Merge 3532f90f1e into 3ce11f14ce

docs/emulation.md

@@ -0,0 +1,12 @@
+# Emulation (development)
+
+TODO: write this
+
+Build the program using `env:emulation`, this is required to re-route `Serial.print` to qemu's stdout.
+
+To run it:
+
+```sh
+cd scripts/emulation
+docker compose up
+```

lib/Epub/Epub.cpp

@@ -3,7 +3,7 @@
 #include <FsHelpers.h>
 #include <HardwareSerial.h>
 #include <JpegToBmpConverter.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <ZipFile.h>
 
 #include "Epub/parsers/ContainerParser.h"

lib/Epub/Epub/BookMetadataCache.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include <string>
 

lib/Epub/Epub/Page.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <utility>
 #include <vector>

lib/Epub/Epub/Section.cpp

@@ -1,6 +1,6 @@
 #include "Section.h"
 
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 #include "Page.h"

lib/Epub/Epub/blocks/TextBlock.h

@@ -1,6 +1,6 @@
 #pragma once
 #include <EpdFontFamily.h>
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <list>
 #include <memory>

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -2,7 +2,7 @@
 
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <expat.h>
 
 #include "../Page.h"

lib/GfxRenderer/Bitmap.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <cstdint>
 

lib/GfxRenderer/GfxRenderer.cpp

@@ -10,19 +10,19 @@ void GfxRenderer::rotateCoordinates(const int x, const int y, int* rotatedX, int
       // Logical portrait (480x800) → panel (800x480)
       // Rotation: 90 degrees clockwise
       *rotatedX = y;
-      *rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - x;
+      *rotatedY = HalDisplay::DISPLAY_HEIGHT - 1 - x;
       break;
     }
     case LandscapeClockwise: {
       // Logical landscape (800x480) rotated 180 degrees (swap top/bottom and left/right)
-      *rotatedX = EInkDisplay::DISPLAY_WIDTH - 1 - x;
+      *rotatedX = HalDisplay::DISPLAY_WIDTH - 1 - x;
-      *rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - y;
+      *rotatedY = HalDisplay::DISPLAY_HEIGHT - 1 - y;
       break;
     }
     case PortraitInverted: {
       // Logical portrait (480x800) → panel (800x480)
       // Rotation: 90 degrees counter-clockwise
-      *rotatedX = EInkDisplay::DISPLAY_WIDTH - 1 - y;
+      *rotatedX = HalDisplay::DISPLAY_WIDTH - 1 - y;
       *rotatedY = x;
       break;
     }
@@ -49,14 +49,14 @@ void GfxRenderer::drawPixel(const int x, const int y, const bool state) const {
   rotateCoordinates(x, y, &rotatedX, &rotatedY);
 
   // Bounds checking against physical panel dimensions
-  if (rotatedX < 0 || rotatedX >= EInkDisplay::DISPLAY_WIDTH || rotatedY < 0 ||
+  if (rotatedX < 0 || rotatedX >= HalDisplay::DISPLAY_WIDTH || rotatedY < 0 ||
-      rotatedY >= EInkDisplay::DISPLAY_HEIGHT) {
+      rotatedY >= HalDisplay::DISPLAY_HEIGHT) {
     Serial.printf("[%lu] [GFX] !! Outside range (%d, %d) -> (%d, %d)\n", millis(), x, y, rotatedX, rotatedY);
     return;
   }
 
   // Calculate byte position and bit position
-  const uint16_t byteIndex = rotatedY * EInkDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
+  const uint16_t byteIndex = rotatedY * HalDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
   const uint8_t bitPosition = 7 - (rotatedX % 8);  // MSB first
 
   if (state) {
@@ -392,12 +392,12 @@ void GfxRenderer::invertScreen() const {
     Serial.printf("[%lu] [GFX] !! No framebuffer in invertScreen\n", millis());
     return;
   }
-  for (int i = 0; i < EInkDisplay::BUFFER_SIZE; i++) {
+  for (int i = 0; i < HalDisplay::BUFFER_SIZE; i++) {
     buffer[i] = ~buffer[i];
   }
 }
 
-void GfxRenderer::displayBuffer(const EInkDisplay::RefreshMode refreshMode) const {
+void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const {
   einkDisplay.displayBuffer(refreshMode);
 }
 
