better statusbar

Firmware/AGENTS.md

@@ -0,0 +1,4 @@
+To build:
+(in zsh)
+. "$HOME/esp/esp-idf/export.sh"
+idf.py build

Firmware/components/backend-esp/include/cardboy/backend/esp/buzzer.hpp

@@ -6,7 +6,7 @@
 
 class Buzzer {
 public:
-    static Buzzer &get();
+    static Buzzer& get();
 
     void init(); // call once from app_main
 
@@ -17,8 +17,8 @@ public:
     void beepRotate();
     void beepMove();
     void beepLock();
-    void beepLines(int lines);      // 1..4 lines
+    void beepLines(int lines);   // 1..4 lines
-    void beepLevelUp(int level);    // after increment
+    void beepLevelUp(int level); // after increment
     void beepGameOver();
 
     // Mute controls
@@ -26,29 +26,29 @@ public:
     void toggleMuted();
     bool isMuted() const { return _muted; }
 
-    // Persistence
-    void loadState();
-    void saveState();
-
 private:
-    struct Step { uint32_t freq; uint32_t dur_ms; uint32_t gap_ms; };
+    struct Step {
+        uint32_t freq;
+        uint32_t dur_ms;
+        uint32_t gap_ms;
+    };
     static constexpr int MAX_QUEUE = 16;
-    Step _queue[MAX_QUEUE]{};
+    Step                 _queue[MAX_QUEUE]{};
-    int  _q_head = 0; // inclusive
+    int                  _q_head  = 0;       // inclusive
-    int  _q_tail = 0; // exclusive
+    int                  _q_tail  = 0;       // exclusive
-    bool _running = false;
+    bool                 _running = false;
-    bool _in_gap  = false;
+    bool                 _in_gap  = false;
-    void *_timer  = nullptr; // esp_timer_handle_t (opaque here)
+    void*                _timer   = nullptr; // esp_timer_handle_t (opaque here)
-    bool _muted   = false;
+    bool                 _muted   = false;
 
     Buzzer() = default;
-    void enqueue(const Step &s);
+    void        enqueue(const Step& s);
-    bool empty() const { return _q_head == _q_tail; }
+    bool        empty() const { return _q_head == _q_tail; }
-    Step &front() { return _queue[_q_head]; }
+    Step&       front() { return _queue[_q_head]; }
-    void popFront();
+    void        popFront();
-    void startNext();
+    void        startNext();
-    void schedule(uint32_t ms, bool gapPhase);
+    void        schedule(uint32_t ms, bool gapPhase);
-    void applyFreq(uint32_t freq);
+    void        applyFreq(uint32_t freq);
-    static void timerCb(void *arg);
+    static void timerCb(void* arg);
-    void clearQueue() { _q_head = _q_tail = 0; }
+    void        clearQueue() { _q_head = _q_tail = 0; }
 };

Firmware/components/backend-esp/src/buzzer.cpp

@@ -5,30 +5,18 @@
 #include <driver/ledc.h>
 #include <esp_err.h>
 #include <esp_timer.h>
-#include <nvs_flash.h>
-#include <nvs.h>
 
-static constexpr ledc_mode_t    LEDC_MODE   = LEDC_LOW_SPEED_MODE; // low speed is fine
+static constexpr ledc_mode_t      LEDC_MODE  = LEDC_LOW_SPEED_MODE; // low speed is fine
-static constexpr ledc_timer_t   LEDC_TIMER  = LEDC_TIMER_0;
+static constexpr ledc_timer_t     LEDC_TIMER = LEDC_TIMER_0;
-static constexpr ledc_channel_t LEDC_CH     = LEDC_CHANNEL_0;
+static constexpr ledc_channel_t   LEDC_CH    = LEDC_CHANNEL_0;
-static constexpr ledc_timer_bit_t LEDC_BITS = LEDC_TIMER_10_BIT;
+static constexpr ledc_timer_bit_t LEDC_BITS  = LEDC_TIMER_10_BIT;
 
-Buzzer &Buzzer::get() {
+Buzzer& Buzzer::get() {
     static Buzzer b;
     return b;
 }
 
 void Buzzer::init() {
-    // Initialize NVS once (safe if already done)
-    static bool nvsInited = false;
-    if (!nvsInited) {
-        esp_err_t err = nvs_flash_init();
-        if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
-            nvs_flash_erase();
-            nvs_flash_init();
-        }
-        nvsInited = true;
-    }
     ledc_timer_config_t tcfg{};
     tcfg.speed_mode      = LEDC_MODE;
     tcfg.timer_num       = LEDC_TIMER;
@@ -52,7 +40,6 @@ void Buzzer::init() {
     args.arg      = this;
     args.name     = "buzz";
     ESP_ERROR_CHECK(esp_timer_create(&args, reinterpret_cast<esp_timer_handle_t*>(&_timer)));
-    loadState();
 }
 
 void Buzzer::applyFreq(uint32_t freq) {
@@ -65,7 +52,7 @@ void Buzzer::applyFreq(uint32_t freq) {
     ledc_update_duty(LEDC_MODE, LEDC_CH);
 }
 
-void Buzzer::enqueue(const Step &s) {
+void Buzzer::enqueue(const Step& s) {
     int nextTail = (_q_tail + 1) % MAX_QUEUE;
     if (nextTail == _q_head) { // full, drop oldest
         _q_head = (_q_head + 1) % MAX_QUEUE;
@@ -87,21 +74,23 @@ void Buzzer::startNext() {
     }
     _running = true;
     _in_gap  = false;
-    Step &s  = front();
+    Step& s  = front();
     applyFreq(s.freq);
     schedule(s.dur_ms, false);
 }
 
 void Buzzer::schedule(uint32_t ms, bool gapPhase) {
-    if (!_timer) return;
+    if (!_timer)
+        return;
     _in_gap = gapPhase;
     esp_timer_stop(reinterpret_cast<esp_timer_handle_t>(_timer));
-    esp_timer_start_once(reinterpret_cast<esp_timer_handle_t>(_timer), (uint64_t)ms * 1000ULL);
+    esp_timer_start_once(reinterpret_cast<esp_timer_handle_t>(_timer), (uint64_t) ms * 1000ULL);
 }
 
-void Buzzer::timerCb(void *arg) {
+void Buzzer::timerCb(void* arg) {
-    auto *self = static_cast<Buzzer*>(arg);
+    auto* self = static_cast<Buzzer*>(arg);
-    if (!self) return;
+    if (!self)
+        return;
     if (self->_in_gap) {
         self->popFront();
         self->startNext();
@@ -109,7 +98,7 @@ void Buzzer::timerCb(void *arg) {
     }
     // Tone finished
     if (!self->empty()) {
-        auto &s = self->front();
+        auto& s = self->front();
         if (s.gap_ms) {
             self->applyFreq(0);
             self->schedule(s.gap_ms, true);
@@ -121,7 +110,8 @@ void Buzzer::timerCb(void *arg) {
 }
 
 void Buzzer::tone(uint32_t freq, uint32_t duration_ms, uint32_t gap_ms) {
-    if (_muted) return; // ignore while muted
+    if (_muted)
+        return; // ignore while muted
     Step s{freq, duration_ms, gap_ms};
     enqueue(s);
     if (!_running)
@@ -149,7 +139,8 @@ void Buzzer::beepGameOver() {
 }
 
 void Buzzer::setMuted(bool m) {
-    if (m == _muted) return;
+    if (m == _muted)
+        return;
     _muted = m;
     if (_muted) {
         clearQueue();
@@ -164,28 +155,6 @@ void Buzzer::setMuted(bool m) {
         tone(1500, 40, 10);
         tone(1900, 60, 0);
     }
-    saveState();
 }
 
 void Buzzer::toggleMuted() { setMuted(!_muted); }
-
-void Buzzer::loadState() {
-    nvs_handle_t h;
-    if (nvs_open("cfg", NVS_READONLY, &h) == ESP_OK) {
-        uint8_t v = 0;
-        if (nvs_get_u8(h, "mute", &v) == ESP_OK) {
-            _muted = (v != 0);
-        }
-        nvs_close(h);
-    }
-    if (_muted) applyFreq(0);
-}
-
-void Buzzer::saveState() {
-    nvs_handle_t h;
-    if (nvs_open("cfg", NVS_READWRITE, &h) == ESP_OK) {
-        nvs_set_u8(h, "mute", _muted ? 1 : 0);
-        nvs_commit(h);
-        nvs_close(h);
-    }
-}

