio() {
    case $1 in
        off)
            rmmod snd_hda_codec_alc269 snd_hda_scodec_component snd_hda_codec_realtek_lib 2>/dev/null || true
            rmmod snd_hda_codec_generic snd_hda_cix_ipbloq snd_hda_codec snd_hda_core 2>/dev/null || true
            rmmod snd_soc_hdmi_codec snd_soc_sky1_card snd_soc_cdns_i2s_mc snd_soc_core 2>/dev/null || true
            rmmod snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd soundcore 2>/dev/null || true
            if [ -e "/sys/bus/platform/drivers/arm-dma350/7010000.dma-controller" ]; then
                echo "7010000.dma-controller" > /sys/bus/platform/drivers/arm-dma350/unbind 2>/dev/null || true
            fi
            echo "  Audio: unloaded"
            ;;
        on)
            modprobe snd_hda_cix_ipbloq 2>/dev/null || true
            echo "  Audio: loaded (may need reboot)"
            ;;
    esac
}

# --- PCIe ASPM ---
ctl_pcie_aspm() {
    case $1 in
        off)  # powersupersave
            echo powersupersave > /sys/module/pcie_aspm/parameters/policy 2>/dev/null || true
            for d in /sys/bus/pci/devices/*/power/control; do
                echo auto > "$d" 2>/dev/null || true
            done
            # L1 substates
            setpci -s 0001:90:00.0 0x908.b=0x0f 2>/dev/null || true
            setpci -s 0001:91:00.0 0x230.b=0x0f 2>/dev/null || true
            setpci -s 0000:60:00.0 0x908.b=0x0f 2>/dev/null || true
            setpci -s 0002:30:00.0 0x908.b=0x0f 2>/dev/null || true
            setpci -s 0002:31:00.0 0x22c.b=0x0f 2>/dev/null || true
            setpci -s 0003:00:00.0 0x908.b=0x0f 2>/dev/null || true
            setpci -s 0003:01:00.0 0x22c.b=0x0f 2>/dev/null || true
            echo "  PCIe ASPM: powersupersave + L1 substates"
            ;;
        on)  # default
            echo default > /sys/module/pcie_aspm/parameters/policy 2>/dev/null || true
            echo "  PCIe ASPM: default"
            ;;
    esac
}

# --- DDR Low Power ---
# Note: "on" = LP enabled (low power), "off" = LP disabled (full performance)
ctl_ddr_lp() {
    case $1 in
        on)  # enable LP mode (low power)
            [ -f "$DDR_LP" ] && echo 1 > "$DDR_LP"
            echo "  DDR LP: enabled (low power)"
            ;;
        off)  # disable LP mode (full performance)
            [ -f "$DDR_LP" ] && echo 0 > "$DDR_LP"
            echo "  DDR LP: disabled (full performance)"
            ;;
    esac
}

# --- Bus Frequency ---
ctl_bus_freq() {
    local mode=$1  # min or max
    [ ! -d "$CI700_DEVFREQ" ] && return
    [ ! -d "$NI700_DEVFREQ" ] && return

    local ci_freqs=$(cat "$CI700_DEVFREQ/available_frequencies")
    local ni_freqs=$(cat "$NI700_DEVFREQ/available_frequencies")

    if [ "$mode" = "min" ]; then
        local ci_freq=$(echo $ci_freqs | awk '{print $1}')
        local ni_freq=$(echo $ni_freqs | awk '{print $1}')
    else
        local ci_freq=$(echo $ci_freqs | awk '{print $NF}')
        local ni_freq=$(echo $ni_freqs | awk '{print $NF}')
    fi

    echo "$ci_freq" > "$CI700_DEVFREQ/min_freq"
    echo "$ci_freq" > "$CI700_DEVFREQ/max_freq"
    echo "$ni_freq" > "$NI700_DEVFREQ/min_freq"
    echo "$ni_freq" > "$NI700_DEVFREQ/max_freq"
    echo "  Bus freq: CI-700=$((ci_freq/1000000))MHz NI-700=$((ni_freq/1000000))MHz"
}