@@ -418,13 +418,13 @@ int GfxRenderer::getScreenWidth() const {
     case Portrait:
     case PortraitInverted:
       // 480px wide in portrait logical coordinates
-      return EInkDisplay::DISPLAY_HEIGHT;
+      return HalDisplay::DISPLAY_HEIGHT;
     case LandscapeClockwise:
     case LandscapeCounterClockwise:
       // 800px wide in landscape logical coordinates
-      return EInkDisplay::DISPLAY_WIDTH;
+      return HalDisplay::DISPLAY_WIDTH;
   }
-  return EInkDisplay::DISPLAY_HEIGHT;
+  return HalDisplay::DISPLAY_HEIGHT;
 }
 
 int GfxRenderer::getScreenHeight() const {
@@ -432,13 +432,13 @@ int GfxRenderer::getScreenHeight() const {
     case Portrait:
     case PortraitInverted:
       // 800px tall in portrait logical coordinates
-      return EInkDisplay::DISPLAY_WIDTH;
+      return HalDisplay::DISPLAY_WIDTH;
     case LandscapeClockwise:
     case LandscapeCounterClockwise:
       // 480px tall in landscape logical coordinates
-      return EInkDisplay::DISPLAY_HEIGHT;
+      return HalDisplay::DISPLAY_HEIGHT;
   }
-  return EInkDisplay::DISPLAY_WIDTH;
+  return HalDisplay::DISPLAY_WIDTH;
 }
 
 int GfxRenderer::getSpaceWidth(const int fontId) const {
@@ -640,9 +640,7 @@ void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y
 
 uint8_t* GfxRenderer::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
 
-size_t GfxRenderer::getBufferSize() { return EInkDisplay::BUFFER_SIZE; }
+size_t GfxRenderer::getBufferSize() { return HalDisplay::BUFFER_SIZE; }
-
-void GfxRenderer::grayscaleRevert() const { einkDisplay.grayscaleRevert(); }
 
 void GfxRenderer::copyGrayscaleLsbBuffers() const { einkDisplay.copyGrayscaleLsbBuffers(einkDisplay.getFrameBuffer()); }
 

lib/GfxRenderer/GfxRenderer.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <EInkDisplay.h>
+#include <HalDisplay.h>
 #include <EpdFontFamily.h>
 
 #include <map>
@@ -21,11 +21,11 @@ class GfxRenderer {
 
  private:
   static constexpr size_t BW_BUFFER_CHUNK_SIZE = 8000;  // 8KB chunks to allow for non-contiguous memory
-  static constexpr size_t BW_BUFFER_NUM_CHUNKS = EInkDisplay::BUFFER_SIZE / BW_BUFFER_CHUNK_SIZE;
+  static constexpr size_t BW_BUFFER_NUM_CHUNKS = HalDisplay::BUFFER_SIZE / BW_BUFFER_CHUNK_SIZE;
-  static_assert(BW_BUFFER_CHUNK_SIZE * BW_BUFFER_NUM_CHUNKS == EInkDisplay::BUFFER_SIZE,
+  static_assert(BW_BUFFER_CHUNK_SIZE * BW_BUFFER_NUM_CHUNKS == HalDisplay::BUFFER_SIZE,
                 "BW buffer chunking does not line up with display buffer size");
 
-  EInkDisplay& einkDisplay;
+  HalDisplay& einkDisplay;
   RenderMode renderMode;
   Orientation orientation;
   uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
@@ -36,7 +36,7 @@ class GfxRenderer {
   void rotateCoordinates(int x, int y, int* rotatedX, int* rotatedY) const;
 
  public:
-  explicit GfxRenderer(EInkDisplay& einkDisplay) : einkDisplay(einkDisplay), renderMode(BW), orientation(Portrait) {}
+  explicit GfxRenderer(HalDisplay& einkDisplay) : einkDisplay(einkDisplay), renderMode(BW), orientation(Portrait) {}
   ~GfxRenderer() { freeBwBufferChunks(); }
 
   static constexpr int VIEWABLE_MARGIN_TOP = 9;
@@ -54,7 +54,7 @@ class GfxRenderer {
   // Screen ops
   int getScreenWidth() const;
   int getScreenHeight() const;
-  void displayBuffer(EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH) const;
+  void displayBuffer(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
   // EXPERIMENTAL: Windowed update - display only a rectangular region
   void displayWindow(int x, int y, int width, int height) const;
   void invertScreen() const;
@@ -106,6 +106,6 @@ class GfxRenderer {
   // Low level functions
   uint8_t* getFrameBuffer() const;
   static size_t getBufferSize();
-  void grayscaleRevert() const;
+  // void grayscaleRevert() const; // unused
   void getOrientedViewableTRBL(int* outTop, int* outRight, int* outBottom, int* outLeft) const;
 };

lib/JpegToBmpConverter/JpegToBmpConverter.cpp

@@ -1,7 +1,7 @@
 #include "JpegToBmpConverter.h"
 