Firmware/ghettoprof.sh

@@ -0,0 +1,248 @@
+#!/usr/bin/env bash
+# parallel-pc-profile.sh — parallel symbol resolver + optional annotated disassembly
+# Supports C++ demangling, LLVM disassembler, and optional no-inlines aggregation (symbol-table based).
+#
+# Usage:
+#   ./parallel-pc-profile.sh [-j jobs] [--annotate] [--no-inlines] firmware.elf pcs.txt
+
+set -euo pipefail
+
+usage() {
+  echo "Usage: $0 [-j jobs] [--annotate] [--no-inlines] firmware.elf pcs.txt"
+  exit 1
+}
+
+ANNOTATE=0
+JOBS=""
+NO_INLINES=0
+
+# ---- args ----
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    -j) JOBS="$2"; shift 2 ;;
+    --annotate) ANNOTATE=1; shift ;;
+    --no-inlines) NO_INLINES=1; shift ;;
+    -h|--help) usage ;;
+    *) break ;;
+  esac
+done
+[[ $# -lt 2 ]] && usage
+ELF="$1"
+PCS_IN="$2"
+
+[[ ! -f "$ELF" ]] && { echo "ELF not found: $ELF" >&2; exit 2; }
+[[ ! -f "$PCS_IN" ]] && { echo "PC log not found: $PCS_IN" >&2; exit 3; }
+
+# ---- tools ----
+ADDR2LINE=""
+for t in llvm-addr2line eu-addr2line riscv32-esp-elf-addr2line xtensa-esp32-elf-addr2line addr2line; do
+  if command -v "$t" >/dev/null 2>&1; then ADDR2LINE="$t"; break; fi
+done
+[[ -z "$ADDR2LINE" ]] && { echo "No addr2line found"; exit 4; }
+
+if command -v llvm-objdump >/dev/null 2>&1; then
+  OBJDUMP="llvm-objdump"
+else
+  for t in riscv32-esp-elf-objdump xtensa-esp32-elf-objdump objdump; do
+    if command -v "$t" >/dev/null 2>&1; then OBJDUMP="$t"; break; fi
+  done
+fi
+[[ -z "${OBJDUMP:-}" ]] && { echo "No objdump found"; exit 5; }
+
+if command -v llvm-nm >/dev/null 2>&1; then
+  NM="llvm-nm"
+elif command -v nm >/dev/null 2>&1; then
+  NM="nm"
+else
+  NM=""
+fi
+
+if command -v c++filt >/dev/null 2>&1; then
+  CPPFILT="c++filt"
+elif command -v llvm-cxxfilt >/dev/null 2>&1; then
+  CPPFILT="llvm-cxxfilt"
+else
+  CPPFILT=""
+fi
+
+# ---- cores ----
+if [[ -z "$JOBS" ]]; then
+  if command -v nproc >/dev/null 2>&1; then JOBS=$(nproc)
+  elif [[ "$OSTYPE" == "darwin"* ]]; then JOBS=$(sysctl -n hw.ncpu 2>/dev/null || echo 4)
+  else JOBS=$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 4)
+  fi
+fi
+(( JOBS = JOBS > 1 ? JOBS - 1 : 1 ))
+echo ">> Using $JOBS parallel jobs"
+
+TMP=$(mktemp -d)
+trap 'rm -rf "$TMP"' EXIT
+
+# ---- extract PCs ----
+grep -aoE '0x[0-9a-fA-F]+' "$PCS_IN" | tr 'A-F' 'a-f' | sort | uniq -c >"$TMP/pc_counts.txt" || true
+awk '{print $2}' "$TMP/pc_counts.txt" >"$TMP/addrs.txt"
+[[ ! -s "$TMP/addrs.txt" ]] && { echo "No addresses found"; exit 5; }
+
+# ---- parallel addr2line (live PC -> function to stderr) ----
+CHUNK=400
+split -l "$CHUNK" "$TMP/addrs.txt" "$TMP/chunk."
+
+find "$TMP" -name 'chunk.*' -type f -print0 \
+| xargs -0 -I{} -n1 -P "$JOBS" bash -c '
+  set -euo pipefail
+  ADDR2LINE="$1"; ELF="$2"; CHUNK="$3"; CPP="$4"
+  OUT="${CHUNK}.sym"
+  "$ADDR2LINE" -a -f -e "$ELF" $(cat "$CHUNK") \
+    | tee "$OUT" \
+    | awk '"'"'NR%3==1{a=$0;next} NR%3==2{f=$0; printf "%s\t%s\n",a,f; next} NR%3==0{next}'"'"' \
+    | { if [[ -n "$CPP" ]]; then "$CPP"; else cat; fi; } 1>&2
+' _ "$ADDR2LINE" "$ELF" {} "$CPPFILT"
+
+# Collate triplets
+cat "$TMP"/chunk.*.sym > "$TMP/symbols.raw"
+
+# ---- parse 3-line addr/func/file:line ----
+# Normalize leading zeros in addresses so joins match grep-extracted PCs
+awk 'NR%3==1{a=$0; sub(/^0x0+/, "0x", a); next} NR%3==2{f=$0; next} NR%3==0{print a "\t" f "\t" $0}' \
+  "$TMP/symbols.raw" >"$TMP/map.tsv"
+
+# ---- counts: addr -> samplecount ----
+awk '{printf "%s\t%s\n",$2,$1}' "$TMP/pc_counts.txt" | sort -k1,1 >"$TMP/counts.tsv"
+
+# ---- choose mapping: default (addr2line; may show inlined names) vs --no-inlines (symbol-table) ----
+DEFAULT_ADDR_FUNC="$TMP/addr_func.tsv"
+cut -f1,2 "$TMP/map.tsv" | sort -k1,1 >"$DEFAULT_ADDR_FUNC"
+
+if [[ "$NO_INLINES" == "1" ]]; then
+  if [[ -z "$NM" ]]; then
+    echo "WARNING: nm/llvm-nm not found; falling back to inline-aware mapping." >&2
+    ADDR_FUNC_FILE="$DEFAULT_ADDR_FUNC"
+  else
+    echo ">> Building symbol table for no-inlines mapping..."
+    # Create sorted function symbols: hexaddr\tname (demangled if possible afterwards)
+    # Try llvm-nm format first; fall back to generic nm.
+    if [[ "$NM" == "llvm-nm" ]]; then
+      # llvm-nm -n --defined-only emits: ADDRESS TYPE NAME
+      "$NM" -n --defined-only "$ELF" \
+        | awk '/ [Tt] /{print $1 "\t" $3}' > "$TMP/syms.raw"
+    else
+      # generic nm -n emits: ADDRESS TYPE NAME (varies a bit across platforms)
+      "$NM" -n --defined-only "$ELF" 2>/dev/null \
+        | awk '/ [Tt] /{print $1 "\t" $3}' > "$TMP/syms.raw" || true
+      # macOS nm might output different columns; handle common alt layout:
+      if [[ ! -s "$TMP/syms.raw" ]]; then
+        "$NM" -n "$ELF" 2>/dev/null | awk '/ [Tt] /{print $1 "\t" $3}' > "$TMP/syms.raw" || true
+      fi
+    fi
+
+    if [[ -n "$CPPFILT" && -s "$TMP/syms.raw" ]]; then
+      "$CPPFILT" < "$TMP/syms.raw" > "$TMP/syms.dem.raw" || cp "$TMP/syms.raw" "$TMP/syms.dem.raw"
+    else
+      cp "$TMP/syms.raw" "$TMP/syms.dem.raw"
+    fi
+
+    # Normalize addresses and sort ascending
+    awk '{addr=$1; sub(/^0x0+/, "0x", addr); print addr "\t" $2}' "$TMP/syms.dem.raw" \
+      | awk 'NF' \
+      | sort -k1,1 > "$TMP/syms.tsv"
+
+    if [[ ! -s "$TMP/syms.tsv" ]]; then
+      echo "WARNING: no text symbols found; falling back to inline-aware mapping." >&2
+      ADDR_FUNC_FILE="$DEFAULT_ADDR_FUNC"
+    else
+      # Map each PC to the *containing* function: last symbol with addr <= PC.
+      # Both syms.tsv and addrs.txt are sorted asc → single pass merge.
+      awk '
+        function hex2num(h,  x, n,i,c) {
+          gsub(/^0x/,"",h); n=0
+          for(i=1;i<=length(h);i++){ c=substr(h,i,1)
+            x = index("0123456789abcdef", tolower(c)) - 1
+            if (x<0) x = index("0123456789ABCDEF", c) - 1
+            n = n*16 + x
+          }
+          return n
+        }
+        BEGIN {
+          # preload symbols
+          while ((getline < ARGV[1]) > 0) {
+            saddr[NSYM]=$1; sname[NSYM]=$2; NSYM++
+          }
+          # load PCs
+          while ((getline < ARGV[2]) > 0) {
+            pc[NPC]=$0; NPC++
+          }
+          # pointers
+          si=0
+          for (i=0; i<NPC; i++) {
+            p=pc[i]; pn=hex2num(p)
+            # advance symbol index while next symbol start <= pc
+            while (si+1<NSYM && hex2num(saddr[si+1]) <= pn) si++
+            # output mapping: p -> sname[si] (if any)
+            if (si<NSYM && hex2num(saddr[si]) <= pn)
+              printf "%s\t%s\n", p, sname[si]
+            else
+              printf "%s\t<unknown>\n", p
+          }
+          exit 0
+        }
+      ' "$TMP/syms.tsv" "$TMP/addrs.txt" \
+      | sort -k1,1 > "$TMP/addr_func.noinline.tsv"
+
+      ADDR_FUNC_FILE="$TMP/addr_func.noinline.tsv"
+    fi
+  fi
+else
+  ADDR_FUNC_FILE="$DEFAULT_ADDR_FUNC"
+fi
+
+# ---- aggregate to hot functions ----
+join -t $'\t' -a1 -e "<unknown>" -o 1.2,2.2 "$TMP/counts.tsv" "$ADDR_FUNC_FILE" \
+| awk -F'\t' '{s[$2]+=$1} END{for(k in s) printf "%8d  %s\n",s[k],k}' \
+| sort -nr > "$TMP/hot.txt"
+
+# ---- demangle final hot list (if available) ----
+if [[ -n "$CPPFILT" ]]; then
+  "$CPPFILT" < "$TMP/hot.txt" > hot_functions.txt
+else
+  cp "$TMP/hot.txt" hot_functions.txt
+fi
+
+echo "=== Top 50 hot functions ==="
+head -50 hot_functions.txt
+echo "Full list in: hot_functions.txt"
+
+# ---- annotated source+assembly (optional) ----
+if (( ANNOTATE )); then
+  echo ">> Generating annotated source+assembly..."
+  awk '{printf "%s %s\n",$2,$1}' "$TMP/pc_counts.txt" >"$TMP/count.map"
+
+  if [[ "$OBJDUMP" == "llvm-objdump" ]]; then
+    # Portable across llvm-objdump versions
+    "$OBJDUMP" --source -l --demangle -d "$ELF" >"$TMP/disasm.txt"
+  else
+    "$OBJDUMP" -S -C -l -d "$ELF" >"$TMP/disasm.txt"
+  fi
+
+  # Overlay hit counts onto the disassembly
+  awk -v counts="$TMP/count.map" '
+    BEGIN {
+      while ((getline < counts) > 0) {
+        addr=$1; cnt=$2
+        gsub(/^0x/,"",addr)
+        map[addr]=cnt
+      }
+    }
+    /^[[:space:]]*[0-9a-f]+:/ {
+      split($1,a,":"); key=a[1]
+      if (key in map)
+        printf("%-12s %6d | %s\n", $1, map[key], substr($0, index($0,$2)))
+      else
+        print $0
+      next
+    }
+    { print }
+  ' "$TMP/disasm.txt" > annotated.S
+
+  echo "Annotated source + assembly written to: annotated.S"
+  echo "Tip: less -R annotated.S"
+fi