# --- CPU ---
ctl_cpu() {
    case $1 in
        off)  # powersave, single core
            for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
                echo powersave > "$cpu" 2>/dev/null || true
            done
            for cpu in /sys/devices/system/cpu/cpu{1..11}/online; do
                echo 0 > "$cpu" 2>/dev/null || true
            done
            echo "  CPU: powersave, 1 core online"
            ;;
        on)  # schedutil, all cores
            for cpu in /sys/devices/system/cpu/cpu{1..11}/online; do
                echo 1 > "$cpu" 2>/dev/null || true
            done
            for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
                echo schedutil > "$cpu" 2>/dev/null || true
            done
            for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq; do
                max=$(cat $(dirname $cpu)/scaling_available_frequencies 2>/dev/null | awk '{print $NF}')
                [ -n "$max" ] && echo "$max" > "$cpu" 2>/dev/null || true
            done
            echo "  CPU: schedutil, all cores online"
            ;;
    esac
}

# --- Misc modules ---
ctl_misc() {
    case $1 in
        off)
            rmmod goodix_ts 2>/dev/null || true
            rmmod cix_dsp_rproc 2>/dev/null || true
            echo "  Misc: unloaded (touchscreen, DSP)"
            ;;
        on)
            modprobe goodix_ts 2>/dev/null || true
            modprobe cix_dsp_rproc 2>/dev/null || true
            echo "  Misc: loaded"
            ;;
    esac
}

# --- 5GbE R8126 (remove PCI devices) ---
# Note: We use PCI device removal since sky1-pcie driver lacks bind/unbind sysfs.
# To restore after removal, need to rescan the bus or reboot.
ctl_5gbe() {
    case $1 in
        off)
            # Find and remove R8126 devices (vendor:device = 10ec:8126)
            for dev in /sys/bus/pci/devices/*; do
                vendor=$(cat "$dev/vendor" 2>/dev/null)
                device=$(cat "$dev/device" 2>/dev/null)
                if [ "$vendor" = "0x10ec" ] && [ "$device" = "0x8126" ]; then
                    echo 1 > "$dev/remove" 2>/dev/null || true
                    echo "  Removed $(basename $dev)"
                fi
            done
            echo "  5GbE: R8126 devices removed from bus"
            ;;
        on)
            # Rescan PCIe buses to re-enumerate removed devices
            echo 1 > /sys/bus/pci/rescan 2>/dev/null || true
            echo "  5GbE: PCIe bus rescanned"
            ;;
    esac
}

# --- PMU (Performance Monitoring Units - not needed for headless) ---
# NOTE: cix_pmu is used by devfreq for bus frequency scaling.
# We must stop devfreq polling before unloading it, or the kernel crashes.
ctl_pmu() {
    case $1 in
        off)
            # Stop devfreq polling first to prevent use-after-free crash
            for gov in "$CI700_DEVFREQ/governor" "$NI700_DEVFREQ/governor"; do
                [ -f "$gov" ] && echo "userspace" > "$gov" 2>/dev/null || true
            done
            sleep 0.5  # Let devfreq workqueue drain
            rmmod arm_cmn arm_dsu_pmu 2>/dev/null || true
            # cix_pmu is too dangerous to unload - tied to devfreq events
            # rmmod cix_pmu 2>/dev/null || true
            echo "  PMU: unloaded (arm_cmn, arm_dsu_pmu) - cix_pmu kept for devfreq"
            ;;
        on)
            modprobe arm_cmn 2>/dev/null || true
            modprobe arm_dsu_pmu 2>/dev/null || true
            # Restore devfreq governor
            for gov in "$CI700_DEVFREQ/governor" "$NI700_DEVFREQ/governor"; do
                [ -f "$gov" ] && echo "simple_ondemand" > "$gov" 2>/dev/null || true
            done
            echo "  PMU: loaded"
            ;;
    esac
}

#=============================================================================
# High-Level Commands
#=============================================================================

usage() {
    echo "Usage: $0 <command> [options]"
    echo ""
    echo "Commands:"
    echo "  status              - Show current power-related settings"
    echo "  baseline            - Set known HIGH power state for measurement"
    echo "  apply               - Apply power savings (keeps display)"
    echo "  headless            - Maximum power savings (serial only!)"
    echo "  restore             - Restore normal operation"
    echo "  benchmark           - Run memory bandwidth test at different bus frequencies"
    echo "  powertest [secs]    - Bus frequency power test (default 30s holds)"
    echo "  powersteps [secs]   - Step-by-step power test (default 20s holds)"
    echo "  ramtest [secs]      - Pivot to ramdisk, disable NVMe (default 60s hold)"
    echo ""
    echo "Individual controls (for testing):"
    echo "  ctl <name> <on|off> - Control individual subsystem"
    echo "  Names: gdm, gpu, display, wifi, bluetooth, usb, audio, pcie, ddr, bus, cpu, misc, 5gbe, pmu"
    exit 1
}