 #include <HardwareSerial.h>
-#include <SdFat.h>
+#include <HalStorage.h>
 #include <picojpeg.h>
 
 #include <cstdio>

lib/KOReaderSync/KOReaderCredentialStore.cpp

@@ -2,7 +2,7 @@
 
 #include <HardwareSerial.h>
 #include <MD5Builder.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 // Initialize the static instance

lib/KOReaderSync/KOReaderDocumentId.cpp

@@ -2,7 +2,7 @@
 
 #include <HardwareSerial.h>
 #include <MD5Builder.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 namespace {
 // Extract filename from path (everything after last '/')

lib/Serialization/Serialization.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <iostream>
 

lib/Txt/Txt.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include <memory>
 #include <string>

lib/Xtc/Xtc.cpp

@@ -9,7 +9,7 @@
 
 #include <FsHelpers.h>
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 bool Xtc::load() {
   Serial.printf("[%lu] [XTC] Loading XTC: %s\n", millis(), filepath.c_str());

lib/Xtc/Xtc/XtcParser.cpp

@@ -9,7 +9,7 @@
 
 #include <FsHelpers.h>
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include <cstring>
 

lib/Xtc/Xtc/XtcParser.h

@@ -7,7 +7,7 @@
 
 #pragma once
 
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <functional>
 #include <memory>

lib/ZipFile/ZipFile.cpp

@@ -1,7 +1,7 @@
 #include "ZipFile.h"
 
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <miniz.h>
 
 bool inflateOneShot(const uint8_t* inputBuf, const size_t deflatedSize, uint8_t* outputBuf, const size_t inflatedSize) {

lib/ZipFile/ZipFile.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <SdFat.h>
+#include <HalStorage.h>
 