Firmware/main/src/app_main.cpp

@@ -1,17 +1,20 @@
 // Cardboy firmware entry point: boot platform services and run the modular app system.
 
-#include "cardboy/backend/esp_backend.hpp"
 #include "cardboy/apps/clock_app.hpp"
 #include "cardboy/apps/gameboy_app.hpp"
 #include "cardboy/apps/menu_app.hpp"
+#include "cardboy/apps/settings_app.hpp"
 #include "cardboy/apps/tetris_app.hpp"
+#include "cardboy/backend/esp_backend.hpp"
 #include "cardboy/sdk/app_system.hpp"
+#include "cardboy/sdk/persistent_settings.hpp"
 
-#include "freertos/FreeRTOS.h"
-#include "freertos/task.h"
 #include "esp_err.h"
 #include "esp_pm.h"
 #include "esp_sleep.h"
+#include "esp_system.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
 #include "sdkconfig.h"
 
 #include <algorithm>
@@ -19,9 +22,9 @@
 #include <cstdint>
 #include <cstdio>
 #include <cstring>
+#include <span>
 #include <string>
 #include <string_view>
-#include <span>
 #include <vector>
 
 namespace {
@@ -53,11 +56,11 @@ constexpr apps::EmbeddedRomDescriptor kEmbeddedRoms[] = {
 #if CONFIG_FREERTOS_GENERATE_RUN_TIME_STATS && CONFIG_FREERTOS_USE_TRACE_FACILITY
 namespace {
 
-constexpr TickType_t kStatsTaskDelayTicks = pdMS_TO_TICKS(5000);
+constexpr TickType_t  kStatsTaskDelayTicks = pdMS_TO_TICKS(5000);
-constexpr TickType_t kStatsWarmupDelay    = pdMS_TO_TICKS(2000);
+constexpr TickType_t  kStatsWarmupDelay    = pdMS_TO_TICKS(2000);
-constexpr UBaseType_t kStatsTaskPriority  = tskIDLE_PRIORITY + 1;
+constexpr UBaseType_t kStatsTaskPriority   = tskIDLE_PRIORITY + 1;
-constexpr uint32_t    kStatsTaskStack     = 4096;
+constexpr uint32_t    kStatsTaskStack      = 4096;
-constexpr char        kStatsTaskName[]    = "TaskStats";
+constexpr char        kStatsTaskName[]     = "TaskStats";
 
 struct TaskRuntimeSample {
     TaskHandle_t handle;
@@ -65,11 +68,11 @@ struct TaskRuntimeSample {
 };
 
 struct TaskUsageRow {
-    std::string  name;
+    std::string name;
-    uint64_t     delta;
+    uint64_t    delta;
-    UBaseType_t  priority;
+    UBaseType_t priority;
-    uint32_t     stackHighWaterBytes;
+    uint32_t    stackHighWaterBytes;
-    bool         isIdle;
+    bool        isIdle;
 };
 
 [[nodiscard]] uint64_t deltaWithWrap(uint32_t current, uint32_t previous) {
@@ -79,7 +82,7 @@ struct TaskUsageRow {
 }
 
 void task_usage_monitor(void*) {
-    static constexpr char tag[] = "TaskUsage";
+    static constexpr char          tag[] = "TaskUsage";
     std::vector<TaskRuntimeSample> lastSamples;
     uint32_t                       lastTotal = 0;
 
@@ -94,7 +97,7 @@ void task_usage_monitor(void*) {
 
         std::vector<TaskStatus_t> statusBuffer(taskCount);
         uint32_t                  totalRuntime = 0;
-        const UBaseType_t         captured     = uxTaskGetSystemState(statusBuffer.data(), statusBuffer.size(), &totalRuntime);
+        const UBaseType_t captured = uxTaskGetSystemState(statusBuffer.data(), statusBuffer.size(), &totalRuntime);
         if (captured == 0)
             continue;
         statusBuffer.resize(captured);
@@ -118,8 +121,8 @@ void task_usage_monitor(void*) {
         std::vector<TaskUsageRow> rows;
         rows.reserve(statusBuffer.size());
 
-        uint64_t idleDelta    = 0;
+        uint64_t idleDelta      = 0;
-        uint64_t activeDelta  = 0;
+        uint64_t activeDelta    = 0;
         uint64_t accountedDelta = 0;
 
         for (const auto& status: statusBuffer) {
@@ -128,18 +131,18 @@ void task_usage_monitor(void*) {
             });
 
             const uint32_t previousRuntime = (it != lastSamples.end()) ? it->runtime : status.ulRunTimeCounter;
-            const uint64_t taskDelta       = (it != lastSamples.end()) ? deltaWithWrap(status.ulRunTimeCounter, previousRuntime) : 0ULL;
+            const uint64_t taskDelta =
+                    (it != lastSamples.end()) ? deltaWithWrap(status.ulRunTimeCounter, previousRuntime) : 0ULL;
 
             currentSamples.push_back({status.xHandle, status.ulRunTimeCounter});
 