show_status() {
    echo "=== Power Status ==="
    echo ""
    echo "CPU: $(cat /sys/devices/system/cpu/online) online, $(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor 2>/dev/null) governor"

    if [ -d "$CI700_DEVFREQ" ]; then
        echo "CI-700: $(( $(cat $CI700_DEVFREQ/cur_freq) / 1000000 )) MHz"
    fi
    if [ -d "$NI700_DEVFREQ" ]; then
        echo "NI-700: $(( $(cat $NI700_DEVFREQ/cur_freq) / 1000000 )) MHz"
    fi

    [ -f "$DDR_LP" ] && echo "DDR LP: $([ $(cat $DDR_LP) = 1 ] && echo enabled || echo disabled)"
    echo "PCIe ASPM: $(cat /sys/module/pcie_aspm/parameters/policy)"

    echo ""
    echo "GPU: $([ -e /sys/devices/platform/soc@0/15000000.gpu/driver ] && echo bound || echo unbound)"
    echo "Display: $(lsmod | grep -q linlon_dp && echo loaded || echo unloaded)"
    echo "WiFi: $(/usr/sbin/rfkill list wifi 2>/dev/null | grep -q 'Soft blocked: yes' && echo blocked || echo unblocked)"
    echo "Bluetooth: $(/usr/sbin/rfkill list bluetooth 2>/dev/null | grep -q 'Soft blocked: yes' && echo blocked || echo unblocked)"

    local usb_bound=0
    for usb in $USB_CONTROLLERS; do
        [ -e "/sys/bus/platform/drivers/cdns-usbssp/${usb}.usb-controller" ] && usb_bound=$((usb_bound + 1))
    done
    echo "USB: $usb_bound/10 controllers bound"
}

set_baseline() {
    echo "=== Setting HIGH Power Baseline ==="
    echo ""
    echo "This sets all subsystems to maximum power state"
    echo "for accurate power savings measurements."
    echo ""

    # Ensure all CPUs online and at max performance
    echo "CPUs: all online, performance governor..."
    for cpu in /sys/devices/system/cpu/cpu{1..11}/online; do
        echo 1 > "$cpu" 2>/dev/null || true
    done
    for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
        echo performance > "$cpu" 2>/dev/null || true
    done
    for cpu in /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq; do
        max=$(cat $(dirname $cpu)/scaling_available_frequencies 2>/dev/null | awk '{print $NF}')
        [ -n "$max" ] && echo "$max" > "$cpu" 2>/dev/null || true
    done

    # Bus frequencies to MAX
    echo "Bus freq: MAX..."
    ctl_bus_freq max

    # DDR LP disabled (full performance)
    echo "DDR LP: disabled (full performance)..."
    ctl_ddr_lp off

    # PCIe ASPM off (default policy)
    echo "PCIe ASPM: default..."
    ctl_pcie_aspm on

    # Ensure all USB controllers bound
    echo "USB: binding all controllers..."
    ctl_usb on

    # Ensure display/GPU loaded
    echo "Display/GPU: loading..."
    ctl_display on
    ctl_gpu on

    # WiFi/BT unblocked
    echo "WiFi/Bluetooth: unblocking..."
    ctl_wifi on
    ctl_bluetooth on

    echo ""
    echo "=== Baseline Set ==="
    show_status
    echo ""
    echo "System is now at MAXIMUM power state."
    echo "Wait 10-20s for power to stabilize before measuring."
}

apply_power_savings() {
    local headless=${1:-false}
    local skip_confirm=${2:-false}

    echo "=== Applying Power Savings ==="
    [ "$headless" = "true" ] && echo "MODE: HEADLESS" || echo "MODE: WITH DISPLAY"

    if [ "$skip_confirm" != "true" ]; then
        read -p "Continue? [y/N] " -n 1 -r
        echo
        [[ ! $REPLY =~ ^[Yy]$ ]] && exit 1
    fi

