setup-undervolt.sh

#!/usr/bin/env bash
set -euo pipefail

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
BOLD='\033[1m'
DIM='\033[2m'
NC='\033[0m'

die() { echo -e "${RED}FATAL: $*${NC}" >&2; exit 1; }

[[ $EUID -eq 0 ]] || die "Run with sudo: sudo $0"

SERVICE_FILE="/etc/systemd/system/cpu-undervolt.service"
STATE_FILE="/etc/cpu-undervolt-state"
BASHRC="$( eval echo ~${SUDO_USER:-$USER} )/.bashrc"

echo -e "\n${BOLD}=== Undervolt Setup ===${NC}\n"

# ---- 1. Add power function to bashrc ----------------------------------------
echo -e "${CYAN}[1/2] Adding 'power' command to bashrc...${NC}"

# Remove ALL old versions
while grep -q '# --- power: CPU undervolt manager' "$BASHRC" 2>/dev/null; do
    sed -i '/^# --- power: CPU undervolt manager/,/^# --- end power ---$/d' "$BASHRC"
    sed -i '/^# --- power: CPU undervolt manager/,/^}$/d' "$BASHRC"
done
sed -i '/^# --- end power ---$/d' "$BASHRC"

cat >> "$BASHRC" << 'ENDFUNC'
# --- power: CPU undervolt manager + system power stats ---
power() {
    local RED="\033[0;31m" GREEN="\033[0;32m" YELLOW="\033[1;33m"
    local CYAN="\033[0;36m" BOLD="\033[1m" DIM="\033[2m" NC="\033[0m"

    _power_encode_msr() {
        local plane=$1 mv=$2
        local offset_1024=$(( (mv * 1024 + 500) / 1000 ))
        if (( mv < 0 )); then
            offset_1024=$(( (mv * 1024 - 500) / 1000 ))
        fi
        local masked=$(( offset_1024 & 0x7FF ))
        local value=$(( 0x8000001100000000 | (plane << 40) | (masked << 21) ))
        printf "0x%016X" "$value"
    }

    if [[ "${1:-}" == "-reset" ]]; then
        echo -e "\n${BOLD}Resetting undervolt to 0mV...${NC}"
        sudo bash -c 'modprobe msr 2>/dev/null; wrmsr -a 0x150 0x8000001100000000; wrmsr -a 0x150 0x8000021100000000; echo "0:0" > /etc/cpu-undervolt-state; systemctl stop cpu-undervolt.service 2>/dev/null; systemctl disable cpu-undervolt.service 2>/dev/null' 2>/dev/null
        echo -e "${GREEN}Undervolt removed. Service disabled.${NC}"
        echo -e "${DIM}Re-enable with: power -set <offset>${NC}\n"
        return
    fi

    if [[ "${1:-}" == "-set" ]]; then
        local core_mv="${2:-}"
        local cache_mv="${3:-$core_mv}"

        if [[ -z "$core_mv" ]]; then
            echo -e "\n${BOLD}Usage:${NC}"
            echo "  power -set <offset>              Same offset for core and cache"
            echo "  power -set <core> <cache>         Different offsets"
            echo ""
            echo -e "${DIM}Examples:${NC}"
            echo "  power -set -100                  -100mV on both"
            echo "  power -set -120 -100             -120mV core, -100mV cache"
            echo ""
            return 1
        fi

        if ! [[ "$core_mv" =~ ^-[0-9]+$ ]]; then
            echo -e "${RED}Core offset must be a negative integer (got '$core_mv')${NC}"
            return 1
        fi
        if ! [[ "$cache_mv" =~ ^-[0-9]+$ ]]; then
            echo -e "${RED}Cache offset must be a negative integer (got '$cache_mv')${NC}"
            return 1
        fi

        local core_hex cache_hex
        core_hex=$(_power_encode_msr 0 "$core_mv")
        cache_hex=$(_power_encode_msr 2 "$cache_mv")
        local reset_core=$(_power_encode_msr 0 0)
        local reset_cache=$(_power_encode_msr 2 0)

        echo -e "\n${BOLD}Applying undervolt: core ${core_mv}mV / cache ${cache_mv}mV${NC}"

        sudo bash -c "
            modprobe msr 2>/dev/null
            wrmsr -a 0x150 ${core_hex}
            wrmsr -a 0x150 ${cache_hex}
            echo '${core_mv}:${cache_mv}' > /etc/cpu-undervolt-state

            cat > /etc/systemd/system/cpu-undervolt.service << SVCEOF
[Unit]
Description=Apply CPU undervolt (core ${core_mv}mV / cache ${cache_mv}mV)
After=multi-user.target