-            TaskUsageRow row{
+            TaskUsageRow row{.name     = std::string(status.pcTaskName ? status.pcTaskName : ""),
-                    .name                 = std::string(status.pcTaskName ? status.pcTaskName : ""),
+                             .delta    = taskDelta,
-                    .delta                = taskDelta,
+                             .priority = status.uxCurrentPriority,
-                    .priority             = status.uxCurrentPriority,
+                             .stackHighWaterBytes =
-                    .stackHighWaterBytes  = static_cast<uint32_t>(status.usStackHighWaterMark) * sizeof(StackType_t),
+                                     static_cast<uint32_t>(status.usStackHighWaterMark) * sizeof(StackType_t),
-                    .isIdle               = status.uxCurrentPriority == tskIDLE_PRIORITY ||
+                             .isIdle = status.uxCurrentPriority == tskIDLE_PRIORITY ||
-                                            (status.pcTaskName && std::strncmp(status.pcTaskName, "IDLE", 4) == 0)
+                                       (status.pcTaskName && std::strncmp(status.pcTaskName, "IDLE", 4) == 0)};
-            };
 
             rows.push_back(std::move(row));
 
@@ -156,9 +159,8 @@ void task_usage_monitor(void*) {
         if (rows.empty())
             continue;
 
-        std::sort(rows.begin(), rows.end(), [](const TaskUsageRow& a, const TaskUsageRow& b) {
+        std::sort(rows.begin(), rows.end(),
-            return a.delta > b.delta;
+                  [](const TaskUsageRow& a, const TaskUsageRow& b) { return a.delta > b.delta; });
-        });
 
         const double windowMs = static_cast<double>(totalDelta) / 1000.0;
 
@@ -181,14 +183,20 @@ void task_usage_monitor(void*) {
             std::printf("  %-16s %6.2f%%  (ISRs / scheduler)\n", "<isr>", residualPct);
         }
 
-        std::printf("[%s] Active %.2f%% | Idle %.2f%%\n", tag,
+        std::printf("[%s] Active %.2f%% | Idle %.2f%%\n", tag, (activeDelta * 100.0) / static_cast<double>(totalDelta),
-                    (activeDelta * 100.0) / static_cast<double>(totalDelta), idlePct);
+                    idlePct);
+
+        const uint32_t heapFree    = esp_get_free_heap_size();
+        const uint32_t heapMinimum = esp_get_minimum_free_heap_size();
+        std::printf("[%s] Heap free %lu B | Min free %lu B\n", tag, static_cast<unsigned long>(heapFree),
+                    static_cast<unsigned long>(heapMinimum));
         std::fflush(stdout);
     }
 }
 
 void start_task_usage_monitor() {
-    xTaskCreatePinnedToCore(task_usage_monitor, kStatsTaskName, kStatsTaskStack, nullptr, kStatsTaskPriority, nullptr, 0);
+    xTaskCreatePinnedToCore(task_usage_monitor, kStatsTaskName, kStatsTaskStack, nullptr, kStatsTaskPriority, nullptr,
+                            0);
 }
 
 } // namespace
@@ -197,15 +205,6 @@ inline void start_task_usage_monitor() {}
 #endif
 
 extern "C" void app_main() {
-#ifdef CONFIG_PM_ENABLE
-    // const esp_pm_config_t pm_config = {
-    //         .max_freq_mhz       = CONFIG_ESP_DEFAULT_CPU_FREQ_MHZ,
-    //         .min_freq_mhz       = 16,
-    //         .light_sleep_enable = true};
-    // ESP_ERROR_CHECK(esp_pm_configure(&pm_config));
-    ESP_ERROR_CHECK(esp_sleep_enable_gpio_wakeup());
-#endif
-
     apps::setGameboyEmbeddedRoms(std::span<const apps::EmbeddedRomDescriptor>(kEmbeddedRoms));
 
     static cardboy::backend::esp::EspRuntime runtime;
@@ -215,12 +214,30 @@ extern "C" void app_main() {
     cardboy::sdk::AppSystem system(context);
     context.system = &system;
 
+    const cardboy::sdk::PersistentSettings persistentSettings =
+            cardboy::sdk::loadPersistentSettings(context.getServices());
+    if (auto* buzzer = context.buzzer())
+        buzzer->setMuted(persistentSettings.mute);
+
+#ifdef CONFIG_PM_ENABLE
+    if (persistentSettings.autoLightSleep) {
+        const esp_pm_config_t pm_config = {
+                .max_freq_mhz       = CONFIG_ESP_DEFAULT_CPU_FREQ_MHZ,
+                .min_freq_mhz       = 16,
+                .light_sleep_enable = true,
+        };
+        ESP_ERROR_CHECK(esp_pm_configure(&pm_config));
+    }
+    ESP_ERROR_CHECK(esp_sleep_enable_gpio_wakeup());
+#endif
+
     system.registerApp(apps::createMenuAppFactory());
+    system.registerApp(apps::createSettingsAppFactory());
     system.registerApp(apps::createClockAppFactory());
     system.registerApp(apps::createTetrisAppFactory());
     system.registerApp(apps::createGameboyAppFactory());
 
-    start_task_usage_monitor();
+    // start_task_usage_monitor();
 
     system.run();
 }

Firmware/sdk/apps/CMakeLists.txt

@@ -14,5 +14,6 @@ target_compile_features(cardboy_apps PUBLIC cxx_std_20)
 
 add_subdirectory(menu)
 add_subdirectory(clock)
+add_subdirectory(settings)
 add_subdirectory(gameboy)
 add_subdirectory(tetris)

Firmware/sdk/apps/settings/CMakeLists.txt

@@ -0,0 +1,9 @@
+target_sources(cardboy_apps
+        PRIVATE
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/settings_app.cpp
+)
+
+target_include_directories(cardboy_apps
+        PUBLIC
+        ${CMAKE_CURRENT_SOURCE_DIR}/include
+)

Firmware/sdk/apps/settings/include/cardboy/apps/settings_app.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "cardboy/sdk/app_framework.hpp"
+
+#include <memory>
+
+namespace apps {
+
+inline constexpr char kSettingsAppName[] = "Settings";
+
+std::unique_ptr<cardboy::sdk::IAppFactory> createSettingsAppFactory();
+
+} // namespace apps