    ctl_gdm off
    [ "$headless" = "true" ] && ctl_gpu off
    [ "$headless" = "true" ] && ctl_display off
    [ "$headless" = "true" ] && ctl_wifi off deep || ctl_wifi off
    ctl_bluetooth off
    [ "$headless" = "true" ] && ctl_usb off || ctl_usb off 9260000
    ctl_audio off
    ctl_5gbe off
    ctl_pmu off
    ctl_pcie_aspm off
    ctl_ddr_lp on
    ctl_bus_freq min
    ctl_cpu off
    ctl_misc off

    echo ""
    echo "=== MINIMUM POWER MODE ACTIVE ==="
    echo "To restore: $0 restore"
}

restore_normal() {
    echo "=== Restoring Normal Operation ==="

    ctl_cpu on
    ctl_bus_freq max
    ctl_ddr_lp on  # Keep LP enabled - it's automatic
    ctl_pcie_aspm on
    ctl_pmu on
    ctl_5gbe on
    ctl_misc on
    ctl_audio on
    ctl_usb on
    ctl_bluetooth on
    ctl_wifi on
    ctl_display on
    ctl_gpu on
    ctl_gdm on

    echo ""
    echo "=== Normal Operation Restored ==="
}

powersteps() {
    local hold=${1:-20}

    echo "=========================================="
    echo "=== Step-by-Step Power Measurement ==="
    echo "=========================================="
    echo "Hold time: ${hold}s per step"
    echo ""
    echo "This will:"
    echo "  1. Set HIGH power baseline (buses MAX, DDR LP off, all CPUs)"
    echo "  2. Step through each power saving with ${hold}s holds"
    echo ""
    read -p "Continue? [y/N] " -n 1 -r
    echo
    [[ ! $REPLY =~ ^[Yy]$ ]] && exit 1

    # Set known high-power baseline first
    set_baseline
    echo ""
    hold_for $hold "BASELINE (max power)"

    ctl_gdm off
    hold_for $hold "GDM stopped"

    ctl_gpu off
    hold_for $hold "GPU unloaded"

    ctl_display off
    hold_for $hold "Display unloaded"

    ctl_wifi off deep
    hold_for $hold "WiFi disabled + PCIe unbound"

    ctl_bluetooth off
    hold_for $hold "Bluetooth disabled"

    ctl_usb off
    hold_for $hold "USB unbound"

    ctl_audio off
    hold_for $hold "Audio unloaded"

    ctl_5gbe off
    hold_for $hold "5GbE PCIe ports unbound"

    ctl_pmu off
    hold_for $hold "PMU modules unloaded"

    ctl_pcie_aspm off
    hold_for $hold "PCIe ASPM powersupersave"

    ctl_ddr_lp on
    hold_for $hold "DDR LP enabled"

    ctl_bus_freq min
    hold_for $hold "Bus freq MIN"

    ctl_cpu off
    hold_for $hold "CPU powersave + 1 core"

    echo ""
    echo "=== All steps complete ==="
    echo "System at minimum power. To restore: $0 restore"
}

powertest() {
    local duration=${1:-30}

    echo "=== Bus Frequency Power Test ==="
    echo "Duration: ${duration}s per phase"
    read -p "Continue? [y/N] " -n 1 -r
    echo
    [[ ! $REPLY =~ ^[Yy]$ ]] && exit 1

    apply_power_savings true true
    echo ""
    echo "Stabilizing for 10s..."
    sleep 10

    [ ! -d "$CI700_DEVFREQ" ] && { echo "ERROR: devfreq not available"; exit 1; }

    local ci_freqs=$(cat "$CI700_DEVFREQ/available_frequencies")
    local ni_freqs=$(cat "$NI700_DEVFREQ/available_frequencies")
    local ci_min=$(echo $ci_freqs | awk '{print $1}')
    local ci_max=$(echo $ci_freqs | awk '{print $NF}')
    local ni_min=$(echo $ni_freqs | awk '{print $1}')
    local ni_max=$(echo $ni_freqs | awk '{print $NF}')

    trap 'echo "Interrupted"; restore_normal; exit 0' INT TERM

    ctl_bus_freq min
    hold_for $duration "Phase 1: MIN/MIN"

    ctl_bus_freq max
    hold_for $duration "Phase 2: MAX/MAX"