 #include <string>
 #include <unordered_map>

lib/hal/EmulationUtils.h

@@ -0,0 +1,186 @@
+#pragma once
+
+#include <Arduino.h>
+#include <vector>
+
+namespace EmulationUtils {
+
+// Packet format (from device to host):
+// $$CMD_(COMMAND):[(ARG0)][:(ARG1)][:(ARG2)]$$\n
+// Host response with either a base64-encoded payload or int64, terminated by newline:
+// (BASE64_ENCODED_PAYLOAD)\n
+// 123\n
+
+static const char* CMD_DISPLAY  = "DISPLAY";  // arg0: base64-encoded buffer -- no return value
+static const char* CMD_FS_LIST  = "FS_LIST";  // arg0: path, arg1: max files -- returns list of filenames, one per line, terminated by empty line
+static const char* CMD_FS_READ  = "FS_READ";  // arg0: path, arg1: offset, arg2: length (-1 means read all) -- returns base64-encoded file contents
+static const char* CMD_FS_STAT  = "FS_STAT";  // arg0: path -- return file size int64_t; -1 means not found; -2 means is a directory
+static const char* CMD_FS_WRITE = "FS_WRITE"; // arg0: path, arg1: base64-encoded data, arg2: offset, arg3: is inplace (0/1) -- return int64_t bytes written
+static const char* CMD_FS_MKDIR = "FS_MKDIR"; // arg0: path -- return int64_t: 0=success
+static const char* CMD_FS_RM    = "FS_RM";    // arg0: path -- return int64_t: 0=success
+static const char* CMD_BUTTON   = "BUTTON";   // arg0: action ("read") -- return int64_t: HalInput state bitmask
+
+static std::string base64_encode(const char* buf, unsigned int bufLen);
+static std::vector<uint8_t> base64_decode(const char* encoded_string, unsigned int in_len);
+
+static SemaphoreHandle_t sendMutex = xSemaphoreCreateMutex();
+
+static void sendCmd(const char* cmd, const char* arg0 = nullptr, const char* arg1 = nullptr, const char* arg2 = nullptr, const char* arg3 = nullptr) {
+  xSemaphoreTake(sendMutex, portMAX_DELAY);
+  if (cmd != CMD_BUTTON) {
+    Serial.printf("[%lu] [EMU] Sending command: %s\n", millis(), cmd);
+  }
+  Serial.print("$$CMD_");
+  Serial.print(cmd);
+  if (arg0 != nullptr) {
+    Serial.print(":");
+    Serial.print(arg0);
+  } else {
+    Serial.print(":"); // ensure at least one colon
+  }
+  if (arg1 != nullptr) {
+    Serial.print(":");
+    Serial.print(arg1);
+  }
+  if (arg2 != nullptr) {
+    Serial.print(":");
+    Serial.print(arg2);
+  }
+  if (arg3 != nullptr) {
+    Serial.print(":");
+    Serial.print(arg3);
+  }
+  Serial.print("$$\n");
+  xSemaphoreGive(sendMutex);
+}
+
+static String recvRespStr() {
+  unsigned long startMillis = millis();
+  String line;
+  const unsigned long timeoutMs = 5000;
+  while (millis() - startMillis < (unsigned long)timeoutMs) {
+    if (Serial.available()) {
+      char c = Serial.read();
+      if (c == '\n') {
+        return line;
+      } else {
+        line += c;
+      }
+    }
+  }
+  // should never reach here
+  Serial.println("FATAL: Timeout waiting for response");
+  return String();
+}
+
+static std::vector<uint8_t> recvRespBuf() {
+  String respStr = recvRespStr();
+  return base64_decode(respStr.c_str(), respStr.length());
+}
+
+static int64_t recvRespInt64() {
+  String respStr = recvRespStr();
+  return respStr.toInt();
+}
+
+static const std::string base64_chars =
+             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+             "abcdefghijklmnopqrstuvwxyz"
+             "0123456789+/";
+
+static inline bool is_base64(char c) {
+  return (isalnum(c) || (c == '+') || (c == '/'));
+}
+
+static std::string base64_encode(const char* buf, unsigned int bufLen) {
+  std::string ret;
+  ret.reserve(bufLen * 4 / 3 + 4); // reserve enough space
+  int i = 0;
+  int j = 0;
+  char char_array_3[3];
+  char char_array_4[4];
+
+  while (bufLen--) {
+    char_array_3[i++] = *(buf++);
+    if (i == 3) {
+      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+      char_array_4[3] = char_array_3[2] & 0x3f;
+
+      for(i = 0; (i < 4) ; i++) {
+        ret += base64_chars[char_array_4[i]];
+      }
+      i = 0;
+    }
+  }
+
+  if (i) {
+    for(j = i; j < 3; j++) {
+      char_array_3[j] = '\0';
+    }
+
+    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+    char_array_4[3] = char_array_3[2] & 0x3f;
+
+    for (j = 0; (j < i + 1); j++) {
+      ret += base64_chars[char_array_4[j]];
+    }
+
+    while((i++ < 3)) {
+      ret += '=';
+    }
+  }
+
+  return ret;
+}
+
+static std::vector<uint8_t> base64_decode(const char* encoded_string, unsigned int in_len) {
+  int i = 0;
+  int j = 0;
+  int in_ = 0;
+  char char_array_4[4], char_array_3[3];
+  std::vector<uint8_t> ret;
+
+  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
+    char_array_4[i++] = encoded_string[in_]; in_++;
+    if (i ==4) {
+      for (i = 0; i < 4; i++) {
+        char_array_4[i] = base64_chars.find(char_array_4[i]);
+      }
+
+      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+      for (i = 0; (i < 3); i++) {
+        ret.push_back(char_array_3[i]);
+      }
+      i = 0;
+    }
+  }
+
+  if (i) {
+    for (j = i; j < 4; j++) {
+      char_array_4[j] = 0;
+    }
+
+    for (j = 0; j < 4; j++) {
+      char_array_4[j] = base64_chars.find(char_array_4[j]);
+    }
+
+    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+    for (j = 0; (j < i - 1); j++) {
+      ret.push_back(char_array_3[j]);
+    }
+  }
+
+  return ret;
+}
+
+} // namespace EmulationUtils