Firmware/sdk/apps/settings/src/settings_app.cpp

@@ -0,0 +1,198 @@
+#include "cardboy/apps/settings_app.hpp"
+
+#include "cardboy/apps/menu_app.hpp"
+#include "cardboy/gfx/font16x8.hpp"
+#include "cardboy/sdk/app_framework.hpp"
+#include "cardboy/sdk/persistent_settings.hpp"
+
+#include <array>
+#include <cstddef>
+#include <memory>
+#include <string>
+#include <string_view>
+
+namespace apps {
+
+namespace {
+
+using cardboy::sdk::AppContext;
+using Framebuffer = typename AppContext::Framebuffer;
+
+enum class SettingOption {
+    Sound,
+    AutoLightSleep,
+};
+
+constexpr std::array<SettingOption, 2> kOptions = {
+        SettingOption::Sound,
+        SettingOption::AutoLightSleep,
+};
+
+class SettingsApp final : public cardboy::sdk::IApp {
+public:
+    explicit SettingsApp(AppContext& ctx) : context(ctx), framebuffer(ctx.framebuffer) {}
+
+    void onStart() override {
+        loadSettings();
+        dirty = true;
+        renderIfNeeded();
+    }
+
+    void handleEvent(const cardboy::sdk::AppEvent& event) override {
+        if (event.type != cardboy::sdk::AppEventType::Button)
+            return;
+
+        const auto& current  = event.button.current;
+        const auto& previous = event.button.previous;
+
+        const bool previousAvailable = buzzerAvailable;
+        syncBuzzerState();
+        if (previousAvailable != buzzerAvailable)
+            dirty = true;
+
+        if (current.b && !previous.b) {
+            context.requestAppSwitchByName(kMenuAppName);
+            return;
+        }
+
+        bool moved = false;
+        if (current.down && !previous.down) {
+            moveSelection(+1);
+            moved = true;
+        } else if (current.up && !previous.up) {
+            moveSelection(-1);
+            moved = true;
+        }
+
+        const bool togglePressed = (current.a && !previous.a) || (current.select && !previous.select) ||
+                                   (current.start && !previous.start);
+        if (togglePressed)
+            handleToggle();
+
+        if (moved)
+            dirty = true;
+
+        renderIfNeeded();
+    }
+
+private:
+    AppContext&  context;
+    Framebuffer& framebuffer;
+
+    bool                             buzzerAvailable = false;
+    cardboy::sdk::PersistentSettings settings{};
+    std::size_t                      selectedIndex = 0;
+    bool                             dirty         = false;
+
+    void loadSettings() {
+        settings = cardboy::sdk::loadPersistentSettings(context.getServices());
+        syncBuzzerState();
+    }
+
+    void syncBuzzerState() {
+        auto* buzzer    = context.buzzer();
+        buzzerAvailable = (buzzer != nullptr);
+        if (!buzzer)
+            return;
+        if (buzzer->isMuted() != settings.mute)
+            buzzer->setMuted(settings.mute);
+    }
+
+    void moveSelection(int delta) {
+        const int count = static_cast<int>(kOptions.size());
+        if (count == 0)
+            return;
+        const int current = static_cast<int>(selectedIndex);
+        int       next    = (current + delta) % count;
+        if (next < 0)
+            next += count;
+        selectedIndex = static_cast<std::size_t>(next);
+    }
+
+    void handleToggle() {
+        switch (kOptions[selectedIndex]) {
+            case SettingOption::Sound:
+                toggleSound();
+                break;
+            case SettingOption::AutoLightSleep:
+                toggleAutoLightSleep();
+                break;
+        }
+    }
+
+    void toggleSound() {
+        if (!buzzerAvailable)
+            return;
+        settings.mute = !settings.mute;
+        cardboy::sdk::savePersistentSettings(context.getServices(), settings);
+        syncBuzzerState();
+        if (!settings.mute) {
+            if (auto* buzzer = context.buzzer())
+                buzzer->beepMove();
+        }
+        dirty = true;
+    }
+
+    void toggleAutoLightSleep() {
+        settings.autoLightSleep = !settings.autoLightSleep;
+        cardboy::sdk::savePersistentSettings(context.getServices(), settings);
+        dirty = true;
+    }
+
+    static void drawCenteredText(Framebuffer& fb, int y, std::string_view text, int scale, int letterSpacing = 1) {
+        const int width = font16x8::measureText(text, scale, letterSpacing);
+        const int x     = (fb.width() - width) / 2;
+        font16x8::drawText(fb, x, y, text, scale, true, letterSpacing);
+    }
+
+    void drawOptionRow(int row, std::string_view label, std::string_view value, bool selected) {
+        std::string prefix = selected ? "> " : "  ";
+        std::string line   = prefix;
+        line.append(label);
+        line.append(": ");
+        line.append(value);
+        const int x = 24;
+        const int y = 56 + row * 24;
+        font16x8::drawText(framebuffer, x, y, line, 1, true, 1);
+    }
+
+    void renderIfNeeded() {
+        if (!dirty)
+            return;
+        dirty = false;
+
+        framebuffer.frameReady();
+        framebuffer.clear(false);
+
+        drawCenteredText(framebuffer, 24, "SETTINGS", 1, 1);
+
+        const std::string soundValue = buzzerAvailable ? (settings.mute ? "OFF" : "ON") : "N/A";
+        drawOptionRow(0, "SOUND", soundValue, selectedIndex == 0);
+
+        const std::string lightSleepValue = settings.autoLightSleep ? "ON" : "OFF";
+        drawOptionRow(1, "AUTO LIGHT SLEEP", lightSleepValue, selectedIndex == 1);
+
+        if (!buzzerAvailable)
+            drawCenteredText(framebuffer, 120, "SOUND CONTROL UNAVAILABLE", 1, 1);
+
+        drawCenteredText(framebuffer, framebuffer.height() - 54, "UP/DOWN MOVE", 1, 1);
+        drawCenteredText(framebuffer, framebuffer.height() - 36, "A/START/SELECT TOGGLE", 1, 1);
+        drawCenteredText(framebuffer, framebuffer.height() - 18, "B BACK | LIGHT SLEEP AFTER RESET", 1, 1);
+
+        framebuffer.sendFrame();
+    }
+};
+
+class SettingsAppFactory final : public cardboy::sdk::IAppFactory {
+public:
+    const char*                         name() const override { return kSettingsAppName; }
+    std::unique_ptr<cardboy::sdk::IApp> create(cardboy::sdk::AppContext& context) override {
+        return std::make_unique<SettingsApp>(context);
+    }
+};
+
+} // namespace
+
+std::unique_ptr<cardboy::sdk::IAppFactory> createSettingsAppFactory() { return std::make_unique<SettingsAppFactory>(); }
+
+} // namespace apps

Firmware/sdk/apps/tetris/src/tetris_app.cpp

@@ -70,13 +70,13 @@ constexpr Tetromino makeTetromino(std::initializer_list<BlockOffset> baseBlocks)
 }
 
 constexpr std::array<Tetromino, 7> kPieces = {{
-        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {2, 0}}),     // I
+        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {2, 0}}),  // I
-        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {1, 1}}),     // J
+        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {1, 1}}),  // J
-        makeTetromino({{-1, 1}, {-1, 0}, {0, 0}, {1, 0}}),    // L
+        makeTetromino({{-1, 1}, {-1, 0}, {0, 0}, {1, 0}}), // L
-        makeTetromino({{0, 0}, {1, 0}, {0, 1}, {1, 1}}),      // O
+        makeTetromino({{0, 0}, {1, 0}, {0, 1}, {1, 1}}),   // O
-        makeTetromino({{-1, 0}, {0, 0}, {0, 1}, {1, 1}}),     // S
+        makeTetromino({{-1, 0}, {0, 0}, {0, 1}, {1, 1}}),  // S
-        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {0, 1}}),     // T
+        makeTetromino({{-1, 0}, {0, 0}, {1, 0}, {0, 1}}),  // T
-        makeTetromino({{-1, 1}, {0, 1}, {0, 0}, {1, 0}}),     // Z
+        makeTetromino({{-1, 1}, {0, 1}, {0, 0}, {1, 0}}),  // Z
 }};
 
 class RandomBag {
@@ -107,22 +107,22 @@ private:
 };
 
 struct ActivePiece {
-    int type      = 0;
+    int type     = 0;
-    int rotation  = 0;
+    int rotation = 0;
-    int x         = 0;
+    int x        = 0;
-    int y         = 0;
+    int y        = 0;
 };
 
 struct GameState {
     std::array<int, kBoardWidth * kBoardHeight> board{};
-    ActivePiece current{};
+    ActivePiece                                 current{};
-    int         nextPiece    = 0;
+    int                                         nextPiece    = 0;
-    int         level        = 1;
+    int                                         level        = 1;
-    int         linesCleared = 0;
+    int                                         linesCleared = 0;
-    int         score        = 0;
+    int                                         score        = 0;
-    int         highScore    = 0;
+    int                                         highScore    = 0;
-    bool        paused       = false;
+    bool                                        paused       = false;
-    bool        gameOver     = false;
+    bool                                        gameOver     = false;
 };
 
 [[nodiscard]] std::uint32_t randomSeed(AppContext& ctx) {
@@ -161,21 +161,21 @@ public:
     }
 
 private:
-    AppContext&                     context;
+    AppContext&                       context;
     typename AppContext::Framebuffer& framebuffer;
 
-    GameState   state;
+    GameState      state;
-    RandomBag   bag;
+    RandomBag      bag;
-    InputState  lastInput{};
+    InputState     lastInput{};
-    bool        dirty      = false;
+    bool           dirty     = false;
-    AppTimerHandle dropTimer   = cardboy::sdk::kInvalidAppTimer;
+    AppTimerHandle dropTimer = cardboy::sdk::kInvalidAppTimer;
-    AppTimerHandle softTimer   = cardboy::sdk::kInvalidAppTimer;
+    AppTimerHandle softTimer = cardboy::sdk::kInvalidAppTimer;
 
     void reset() {
         cancelTimers();
-        int oldHigh = state.highScore;
+        int oldHigh        = state.highScore;
-        state       = {};
+        state              = {};
-        state.highScore = oldHigh;
+        state.highScore    = oldHigh;
         state.current.type = bag.next();
         state.nextPiece    = bag.next();
         state.current.x    = kBoardWidth / 2;
@@ -190,7 +190,7 @@ private:
     }
 
     void handleButtons(const AppButtonEvent& evt) {
-        const auto& cur = evt.current;
+        const auto& cur  = evt.current;
         const auto& prev = evt.previous;
         lastInput        = cur;
 