    echo "$ci_max" > "$CI700_DEVFREQ/min_freq"; echo "$ci_max" > "$CI700_DEVFREQ/max_freq"
    echo "$ni_min" > "$NI700_DEVFREQ/min_freq"; echo "$ni_min" > "$NI700_DEVFREQ/max_freq"
    hold_for $duration "Phase 3: CI MAX, NI MIN"

    echo "$ci_min" > "$CI700_DEVFREQ/min_freq"; echo "$ci_min" > "$CI700_DEVFREQ/max_freq"
    echo "$ni_max" > "$NI700_DEVFREQ/min_freq"; echo "$ni_max" > "$NI700_DEVFREQ/max_freq"
    hold_for $duration "Phase 4: CI MIN, NI MAX"

    restore_normal
    echo "=== Power test complete ==="
}

benchmark() {
    echo "=== Memory Bandwidth Benchmark ==="
    [ ! -d "$CI700_DEVFREQ" ] && { echo "ERROR: devfreq not available"; exit 1; }

    local ci_freqs=$(cat "$CI700_DEVFREQ/available_frequencies")
    local ni_freqs=$(cat "$NI700_DEVFREQ/available_frequencies")
    local ci_min=$(echo $ci_freqs | awk '{print $1}')
    local ci_max=$(echo $ci_freqs | awk '{print $NF}')
    local ni_min=$(echo $ni_freqs | awk '{print $1}')
    local ni_max=$(echo $ni_freqs | awk '{print $NF}')

    run_bw() {
        sync; echo 3 > /proc/sys/vm/drop_caches 2>/dev/null || true
        dd if=/dev/zero of=/dev/null bs=1M count=2048 2>&1 | tail -1 | grep -oP '[\d.]+\s*[GM]B/s' || echo "N/A"
    }

    echo ""
    echo "MAX frequencies:"
    ctl_bus_freq max
    sleep 1
    echo "  Bandwidth: $(run_bw)"

    echo ""
    echo "MIN frequencies:"
    ctl_bus_freq min
    sleep 1
    echo "  Bandwidth: $(run_bw)"

    ctl_bus_freq max
    echo ""
    echo "=== Benchmark complete ==="
}

#=============================================================================
# Ramdisk Power Test (pivot root, disable NVMe)
#=============================================================================

setup_ramroot() {
    echo "Setting up ramdisk root..."

    # Use existing tmpfs (/run is already tmpfs)
    # Don't mount a new one - just create directory
    mkdir -p "$RAMROOT"

    # Create directory structure
    mkdir -p "$RAMROOT"/{bin,sbin,proc,sys,dev,tmp,oldroot}
    mkdir -p "$RAMROOT"/sys/bus/platform/drivers/sky1-pcie
    mkdir -p "$RAMROOT"/sys/class/devfreq
    mkdir -p "$RAMROOT"/sys/devices/system/cpu
    mkdir -p "$RAMROOT"/sys/devices/platform

    # Copy busybox and create symlinks
    cp /bin/busybox "$RAMROOT/bin/"
    for cmd in sh ash cat echo sleep ls mkdir mount umount sync \
               grep awk sed tr head tail printf date seq chroot; do
        ln -sf busybox "$RAMROOT/bin/$cmd"
    done

    # Copy this script
    cp "$0" "$RAMROOT/bin/power.sh"
    chmod +x "$RAMROOT/bin/power.sh"

    # Create restore script
    cat > "$RAMROOT/bin/restore.sh" << 'RESTORE_EOF'
#!/bin/busybox sh
# Restore NVMe and pivot back to real root

echo "=== Restoring NVMe and root filesystem ==="

# Rescan PCI bus to re-enumerate NVMe
echo "  Rescanning PCI bus..."
echo 1 > /sys/bus/pci/rescan 2>/dev/null
sleep 2

# Wait for NVMe to appear
echo "  Waiting for NVMe..."
for i in $(seq 1 15); do
    [ -b /dev/nvme0n1p3 ] && break
    sleep 1
    echo "    $i..."
done

if [ ! -b /dev/nvme0n1p3 ]; then
    echo "ERROR: NVMe device not found!"
    echo "Try: echo 1 > /sys/bus/pci/rescan"
    echo "Then: mount /dev/nvme0n1p3 /oldroot"
    exit 1
fi