lib/hal/HalDisplay.cpp

@@ -0,0 +1,155 @@
+#include <HalDisplay.h>
+#include <EmulationUtils.h>
+#include <string>
+
+HalDisplay::HalDisplay(int8_t sclk, int8_t mosi, int8_t cs, int8_t dc, int8_t rst, int8_t busy) : einkDisplay(sclk, mosi, cs, dc, rst, busy) {
+  if (is_emulated) {
+    emuFramebuffer0 = new uint8_t[BUFFER_SIZE];
+  }
+}
+
+HalDisplay::~HalDisplay() {
+  if (emuFramebuffer0) {
+    delete[] emuFramebuffer0;
+    emuFramebuffer0 = nullptr;
+  }
+}
+
+void HalDisplay::begin() {
+  if (!is_emulated) {
+    einkDisplay.begin();
+  } else {
+    Serial.printf("[%lu] [   ] Emulated display initialized\n", millis());
+    // no-op
+  }
+}
+
+void HalDisplay::clearScreen(uint8_t color) const {
+  if (!is_emulated) {
+    einkDisplay.clearScreen(color);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated clear screen with color 0x%02X\n", millis(), color);
+    memset(emuFramebuffer0, color, BUFFER_SIZE);
+  }
+}
+
+void HalDisplay::drawImage(const uint8_t* imageData, uint16_t x, uint16_t y, uint16_t w, uint16_t h, bool fromProgmem) const {
+  if (!is_emulated) {
+    einkDisplay.drawImage(imageData, x, y, w, h, fromProgmem);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated draw image at (%u, %u) with size %ux%u\n", millis(), x, y, w, h);
+
+    // Calculate bytes per line for the image
+    const uint16_t imageWidthBytes = w / 8;
+
+    // Copy image data to frame buffer
+    for (uint16_t row = 0; row < h; row++) {
+      const uint16_t destY = y + row;
+      if (destY >= DISPLAY_HEIGHT)
+        break;
+
+      const uint16_t destOffset = destY * DISPLAY_WIDTH_BYTES + (x / 8);
+      const uint16_t srcOffset = row * imageWidthBytes;
+
+      for (uint16_t col = 0; col < imageWidthBytes; col++) {
+        if ((x / 8 + col) >= DISPLAY_WIDTH_BYTES)
+          break;
+
+        if (fromProgmem) {
+          emuFramebuffer0[destOffset + col] = pgm_read_byte(&imageData[srcOffset + col]);
+        } else {
+          emuFramebuffer0[destOffset + col] = imageData[srcOffset + col];
+        }
+      }
+    }
+  }
+}
+
+void HalDisplay::displayBuffer(RefreshMode mode) {
+  if (!is_emulated) {
+    einkDisplay.displayBuffer(mode);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated display buffer with mode %d\n", millis(), static_cast<int>(mode));
+    std::string b64 = EmulationUtils::base64_encode(reinterpret_cast<char*>(emuFramebuffer0), BUFFER_SIZE);
+    EmulationUtils::sendCmd(EmulationUtils::CMD_DISPLAY, b64.c_str());
+    // no response expected
+  }
+}
+
+void HalDisplay::refreshDisplay(RefreshMode mode, bool turnOffScreen) {
+  if (!is_emulated) {
+    einkDisplay.refreshDisplay(mode, turnOffScreen);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated refresh display with mode %d, turnOffScreen %d\n", millis(), static_cast<int>(mode), turnOffScreen);
+    // emulated delay
+    if (mode == RefreshMode::FAST_REFRESH) {
+      delay(500);
+    } else if (mode == RefreshMode::HALF_REFRESH) {
+      delay(1000);
+    } else if (mode == RefreshMode::FULL_REFRESH) {
+      delay(2000);
+    }
+  }
+}
+
+void HalDisplay::deepSleep() {
+  if (!is_emulated) {
+    einkDisplay.deepSleep();
+  } else {
+    Serial.printf("[%lu] [   ] Emulated deep sleep\n", millis());
+    // no-op
+  }
+}
+
+uint8_t* HalDisplay::getFrameBuffer() const {
+  if (!is_emulated) {
+    return einkDisplay.getFrameBuffer();
+  } else {
+    return emuFramebuffer0;
+  }
+}
+
+void HalDisplay::copyGrayscaleBuffers(const uint8_t* lsbBuffer, const uint8_t* msbBuffer) {
+  if (!is_emulated) {
+    einkDisplay.copyGrayscaleBuffers(lsbBuffer, msbBuffer);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated copy grayscale buffers\n", millis());
+    // TODO: not sure what this does
+  }
+}
+
+void HalDisplay::copyGrayscaleLsbBuffers(const uint8_t* lsbBuffer) {
+  if (!is_emulated) {
+    einkDisplay.copyGrayscaleLsbBuffers(lsbBuffer);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated copy grayscale LSB buffers\n", millis());
+    // TODO: not sure what this does
+  }
+}
+
+void HalDisplay::copyGrayscaleMsbBuffers(const uint8_t* msbBuffer) {
+  if (!is_emulated) {
+    einkDisplay.copyGrayscaleMsbBuffers(msbBuffer);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated copy grayscale MSB buffers\n", millis());
+    // TODO: not sure what this does
+  }
+}
+
+void HalDisplay::cleanupGrayscaleBuffers(const uint8_t* bwBuffer) {
+  if (!is_emulated) {
+    einkDisplay.cleanupGrayscaleBuffers(bwBuffer);
+  } else {
+    Serial.printf("[%lu] [   ] Emulated cleanup grayscale buffers\n", millis());
+    // TODO: not sure what this does
+  }
+}
+
+void HalDisplay::displayGrayBuffer() {
+  if (!is_emulated) {
+    einkDisplay.displayGrayBuffer();
+  } else {
+    Serial.printf("[%lu] [   ] Emulated display gray buffer\n", millis());
+    // TODO: not sure what this does
+  }
+}