@@ -260,7 +260,7 @@ private:
     void scheduleDropTimer() {
         cancelDropTimer();
         const std::uint32_t interval = dropIntervalMs();
-        dropTimer = context.scheduleRepeatingTimer(interval);
+        dropTimer                    = context.scheduleRepeatingTimer(interval);
     }
 
     void cancelDropTimer() {
@@ -276,8 +276,8 @@ private:
     }
 
     [[nodiscard]] std::uint32_t dropIntervalMs() const {
-        const int base = 700;
+        const int base     = 700;
-        const int step = 50;
+        const int step     = 50;
         int       interval = base - (state.level - 1) * step;
         if (interval < 120)
             interval = 120;
@@ -322,7 +322,7 @@ private:
 
     void rotate(int direction) {
         int nextRot = state.current.rotation + (direction >= 0 ? 1 : -1);
-        nextRot      = ((nextRot % 4) + 4) % 4;
+        nextRot     = ((nextRot % 4) + 4) % 4;
         if (canPlace(state.current.x, state.current.y, nextRot)) {
             state.current.rotation = nextRot;
             dirty                  = true;
@@ -484,11 +484,10 @@ private:
         for (int y = 0; y < kBoardHeight; ++y) {
             for (int x = 0; x < kBoardWidth; ++x) {
                 if (int value = cellAt(x, y); value != 0)
-                    drawCell(originX, originY, x, y, value, true);
+                    drawCell(originX, originY, x, y, value - 1, true);
             }
         }
-
+        drawBoardFrame(originX, originY);
-        drawGuides(originX, originY);
     }
 
     void drawActivePiece() {
@@ -502,32 +501,76 @@ private:
             int gy = state.current.y + block.y;
             if (gy < 0)
                 continue;
-            drawCell(originX, originY, gx, gy, state.current.type + 1, false);
+            drawCell(originX, originY, gx, gy, state.current.type, false);
         }
     }
 
-    void drawCell(int originX, int originY, int cx, int cy, int value, bool solid) {
+    static bool patternPixel(int pieceIndex, int dx, int dy) {
-        const int x0 = originX + cx * kCellSize;
+        const int idx = std::clamp(pieceIndex, 0, static_cast<int>(kPieces.size()) - 1);
-        const int y0 = originY + cy * kCellSize;
+        const int mx  = dx & 0x3;
-        for (int dy = 0; dy < kCellSize; ++dy) {
+        const int my  = dy & 0x3;
-            for (int dx = 0; dx < kCellSize; ++dx) {
+        switch (idx) {
-                bool on = solid ? true : (dx == 0 || dx == kCellSize - 1 || dy == 0 || dy == kCellSize - 1);
+            case 0:   // I - vertical stripes
+                return mx < 2;
+            case 1:   // J - horizontal stripes
+                return my < 2;
+            case 2: { // L - forward diagonal
+                const int sum = (mx + my) & 0x3;
+                return sum < 2;
+            }
+            case 3:   // O - diamond centerpiece
+                return (mx == 1 && my == 1) || (mx == 2 && my == 1) || (mx == 1 && my == 2) || (mx == 2 && my == 2);
+            case 4:   // S - checkerboard
+                return ((mx ^ my) & 0x1) == 0;
+            case 5: { // T - cross
+                return (mx == 0) || (my == 0);
+            }
+            case 6: { // Z - backward diagonal
+                int diff = mx - my;
+                if (diff < 0)
+                    diff += 4;
+                diff &= 0x3;
+                return diff < 2;
+            }
+        }
+        return true;
+    }
+
+    void drawPatternBlock(int x0, int y0, int size, int pieceIndex, bool locked) {
+        const int idx = std::clamp(pieceIndex, 0, static_cast<int>(kPieces.size()) - 1);
+        for (int dy = 0; dy < size; ++dy) {
+            for (int dx = 0; dx < size; ++dx) {
+                const bool border = dx == 0 || dx == size - 1 || dy == 0 || dy == size - 1;
+                bool       fill   = patternPixel(idx, dx, dy);
+                if (!locked && !border)
+                    fill = fill && (((dx + dy) & 0x1) == 0);
+                const bool on = border || fill;
                 framebuffer.drawPixel(x0 + dx, y0 + dy, on);
             }
         }
-        (void) value; // value currently unused (monochrome display)
     }
 
-    void drawGuides(int originX, int originY) {
+    void drawCell(int originX, int originY, int cx, int cy, int pieceIndex, bool locked) {
-        for (int y = 0; y <= kBoardHeight; ++y) {
+        const int x0 = originX + cx * kCellSize;
-            const int py = originY + y * kCellSize;
+        const int y0 = originY + cy * kCellSize;
-            for (int x = 0; x < kBoardWidth * kCellSize; ++x)
+        drawPatternBlock(x0, y0, kCellSize, pieceIndex, locked);
-                framebuffer.drawPixel(originX + x, py, (y % 5) == 0);
+    }
+
+    void drawBoardFrame(int originX, int originY) {
+        const int widthPixels  = kBoardWidth * kCellSize;
+        const int heightPixels = kBoardHeight * kCellSize;
+        const int x0           = originX;
+        const int y0           = originY;
+        const int x1           = originX + widthPixels - 1;
+        const int y1           = originY + heightPixels - 1;
+
+        for (int x = x0; x <= x1; ++x) {
+            framebuffer.drawPixel(x, y0, true);
+            framebuffer.drawPixel(x, y1, true);
         }
-        for (int x = 0; x <= kBoardWidth; ++x) {
+        for (int y = y0; y <= y1; ++y) {
-            const int px = originX + x * kCellSize;
+            framebuffer.drawPixel(x0, y, true);
-            for (int y = 0; y < kBoardHeight * kCellSize; ++y)
+            framebuffer.drawPixel(x1, y, true);
-                framebuffer.drawPixel(px, originY + y, (x % 5) == 0);
         }
     }
 
@@ -539,15 +582,14 @@ private:
 
         for (int dy = 0; dy < boxSize; ++dy)
             for (int dx = 0; dx < boxSize; ++dx)
-                framebuffer.drawPixel(originX + dx, originY + dy, (dy == 0 || dy == boxSize - 1 || dx == 0 || dx == boxSize - 1));
+                framebuffer.drawPixel(originX + dx, originY + dy,
+                                      (dy == 0 || dy == boxSize - 1 || dx == 0 || dx == boxSize - 1));
 
         const auto& piece = kPieces[state.nextPiece];
         for (const auto& block: piece.rotations[0]) {
-            const int px = originX + (block.x + 1) * blockSize;
+            const int px = originX + (block.x + 1) * blockSize + 1;
-            const int py = originY + (block.y + 1) * blockSize;
+            const int py = originY + (block.y + 1) * blockSize + 1;
-            for (int dy = 1; dy < blockSize - 1; ++dy)
+            drawPatternBlock(px, py, blockSize - 2, state.nextPiece, true);
-                for (int dx = 1; dx < blockSize - 1; ++dx)
-                    framebuffer.drawPixel(px + dx, py + dy, true);
         }
     }
 
@@ -608,7 +650,7 @@ private:
 
 class TetrisFactory final : public cardboy::sdk::IAppFactory {
 public:
-    const char*           name() const override { return kTetrisAppName; }
+    const char*                         name() const override { return kTetrisAppName; }
     std::unique_ptr<cardboy::sdk::IApp> create(AppContext& context) override {
         return std::make_unique<TetrisApp>(context);
     }
@@ -616,8 +658,6 @@ public:
 
 } // namespace
 
-std::unique_ptr<cardboy::sdk::IAppFactory> createTetrisAppFactory() {
+std::unique_ptr<cardboy::sdk::IAppFactory> createTetrisAppFactory() { return std::make_unique<TetrisFactory>(); }
-    return std::make_unique<TetrisFactory>();
-}
 
 } // namespace apps

Firmware/sdk/backend_interface/include/cardboy/sdk/framebuffer_hooks.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+namespace cardboy::sdk {
+
+class FramebufferHooks {
+public:
+    using PreSendHook = void (*)(void* framebuffer, void* userData);
+
+    static void setPreSendHook(PreSendHook hook, void* userData);
+    static void clearPreSendHook();
+    static void invokePreSend(void* framebuffer);
+
+private:
+    static PreSendHook hook_;
+    static void*       userData_;
+};
+
+} // namespace cardboy::sdk