[Service]
Type=oneshot
ExecStart=/bin/bash -c 'modprobe msr; wrmsr -a 0x150 ${core_hex}; wrmsr -a 0x150 ${cache_hex}; echo ${core_mv}:${cache_mv} > /etc/cpu-undervolt-state'
ExecStop=/bin/bash -c 'modprobe msr; wrmsr -a 0x150 ${reset_core}; wrmsr -a 0x150 ${reset_cache}; echo 0:0 > /etc/cpu-undervolt-state'
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
SVCEOF

            systemctl daemon-reload
            systemctl enable cpu-undervolt.service
            systemctl restart cpu-undervolt.service
        " 2>/dev/null

        echo -e "${GREEN}Undervolt applied. Service enabled for boot.${NC}"
        echo -e "${DIM}  Core:  ${core_mv}mV (${core_hex})${NC}"
        echo -e "${DIM}  Cache: ${cache_mv}mV (${cache_hex})${NC}\n"
        return
    fi

    if [[ "${1:-}" == "-h" || "${1:-}" == "--help" ]]; then
        echo -e "\n${BOLD}power${NC} — CPU undervolt manager + system stats"
        echo ""
        echo "  power                            Show system power stats"
        echo "  power -set <offset>              Apply offset to core + cache"
        echo "  power -set <core> <cache>        Apply different core/cache offsets"
        echo "  power -reset                     Remove undervolt, disable service"
        echo ""
        echo -e "${DIM}Examples:${NC}"
        echo "  power -set -100                  -100mV on both planes"
        echo "  power -set -120 -100             -120mV core, -100mV cache"
        echo "  power -reset                     Back to stock voltage"
        echo ""
        return
    fi

    # ---- Status display ----
    echo ""
    echo -e "${BOLD}══════════════════════════════════════${NC}"
    echo -e "${BOLD}  POWER STATUS${NC}"
    echo -e "${BOLD}══════════════════════════════════════${NC}"

    # -- Undervolt status --
    local uv_state svc_active svc_enabled uv_core uv_cache
    uv_state=$(cat /etc/cpu-undervolt-state 2>/dev/null || echo "unknown")
    svc_active=$(systemctl is-active cpu-undervolt.service 2>/dev/null || echo "inactive")
    svc_enabled=$(systemctl is-enabled cpu-undervolt.service 2>/dev/null || echo "not found")

    uv_core="${uv_state%%:*}"
    uv_cache="${uv_state##*:}"

    echo -e "\n${CYAN}  Undervolt${NC}"
    if [[ "$svc_active" == "active" && "$uv_state" != "0:0" && "$uv_state" != "unknown" ]]; then
        if [[ "$uv_core" == "$uv_cache" ]]; then
            echo -e "  Offset:  ${GREEN}${uv_core}mV${NC} (Core + Cache)"
        else
            echo -e "  Core:    ${GREEN}${uv_core}mV${NC}"
            echo -e "  Cache:   ${GREEN}${uv_cache}mV${NC}"
        fi
        echo -e "  Service: ${GREEN}active, enabled at boot${NC}"
    elif [[ "$svc_enabled" == "enabled" ]]; then
        echo -e "  Offset:  ${YELLOW}${uv_core}:${uv_cache}mV (enabled but not confirmed active)${NC}"
        echo -e "  Service: ${YELLOW}${svc_active}${NC}"
    else
        echo -e "  Offset:  ${YELLOW}none${NC}"
        echo -e "  Service: ${YELLOW}${svc_enabled}${NC}"
    fi

    # -- CPU info --
    echo -e "\n${CYAN}  CPU${NC}"

    local freqs avg_freq max_freq min_freq count=0 sum=0
    while IFS= read -r f; do
        local mhz=${f%%.*}
        sum=$(( sum + mhz ))
        count=$(( count + 1 ))
        if [[ -z "${max_freq:-}" ]] || (( mhz > max_freq )); then max_freq=$mhz; fi
        if [[ -z "${min_freq:-}" ]] || (( mhz < min_freq )); then min_freq=$mhz; fi
    done < <(grep "cpu MHz" /proc/cpuinfo | awk '{print $4}')

    if (( count > 0 )); then
        avg_freq=$(( sum / count ))
        echo -e "  Avg freq:  ${avg_freq} MHz"
        echo -e "  Range:     ${min_freq}–${max_freq} MHz"
    fi

    local cpu_temp
    cpu_temp=$(cat /sys/class/hwmon/hwmon6/temp1_input 2>/dev/null)
    if [[ -n "$cpu_temp" ]]; then
        echo -e "  Pkg temp:  $(( cpu_temp / 1000 ))°C"
    fi

    local gov
    gov=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor 2>/dev/null || echo "unknown")
    echo -e "  Governor:  ${gov}"

    # -- GPU (NVIDIA) --
    if command -v nvidia-smi &>/dev/null; then
        local gpu_name gpu_temp gpu_power gpu_clock gpu_util
        gpu_name=$(nvidia-smi --query-gpu=name --format=csv,noheader 2>/dev/null)
        gpu_temp=$(nvidia-smi --query-gpu=temperature.gpu --format=csv,noheader,nounits 2>/dev/null)
        gpu_power=$(nvidia-smi --query-gpu=power.draw --format=csv,noheader,nounits 2>/dev/null)
        gpu_clock=$(nvidia-smi --query-gpu=clocks.current.graphics --format=csv,noheader,nounits 2>/dev/null)
        gpu_util=$(nvidia-smi --query-gpu=utilization.gpu --format=csv,noheader,nounits 2>/dev/null)
        if [[ -n "$gpu_name" ]]; then
            echo -e "\n${CYAN}  GPU${NC}"
            echo -e "  Model:     ${gpu_name}"
            echo -e "  Temp:      ${gpu_temp}°C"
            echo -e "  Power:     ${gpu_power}W"
            echo -e "  Clock:     ${gpu_clock} MHz"
            echo -e "  Usage:     ${gpu_util}%"
        fi
    fi