lib/hal/HalDisplay.h

@@ -0,0 +1,57 @@
+#pragma once
+#include <EInkDisplay.h>
+#include <Arduino.h>
+#include <SPI.h>
+
+class HalDisplay {
+ public:
+  // Constructor with pin configuration
+  HalDisplay(int8_t sclk, int8_t mosi, int8_t cs, int8_t dc, int8_t rst, int8_t busy);
+
+  // Destructor
+  ~HalDisplay();
+
+  // Refresh modes (guarded to avoid redefinition in test builds)
+  using RefreshMode = EInkDisplay::RefreshMode;
+  static constexpr EInkDisplay::RefreshMode FULL_REFRESH = EInkDisplay::FULL_REFRESH;
+  static constexpr EInkDisplay::RefreshMode HALF_REFRESH = EInkDisplay::HALF_REFRESH;
+  static constexpr EInkDisplay::RefreshMode FAST_REFRESH = EInkDisplay::FAST_REFRESH;
+
+  // Initialize the display hardware and driver
+  void begin();
+
+  // Display dimensions
+  static constexpr uint16_t DISPLAY_WIDTH = 800;
+  static constexpr uint16_t DISPLAY_HEIGHT = 480;
+  static constexpr uint16_t DISPLAY_WIDTH_BYTES = DISPLAY_WIDTH / 8;
+  static constexpr uint32_t BUFFER_SIZE = DISPLAY_WIDTH_BYTES * DISPLAY_HEIGHT;
+
+  // Frame buffer operations
+  void clearScreen(uint8_t color = 0xFF) const;
+  void drawImage(const uint8_t* imageData, uint16_t x, uint16_t y, uint16_t w, uint16_t h, bool fromProgmem = false) const;
+
+  void displayBuffer(RefreshMode mode = RefreshMode::FAST_REFRESH);
+  void refreshDisplay(RefreshMode mode = RefreshMode::FAST_REFRESH, bool turnOffScreen = false);
+
+  // Power management
+  void deepSleep();
+
+  // Access to frame buffer
+  uint8_t* getFrameBuffer() const;
+
+  void copyGrayscaleBuffers(const uint8_t* lsbBuffer, const uint8_t* msbBuffer);
+  void copyGrayscaleLsbBuffers(const uint8_t* lsbBuffer);
+  void copyGrayscaleMsbBuffers(const uint8_t* msbBuffer);
+  void cleanupGrayscaleBuffers(const uint8_t* bwBuffer);
+
+  void displayGrayBuffer();
+
+ private:
+  bool is_emulated = CROSSPOINT_EMULATED;
+
+  // real display implementation
+  EInkDisplay einkDisplay;
+
+  // emulated display implementation
+  uint8_t* emuFramebuffer0 = nullptr;
+};