Firmware/sdk/backend_interface/include/cardboy/sdk/platform.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "cardboy/sdk/framebuffer_hooks.hpp"
 #include "input_state.hpp"
 
 #include <concepts>
@@ -67,8 +68,10 @@ public:
     }
 
     __attribute__((always_inline)) void sendFrame(bool clearDrawBuffer = true) {
-        if constexpr (detail::HasSendFrameImpl<Impl>)
+        if constexpr (detail::HasSendFrameImpl<Impl>) {
+            FramebufferHooks::invokePreSend(&impl());
             impl().sendFrame_impl(clearDrawBuffer);
+        }
     }
 
     [[nodiscard]] __attribute__((always_inline)) bool isFrameInFlight() const {

Firmware/sdk/core/CMakeLists.txt

@@ -2,6 +2,9 @@ cmake_minimum_required(VERSION 3.16)
 
 add_library(cardboy_sdk STATIC
         ${CMAKE_CURRENT_SOURCE_DIR}/src/app_system.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/status_bar.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/framebuffer_hooks.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/persistent_settings.cpp
 )
 
 set_target_properties(cardboy_sdk PROPERTIES

Firmware/sdk/core/include/cardboy/sdk/app_system.hpp

@@ -12,6 +12,7 @@ namespace cardboy::sdk {
 class AppSystem {
 public:
     explicit AppSystem(AppContext context);
+    ~AppSystem();
 
     void registerApp(std::unique_ptr<IAppFactory> factory);
     bool startApp(const std::string& name);
@@ -19,12 +20,12 @@ public:
 
     void run();
 
-    [[nodiscard]] std::size_t appCount() const { return factories.size(); }
+    [[nodiscard]] std::size_t        appCount() const { return factories.size(); }
     [[nodiscard]] const IAppFactory* factoryAt(std::size_t index) const;
     [[nodiscard]] std::size_t        indexOfFactory(const IAppFactory* factory) const;
     [[nodiscard]] std::size_t        currentFactoryIndex() const { return activeIndex; }
 
-    [[nodiscard]] const IApp*       currentApp() const { return current.get(); }
+    [[nodiscard]] const IApp*        currentApp() const { return current.get(); }
     [[nodiscard]] const IAppFactory* currentFactory() const { return activeFactory; }
 
 private:
@@ -51,15 +52,15 @@ private:
     TimerRecord*  findTimer(AppTimerHandle handle);
     bool          handlePendingSwitchRequest();
 
-    AppContext                       context;
+    AppContext                                context;
     std::vector<std::unique_ptr<IAppFactory>> factories;
-    std::unique_ptr<IApp>                    current;
+    std::unique_ptr<IApp>                     current;
-    IAppFactory*                             activeFactory = nullptr;
+    IAppFactory*                              activeFactory = nullptr;
     std::size_t                               activeIndex   = static_cast<std::size_t>(-1);
-    std::vector<TimerRecord>                 timers;
+    std::vector<TimerRecord>                  timers;
-    AppTimerHandle                           nextTimerId      = 1;
+    AppTimerHandle                            nextTimerId       = 1;
-    std::uint32_t                            currentGeneration = 0;
+    std::uint32_t                             currentGeneration = 0;
-    InputState                               lastInputState{};
+    InputState                                lastInputState{};
 };
 
 inline AppTimerHandle AppContext::scheduleTimerInternal(std::uint32_t delay_ms, bool repeat) {

Firmware/sdk/core/include/cardboy/sdk/framebuffer_hooks.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <cstddef>
+
+namespace cardboy::sdk {
+
+class FramebufferHooks {
+public:
+    using PreSendHook = void (*)(void* framebuffer, void* userData);
+
+    static void setPreSendHook(PreSendHook hook, void* userData);
+    static void clearPreSendHook();
+    static void invokePreSend(void* framebuffer);
+
+private:
+    static PreSendHook hook_;
+    static void*       userData_;
+};
+
+} // namespace cardboy::sdk

Firmware/sdk/core/include/cardboy/sdk/persistent_settings.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "cardboy/sdk/services.hpp"
+
+namespace cardboy::sdk {
+
+struct PersistentSettings {
+    bool mute           = false;
+    bool autoLightSleep = false;
+};
+
+PersistentSettings loadPersistentSettings(Services* services);
+void               savePersistentSettings(Services* services, const PersistentSettings& settings);
+
+} // namespace cardboy::sdk

Firmware/sdk/core/include/cardboy/sdk/status_bar.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#include "cardboy/sdk/input_state.hpp"
+#include "cardboy/sdk/services.hpp"
+
+#include "cardboy/gfx/font16x8.hpp"
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <string_view>
+
+namespace cardboy::sdk {
+
+class StatusBar {
+public:
+    static StatusBar& instance();
+
+    void setServices(Services* services) { services_ = services; }
+
+    void               setEnabled(bool value);
+    void               toggle();
+    [[nodiscard]] bool isEnabled() const { return enabled_; }
+
+    void setCurrentAppName(std::string_view name);
+
+    [[nodiscard]] bool handleToggleInput(const InputState& current, const InputState& previous);
+
+    template<typename Framebuffer>
+    void renderIfEnabled(Framebuffer& fb) {
+        if (!enabled_)
+            return;
+        renderBar(fb);
+    }
+
+private:
+    StatusBar() = default;
+
+    template<typename Framebuffer>
+    void renderBar(Framebuffer& fb) {
+        const int width = fb.width();
+        if (width <= 0)
+            return;
+
+        const int barHeight  = font16x8::kGlyphHeight + 2;
+        const int fillHeight = std::min(barHeight, fb.height());
+        if (fillHeight <= 0)
+            return;
+
+        const std::string leftText  = prepareLeftText(width);
+        const std::string rightText = prepareRightText();
+
+        for (int y = 0; y < fillHeight; ++y) {
+            for (int x = 0; x < width; ++x)
+                fb.drawPixel(x, y, true);
+        }
+
+        for (int x = 0; x < width; ++x)
+            fb.drawPixel(x, 0, false);
+
+        const int textY            = 1;
+        const int bottomSeparatorY = textY + font16x8::kGlyphHeight + 1;
+        if (bottomSeparatorY < fillHeight) {
+            for (int x = 0; x < width; ++x)
+                fb.drawPixel(x, bottomSeparatorY, (x % 2) != 0);
+        }
+
+        const int leftX = 2;
+        if (!leftText.empty())
+            font16x8::drawText(fb, leftX, textY, leftText, 1, false, 1);
+
+        if (!rightText.empty()) {
+            int       rightWidth = font16x8::measureText(rightText, 1, 1);
+            int       rightX     = width - rightWidth - 2;
+            const int minRightX  = leftX + font16x8::measureText(leftText, 1, 1) + 6;
+            if (rightX < minRightX)
+                rightX = std::max(minRightX, width / 2);
+            if (rightX < width)
+                font16x8::drawText(fb, rightX, textY, rightText, 1, false, 1);
+        }
+    }
+
+    [[nodiscard]] std::string prepareLeftText(int displayWidth) const;
+    [[nodiscard]] std::string prepareRightText() const;
+
+    bool        enabled_  = false;
+    Services*   services_ = nullptr;
+    std::string appName_{};
+};
+
+} // namespace cardboy::sdk

Firmware/sdk/core/src/app_system.cpp

@@ -1,4 +1,6 @@
 #include "cardboy/sdk/app_system.hpp"
+#include "cardboy/sdk/framebuffer_hooks.hpp"
+#include "cardboy/sdk/status_bar.hpp"
 
 #include <algorithm>
 #include <limits>
@@ -12,9 +14,25 @@ namespace {
 }
 
 constexpr std::uint32_t kIdlePollMs = 16;
+
+template<typename Framebuffer>
+void statusBarPreSendHook(void* framebuffer, void* userData) {
+    auto* fb     = static_cast<Framebuffer*>(framebuffer);
+    auto* status = static_cast<StatusBar*>(userData);
+    if (fb && status)
+        status->renderIfEnabled(*fb);
+}
 } // namespace
 