# Mount old root
mount /dev/nvme0n1p3 /oldroot
if [ $? -ne 0 ]; then
    echo "ERROR: Failed to mount root filesystem!"
    exit 1
fi

echo "  Root filesystem mounted"

# Pivot back
cd /oldroot
mount --move /sys /oldroot/sys
mount --move /proc /oldroot/proc
mount --move /dev /oldroot/dev

pivot_root . tmp/ramroot
exec chroot . /bin/sh -c 'umount /tmp/ramroot 2>/dev/null; exec /bin/bash'
RESTORE_EOF
    chmod +x "$RAMROOT/bin/restore.sh"

    echo "  Ramdisk ready at $RAMROOT"
}

pivot_to_ramroot() {
    echo "Switching to ramdisk environment..."

    # Sync filesystems
    sync

    # We don't do a full pivot_root (complex requirements).
    # Instead, we'll lazy unmount root and remove NVMe.
    # The kernel keeps pages in memory until all refs are gone.

    # Make sure we're running from ramdisk copy
    if [ ! -f "$RAMROOT/bin/busybox" ]; then
        echo "ERROR: Ramdisk not set up properly"
        return 1
    fi

    # Pre-cache binaries we'll need after unmount
    # This loads them into page cache so they stay available
    date +%s >/dev/null 2>&1
    seq 1 1 >/dev/null 2>&1
    printf "" 2>&1
    sleep 0.01 2>&1
    lspci >/dev/null 2>&1

    # Export for subshells
    export PATH="$RAMROOT/bin:$PATH"
    export RAMROOT

    echo "  Ramdisk environment ready"
    echo "  Binaries pre-cached for post-unmount operation"
}

stop_background_services() {
    echo "Aggressively stopping all services and freezing system..."

    # Mask services so systemd won't try to restart them
    systemctl mask --runtime systemd-journald rpcbind nfs-server \
        irqbalance cron cups avahi-daemon ModemManager NetworkManager \
        wpa_supplicant polkit accounts-daemon udisks2 colord thermald \
        packagekit rsyslog 2>/dev/null || true

    # Stop all non-essential services
    systemctl stop irqbalance cron cups rpcbind avahi-daemon \
        ModemManager NetworkManager wpa_supplicant polkit \
        accounts-daemon udisks2 colord thermald packagekit \
        nfs-server nfs-mountd nfs-idmapd 2>/dev/null || true

    # Stop logging
    systemctl stop systemd-journald rsyslog 2>/dev/null || true

    # Kill absolutely everything except essential processes
    # Get our own PID and parent PIDs to avoid killing ourselves
    local my_pid=$$
    local my_ppid=$(ps -o ppid= -p $my_pid | tr -d ' ')

    # Kill all user processes
    pkill -9 -u radxa 2>/dev/null || true

    # Kill specific troublemakers
    pkill -9 gvfsd gvfs dconf at-spi ibus evolution tracker gmain 2>/dev/null || true
    pkill -9 -f "/usr/lib" 2>/dev/null || true

    # Send SIGSTOP to all processes except our shell and kernel threads
    echo "  Freezing remaining processes..."
    for pid in $(ps -eo pid= | tr -d ' '); do
        # Skip kernel threads (ppid=2), our process, and PID 1
        [ "$pid" = "1" ] && continue
        [ "$pid" = "2" ] && continue
        [ "$pid" = "$my_pid" ] && continue
        [ "$pid" = "$my_ppid" ] && continue
        ppid=$(ps -o ppid= -p $pid 2>/dev/null | tr -d ' ')
        [ "$ppid" = "2" ] && continue  # kernel thread
        kill -STOP $pid 2>/dev/null || true
    done

    echo "  All processes frozen"
}

unmount_nvme() {
    echo "Unmounting NVMe filesystem..."

    # Sync and drop caches first
    sync
    echo 3 > /proc/sys/vm/drop_caches 2>/dev/null || true

    # Lazy unmount the old root
    umount -l /oldroot 2>/dev/null || true

    echo "  NVMe unmounted"
}

unbind_nvme_pcie() {
    echo "Removing NVMe from PCI bus..."