lib/hal/HalInput.cpp

@@ -0,0 +1,122 @@
+#include "HalInput.h"
+#include "EmulationUtils.h"
+#include <esp_sleep.h>
+
+void HalInput::begin() {
+#if CROSSPOINT_EMULATED == 0
+  inputMgr.begin();
+#endif
+}
+
+void HalInput::update() {
+#if CROSSPOINT_EMULATED == 0
+  inputMgr.update();
+#else
+  const unsigned long currentTime = millis();
+
+  EmulationUtils::sendCmd(EmulationUtils::CMD_BUTTON, "read");
+  auto res = EmulationUtils::recvRespInt64();
+  assert(res >= 0);
+
+  const uint8_t state = static_cast<uint8_t>(res);
+
+  // Always clear events first
+  pressedEvents = 0;
+  releasedEvents = 0;
+
+  // Debounce
+  if (state != lastState) {
+    lastDebounceTime = currentTime;
+    lastState = state;
+  }
+
+  static constexpr unsigned long DEBOUNCE_DELAY = 5;
+  if ((currentTime - lastDebounceTime) > DEBOUNCE_DELAY) {
+    if (state != currentState) {
+      // Calculate pressed and released events
+      pressedEvents = state & ~currentState;
+      releasedEvents = currentState & ~state;
+
+      // If pressing buttons and wasn't before, start recording time
+      if (pressedEvents > 0 && currentState == 0) {
+        buttonPressStart = currentTime;
+      }
+
+      // If releasing a button and no other buttons being pressed, record finish time
+      if (releasedEvents > 0 && state == 0) {
+        buttonPressFinish = currentTime;
+      }
+
+      currentState = state;
+    }
+  }
+#endif
+}
+
+bool HalInput::isPressed(uint8_t buttonIndex) const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.isPressed(buttonIndex);
+#else
+  return currentState & (1 << buttonIndex);
+#endif
+}
+
+bool HalInput::wasPressed(uint8_t buttonIndex) const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.wasPressed(buttonIndex);
+#else
+  return currentState & (1 << buttonIndex);
+#endif
+}
+
+bool HalInput::wasAnyPressed() const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.wasAnyPressed();
+#else
+  return pressedEvents > 0;
+#endif
+}
+
+bool HalInput::wasReleased(uint8_t buttonIndex) const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.wasReleased(buttonIndex);
+#else
+  return releasedEvents & (1 << buttonIndex);
+#endif
+}
+
+bool HalInput::wasAnyReleased() const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.wasAnyReleased();
+#else
+  return releasedEvents > 0;
+#endif
+}
+
+unsigned long HalInput::getHeldTime() const {
+#if CROSSPOINT_EMULATED == 0
+  return inputMgr.getHeldTime();
+#else
+  // Still hold a button
+  if (currentState > 0) {
+    return millis() - buttonPressStart;
+  }
+
+  return buttonPressFinish - buttonPressStart;
+#endif
+}
+
+void startDeepSleep(InputManager& inputMgr) {
+#if CROSSPOINT_EMULATED == 0
+  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
+  while (inputMgr.isPressed(InputManager::BTN_POWER)) {
+    delay(50);
+    inputMgr.update();
+  }
+  // Enter Deep Sleep
+  esp_deep_sleep_start();
+#else
+  Serial.println("[   ] GPIO wakeup setup skipped in emulation mode.");
+#endif
+}

lib/hal/HalInput.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <Arduino.h>
+
+#if CROSSPOINT_EMULATED == 0
+#include <InputManager.h>
+#endif
+
+class HalInput {
+#if CROSSPOINT_EMULATED == 0
+  InputManager inputMgr;
+#endif
+
+ public:
+  HalInput() = default;
+  void begin();
+
+  void update();
+  bool isPressed(uint8_t buttonIndex) const;
+  bool wasPressed(uint8_t buttonIndex) const;
+  bool wasAnyPressed() const;
+  bool wasReleased(uint8_t buttonIndex) const;
+  bool wasAnyReleased() const;
+  unsigned long getHeldTime() const;
+
+  // Button indices
+  static constexpr uint8_t BTN_BACK = 0;
+  static constexpr uint8_t BTN_CONFIRM = 1;
+  static constexpr uint8_t BTN_LEFT = 2;
+  static constexpr uint8_t BTN_RIGHT = 3;
+  static constexpr uint8_t BTN_UP = 4;
+  static constexpr uint8_t BTN_DOWN = 5;
+  static constexpr uint8_t BTN_POWER = 6;
+
+ private:
+  // emulation state
+  uint8_t currentState;
+  uint8_t lastState;
+  uint8_t pressedEvents;
+  uint8_t releasedEvents;
+  unsigned long lastDebounceTime;
+  unsigned long buttonPressStart;
+  unsigned long buttonPressFinish;
+};
+
+// TODO @ngxson : this is a trick to avoid changing too many files at once.
+// consider refactoring in a dedicated PR later.
+#if CROSSPOINT_EMULATED == 1
+using InputManager = HalInput;
+#endif
+
+void startDeepSleep(InputManager& inputMgr);