-AppSystem::AppSystem(AppContext ctx) : context(std::move(ctx)) { context.system = this; }
+AppSystem::AppSystem(AppContext ctx) : context(std::move(ctx)) {
+    context.system  = this;
+    auto& statusBar = StatusBar::instance();
+    statusBar.setServices(context.services);
+    using FBType = typename AppContext::Framebuffer;
+    FramebufferHooks::setPreSendHook(&statusBarPreSendHook<FBType>, &statusBar);
+}
+
+AppSystem::~AppSystem() { FramebufferHooks::clearPreSendHook(); }
 
 void AppSystem::registerApp(std::unique_ptr<IAppFactory> factory) {
     if (!factory)
@@ -53,6 +71,8 @@ bool AppSystem::startAppByIndex(std::size_t index) {
     clearTimersForCurrentApp();
     current        = std::move(app);
     lastInputState = context.input.readState();
+    StatusBar::instance().setServices(context.services);
+    StatusBar::instance().setCurrentAppName(activeFactory ? activeFactory->name() : "");
     current->onStart();
     return true;
 }
@@ -71,8 +91,10 @@ void AppSystem::run() {
         const std::uint32_t now = context.clock.millis();
         processDueTimers(now, events);
 
-        const InputState inputNow = context.input.readState();
+        const InputState inputNow               = context.input.readState();
-        if (inputsDiffer(inputNow, lastInputState)) {
+        const bool       consumedByStatusToggle = StatusBar::instance().handleToggleInput(inputNow, lastInputState);
+
+        if (!consumedByStatusToggle && inputsDiffer(inputNow, lastInputState)) {
             AppEvent evt{};
             evt.type            = AppEventType::Button;
             evt.timestamp_ms    = now;
@@ -80,6 +102,8 @@ void AppSystem::run() {
             evt.button.previous = lastInputState;
             events.push_back(evt);
             lastInputState = inputNow;
+        } else if (consumedByStatusToggle) {
+            lastInputState = inputNow;
         }
 
         for (const auto& evt: events) {
@@ -228,4 +252,3 @@ bool AppSystem::handlePendingSwitchRequest() {
 }
 
 } // namespace cardboy::sdk
-

Firmware/sdk/core/src/framebuffer_hooks.cpp

@@ -0,0 +1,23 @@
+#include "cardboy/sdk/framebuffer_hooks.hpp"
+
+namespace cardboy::sdk {
+
+FramebufferHooks::PreSendHook FramebufferHooks::hook_     = nullptr;
+void*                         FramebufferHooks::userData_ = nullptr;
+
+void FramebufferHooks::setPreSendHook(PreSendHook hook, void* userData) {
+    hook_     = hook;
+    userData_ = userData;
+}
+
+void FramebufferHooks::clearPreSendHook() {
+    hook_     = nullptr;
+    userData_ = nullptr;
+}
+
+void FramebufferHooks::invokePreSend(void* framebuffer) {
+    if (hook_)
+        hook_(framebuffer, userData_);
+}
+
+} // namespace cardboy::sdk

Firmware/sdk/core/src/persistent_settings.cpp

@@ -0,0 +1,40 @@
+#include "cardboy/sdk/persistent_settings.hpp"
+
+#include <cstdint>
+#include <string_view>
+
+namespace cardboy::sdk {
+
+namespace {
+constexpr std::string_view kNamespace         = "settings";
+constexpr std::string_view kMuteKey           = "mute";
+constexpr std::string_view kAutoLightSleepKey = "autosleep";
+
+[[nodiscard]] std::uint32_t boolToStorage(bool value) { return value ? 1U : 0U; }
+[[nodiscard]] bool          storageToBool(std::uint32_t value) { return value != 0U; }
+} // namespace
+
+PersistentSettings loadPersistentSettings(Services* services) {
+    PersistentSettings settings{};
+    if (!services || !services->storage)
+        return settings;
+
+    std::uint32_t raw = 0;
+    if (services->storage->readUint32(kNamespace, kMuteKey, raw))
+        settings.mute = storageToBool(raw);
+
+    if (services->storage->readUint32(kNamespace, kAutoLightSleepKey, raw))
+        settings.autoLightSleep = storageToBool(raw);
+
+    return settings;
+}
+
+void savePersistentSettings(Services* services, const PersistentSettings& settings) {
+    if (!services || !services->storage)
+        return;
+
+    services->storage->writeUint32(kNamespace, kMuteKey, boolToStorage(settings.mute));
+    services->storage->writeUint32(kNamespace, kAutoLightSleepKey, boolToStorage(settings.autoLightSleep));
+}
+
+} // namespace cardboy::sdk

Firmware/sdk/core/src/status_bar.cpp

@@ -0,0 +1,81 @@
+#include "cardboy/sdk/status_bar.hpp"
+
+#include <algorithm>
+#include <cctype>
+#include <cmath>
+#include <cstdio>
+
+namespace cardboy::sdk {
+
+StatusBar& StatusBar::instance() {
+    static StatusBar bar;
+    return bar;
+}
+
+void StatusBar::setEnabled(bool value) { enabled_ = value; }
+
+void StatusBar::toggle() {
+    enabled_ = !enabled_;
+    if (services_ && services_->buzzer)
+        services_->buzzer->beepMove();
+}
+
+void StatusBar::setCurrentAppName(std::string_view name) {
+    appName_.assign(name.begin(), name.end());
+    std::transform(appName_.begin(), appName_.end(), appName_.begin(),
+                   [](unsigned char ch) { return static_cast<char>(std::toupper(ch)); });
+}
+
+bool StatusBar::handleToggleInput(const InputState& current, const InputState& previous) {
+    const bool comboNow  = current.start && current.select && current.up;
+    const bool comboPrev = previous.start && previous.select && previous.up;
+    if (comboNow && !comboPrev) {
+        toggle();
+        return true;
+    }
+    return false;
+}
+
+std::string StatusBar::prepareLeftText(int displayWidth) const {
+    std::string text     = appName_.empty() ? std::string("CARDBOY") : appName_;
+    int         maxWidth = std::max(0, displayWidth - 32);
+    while (!text.empty() && font16x8::measureText(text, 1, 1) > maxWidth)
+        text.pop_back();
+    return text;
+}
+
+std::string StatusBar::prepareRightText() const {
+    if (!services_)
+        return {};
+
+    std::string right;
+    if (services_->battery && services_->battery->hasData()) {
+        const float current   = services_->battery->current();
+        const float chargeMah = services_->battery->charge();
+        const float fallbackV = services_->battery->voltage();
+        char        buf[64];
+        if (std::isfinite(current) && std::isfinite(chargeMah)) {
+            std::snprintf(buf, sizeof(buf), "cur %.2fmA chr %.2fmAh", static_cast<double>(current),
+                          static_cast<double>(chargeMah));
+        } else {
+            std::snprintf(buf, sizeof(buf), "vol %.2fV", static_cast<double>(fallbackV));
+        }
+        right.assign(buf);
+    }
+
+    if (services_->powerManager && services_->powerManager->isSlowMode()) {
+        if (!right.empty())
+            right.append(" ");
+        right.append("SLOW");
+    }
+
+    if (services_->buzzer && services_->buzzer->isMuted()) {
+        if (!right.empty())
+            right.append(" ");
+        right.append("MUTE");
+    }
+
+    return right;
+}
+
+} // namespace cardboy::sdk

Firmware/sdk/launchers/desktop/src/main.cpp

@@ -1,9 +1,11 @@
 #include "cardboy/apps/clock_app.hpp"
 #include "cardboy/apps/gameboy_app.hpp"
 #include "cardboy/apps/menu_app.hpp"
+#include "cardboy/apps/settings_app.hpp"
 #include "cardboy/apps/tetris_app.hpp"
 #include "cardboy/backend/desktop_backend.hpp"
 #include "cardboy/sdk/app_system.hpp"
+#include "cardboy/sdk/persistent_settings.hpp"
 
 #include <cstdio>
 #include <exception>
@@ -18,7 +20,13 @@ int main() {
         context.services = &runtime.serviceRegistry();
         cardboy::sdk::AppSystem system(context);
 
+        const cardboy::sdk::PersistentSettings persistentSettings =
+                cardboy::sdk::loadPersistentSettings(context.getServices());
+        if (auto* buzzer = context.buzzer())
+            buzzer->setMuted(persistentSettings.mute);
+
         system.registerApp(apps::createMenuAppFactory());
+        system.registerApp(apps::createSettingsAppFactory());
         system.registerApp(apps::createClockAppFactory());
         system.registerApp(apps::createGameboyAppFactory());
         system.registerApp(apps::createTetrisAppFactory());