    # Find and remove NVMe device (class 0108 = Non-Volatile memory controller)
    for dev in /sys/bus/pci/devices/*; do
        class=$(cat "$dev/class" 2>/dev/null)
        # Class 0x010802 = NVMe controller
        if [ "${class:0:6}" = "0x0108" ]; then
            devname=$(basename $dev)
            echo 1 > "$dev/remove" 2>/dev/null || true
            echo "  NVMe removed: $devname"
            return
        fi
    done
    echo "  NVMe device not found (already removed?)"
}

ramtest() {
    local duration=${1:-60}

    echo "=========================================="
    echo "=== RAMDISK POWER TEST ==="
    echo "=========================================="
    echo ""
    echo "This will:"
    echo "  1. Apply all power savings (headless mode)"
    echo "  2. Lazy-unmount root filesystem"
    echo "  3. Remove NVMe from PCI bus"
    echo "  4. Hold for ${duration}s for measurement"
    echo "  5. Restore NVMe (rescan PCI bus)"
    echo ""
    echo "WARNING: This is experimental! Have serial console ready."
    echo "         If something goes wrong, you'll need to reboot."
    echo ""
    read -p "Continue? [y/N] " -n 1 -r
    echo
    [[ ! $REPLY =~ ^[Yy]$ ]] && exit 1

    # Step 1: Setup ramdisk while we still have full system
    setup_ramroot

    # Step 2: Apply power savings (except NVMe-related)
    echo ""
    echo "=== Applying power savings ==="
    ctl_gdm off
    ctl_gpu off
    ctl_display off
    ctl_wifi off deep
    ctl_bluetooth off
    ctl_usb off
    ctl_audio off
    ctl_5gbe off
    ctl_pmu off
    ctl_pcie_aspm off
    ctl_ddr_lp on
    ctl_bus_freq min
    ctl_cpu off
    ctl_misc off

    echo ""
    echo "=== Preparing ramdisk ==="
    pivot_to_ramroot

    echo ""
    echo "=== Stopping background services ==="
    stop_background_services

    echo ""
    echo "=== Disabling NVMe ==="
    unmount_nvme
    unbind_nvme_pcie

    echo ""
    echo "=========================================="
    echo "=== MINIMUM POWER - NVMe REMOVED ==="
    echo "=========================================="
    echo "All subsystems disabled including NVMe."
    echo "Root filesystem lazy-unmounted (cached in RAM)."
    echo ""
    echo ">>> Measure power now!"
    echo ""
    echo "Press ENTER to restore NVMe and exit..."
    read dummy

    echo ""
    echo "=== Restoring NVMe ==="
    echo 1 > /sys/bus/pci/rescan 2>/dev/null || true
    # Use bash built-in for delay (read with timeout)
    read -t 3 dummy 2>/dev/null || true

    # NVMe should be back after rescan
    echo "  PCI rescan complete"
    echo ""
    echo "=========================================="
    echo "Test complete. Please REBOOT to restore system."
    echo "=========================================="
}

#=============================================================================
# Main
#=============================================================================

case "${1:-}" in
    status)     show_status ;;
    baseline)   set_baseline ;;
    apply)      apply_power_savings false ;;
    headless)   apply_power_savings true ;;
    restore)    restore_normal ;;
    benchmark)  benchmark ;;
    powertest)  powertest "${2:-30}" ;;
    powersteps) powersteps "${2:-20}" ;;
    ramtest)    ramtest "${2:-60}" ;;
    ctl)
        { [ -z "$2" ] || [ -z "$3" ]; } && { echo "Usage: $0 ctl <name> <on|off>"; exit 1; }
        case "$2" in
            gdm)       ctl_gdm "$3" ;;
            gpu)       ctl_gpu "$3" ;;
            display)   ctl_display "$3" ;;
            wifi)      ctl_wifi "$3" ;;
            bluetooth) ctl_bluetooth "$3" ;;
            usb)       ctl_usb "$3" ;;
            audio)     ctl_audio "$3" ;;
            pcie)      ctl_pcie_aspm "$3" ;;
            ddr)       ctl_ddr_lp "$3" ;;
            bus)       ctl_bus_freq "$3" ;;  # min/max instead of on/off
            cpu)       ctl_cpu "$3" ;;
            misc)      ctl_misc "$3" ;;
            5gbe)      ctl_5gbe "$3" ;;
            pmu)       ctl_pmu "$3" ;;
            *)         echo "Unknown: $2"; exit 1 ;;
        esac
        ;;
    *)          usage ;;
esac