    # -- iGPU --
    local igpu_freq
    igpu_freq=$(cat /sys/class/drm/card1/gt_cur_freq_mhz 2>/dev/null)
    if [[ -n "$igpu_freq" ]]; then
        echo -e "\n${CYAN}  iGPU${NC}"
        echo -e "  Freq:      ${igpu_freq} MHz"
    fi

    # -- Battery --
    local bat="/sys/class/power_supply/BAT0"
    if [[ -d "$bat" ]]; then
        local capacity status energy_now energy_full power_now health
        capacity=$(cat "$bat/capacity" 2>/dev/null || echo "N/A")
        status=$(cat "$bat/status" 2>/dev/null || echo "N/A")
        energy_now=$(cat "$bat/energy_now" 2>/dev/null)
        energy_full=$(cat "$bat/energy_full" 2>/dev/null)
        energy_full_design=$(cat "$bat/energy_full_design" 2>/dev/null)
        power_now=$(cat "$bat/power_now" 2>/dev/null)
        local cycles
        cycles=$(cat "$bat/cycle_count" 2>/dev/null || echo "N/A")

        echo -e "\n${CYAN}  Battery${NC}"
        echo -e "  Level:     ${capacity}%"
        echo -e "  Status:    ${status}"

        if [[ -n "$power_now" && "$power_now" != "0" ]]; then
            local watts
            watts=$(awk "BEGIN {printf \"%.1f\", $power_now / 1000000}")
            echo -e "  Draw:      ${watts}W"

            if [[ -n "$energy_now" && "$status" == "Discharging" ]]; then
                local hours_left
                hours_left=$(awk "BEGIN {printf \"%.1f\", $energy_now / $power_now}")
                echo -e "  Remaining: ~${hours_left}h"
            fi
        fi

        if [[ -n "$energy_full" && -n "$energy_full_design" ]]; then
            health=$(awk "BEGIN {printf \"%.1f\", ($energy_full / $energy_full_design) * 100}")
            echo -e "  Health:    ${health}%"
        fi

        echo -e "  Cycles:    ${cycles}"
    fi

    # -- AC power --
    local ac_online
    ac_online=$(cat /sys/class/power_supply/ADP0/online 2>/dev/null)
    echo -e "\n${CYAN}  Power Source${NC}"
    if [[ "$ac_online" == "1" ]]; then
        echo -e "  AC:        ${GREEN}plugged in${NC}"
    else
        echo -e "  AC:        ${YELLOW}on battery${NC}"
    fi

    # -- Memory --
    local mem_info
    mem_info=$(awk '/MemTotal/{t=$2} /MemAvailable/{a=$2} END{printf "%.1f / %.1f GB", (t-a)/1048576, t/1048576}' /proc/meminfo)
    echo -e "\n${CYAN}  Memory${NC}"
    echo -e "  Used:      ${mem_info}"

    echo -e "\n${BOLD}══════════════════════════════════════${NC}"
    echo -e "${DIM}  power -set <mV> | -reset | -h${NC}"
    echo ""
}
# --- end power ---
ENDFUNC

echo -e "  ${GREEN}Added 'power' command to $BASHRC${NC}"

# ---- 2. Remove unneeded packages --------------------------------------------
echo -e "\n${CYAN}[2/2] Cleaning up test dependencies...${NC}"

KEEP_PKGS=(msr-tools)
REMOVE_PKGS=(stress-ng s-tui)

to_remove=()
for pkg in "${REMOVE_PKGS[@]}"; do
    if dpkg -l "$pkg" 2>/dev/null | grep -q "^ii"; then
        to_remove+=("$pkg")
    fi
done

if (( ${#to_remove[@]} > 0 )); then
    echo "  Removing: ${to_remove[*]}"
    apt-get remove -y "${to_remove[@]}" > /dev/null 2>&1
    apt-get autoremove -y > /dev/null 2>&1
    echo -e "  ${GREEN}Removed: ${to_remove[*]}${NC}"
else
    echo -e "  ${GREEN}Nothing to remove${NC}"
fi

echo -e "  Keeping: ${KEEP_PKGS[*]} (needed for undervolt)"

# ---- Done --------------------------------------------------------------------
echo -e "\n${BOLD}${GREEN}=== Setup Complete ===${NC}\n"
echo "  Open a new terminal and use:"
echo ""
echo "    power -set -100             Apply -100mV to both planes"
echo "    power -set -120 -100        Apply -120mV core, -100mV cache"
echo "    power -reset                Remove undervolt"
echo "    power                       Show system stats"
echo ""