lib/hal/HalStorage.cpp

@@ -0,0 +1,327 @@
+#include "HalStorage.h"
+#include "EmulationUtils.h"
+#include <vector>
+
+#if CROSSPOINT_EMULATED == 0
+#include <SDCardManager.h>
+#endif
+
+HalStorage HalStorage::instance;
+
+HalStorage::HalStorage() {}
+
+bool HalStorage::begin() {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.begin();
+#else
+  // no-op
+  return true;
+#endif
+}
+
+bool HalStorage::ready() const {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.ready();
+#else
+  // no-op
+  return true;
+#endif
+}
+
+std::vector<String> HalStorage::listFiles(const char* path, int maxFiles) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.listFiles(path, maxFiles);
+#else
+  Serial.printf("[%lu] [FS ] Emulated listFiles: %s\n", millis(), path);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_LIST, path);
+  std::vector<String> output;
+  for (int i = 0; i < maxFiles; ++i) {
+    auto resp = EmulationUtils::recvRespStr();
+    if (resp.length() == 0) {
+      break;
+    }
+    output.push_back(resp);
+  }
+  return output;
+#endif
+}
+
+String HalStorage::readFile(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.readFile(path);
+#else
+  Serial.printf("[%lu] [FS ] Emulated readFile: %s\n", millis(), path);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_READ, path, "0", "-1");
+  return EmulationUtils::recvRespStr();
+#endif
+}
+
+static int64_t getFileSizeEmulated(const char* path) {
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_STAT, path);
+  return EmulationUtils::recvRespInt64();
+}
+
+bool HalStorage::readFileToStream(const char* path, Print& out, size_t chunkSize) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.readFileToStream(path, out, chunkSize);
+#else
+  Serial.printf("[%lu] [FS ] Emulated readFileToStream: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  if (size == -1) {
+    Serial.printf("[%lu] [FS ] File not found: %s\n", millis(), path);
+    return false;
+  }
+  if (size == -2) {
+    Serial.printf("[%lu] [FS ] Path is a directory, not a file: %s\n", millis(), path);
+    return false;
+  }
+  size_t bytesRead = 0;
+  while (bytesRead < static_cast<size_t>(size)) {
+    size_t toRead = std::min(chunkSize, static_cast<size_t>(size) - bytesRead);
+    EmulationUtils::sendCmd(EmulationUtils::CMD_FS_READ, path, String(bytesRead).c_str(), String(toRead).c_str());
+    auto buf = EmulationUtils::recvRespBuf();
+    out.write(buf.data(), buf.size());
+    bytesRead += buf.size();
+  }
+  return true;
+#endif
+}
+
+size_t HalStorage::readFileToBuffer(const char* path, char* buffer, size_t bufferSize, size_t maxBytes) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.readFileToBuffer(path, buffer, bufferSize, maxBytes);
+#else
+  Serial.printf("[%lu] [FS ] Emulated readFileToBuffer: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  if (size == -1) {
+    Serial.printf("[%lu] [FS ] File not found: %s\n", millis(), path);
+    return 0;
+  }
+  if (size == -2) {
+    Serial.printf("[%lu] [FS ] Path is a directory, not a file: %s\n", millis(), path);
+    return 0;
+  }
+  size_t toRead = static_cast<size_t>(size);
+  if (maxBytes > 0 && maxBytes < toRead) {
+    toRead = maxBytes;
+  }
+  if (toRead >= bufferSize) {
+    toRead = bufferSize - 1; // leave space for null terminator
+  }
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_READ, path, "0", String(toRead).c_str());
+  auto buf = EmulationUtils::recvRespBuf();
+  size_t bytesRead = buf.size();
+  memcpy(buffer, buf.data(), bytesRead);
+  buffer[bytesRead] = '\0'; // null-terminate
+  return bytesRead;
+#endif
+}
+
+bool HalStorage::writeFile(const char* path, const String& content) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.writeFile(path, content);
+#else
+  Serial.printf("[%lu] [FS ] Emulated writeFile: %s\n", millis(), path);
+  std::string b64 = EmulationUtils::base64_encode((char*)content.c_str(), content.length());
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_WRITE, path, b64.c_str(), "0", "0");
+  EmulationUtils::recvRespInt64(); // unused for now
+  return true;
+#endif
+}
+
+bool HalStorage::ensureDirectoryExists(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.ensureDirectoryExists(path);
+#else
+  Serial.printf("[%lu] [FS ] Emulated ensureDirectoryExists: %s\n", millis(), path);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_MKDIR, path);
+  EmulationUtils::recvRespInt64(); // unused for now
+  return true;
+#endif
+}
+
+FsFile HalStorage::open(const char* path, const oflag_t oflag) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.open(path, oflag);
+#else
+  // TODO: do we need to check existence or create the file?
+  return FsFile(path, oflag);
+#endif
+}
+
+bool HalStorage::mkdir(const char* path, const bool pFlag) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.mkdir(path, pFlag);
+#else
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_MKDIR, path);
+  EmulationUtils::recvRespInt64(); // unused for now
+  return true;
+#endif
+}
+
+bool HalStorage::exists(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.exists(path);
+#else
+  Serial.printf("[%lu] [FS ] Emulated exists: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  return size != -1;
+#endif
+}
+
+bool HalStorage::remove(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.remove(path);
+#else
+  Serial.printf("[%lu] [FS ] Emulated remove: %s\n", millis(), path);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_RM, path);
+  EmulationUtils::recvRespInt64(); // unused for now
+  return true;
+#endif
+}
+
+bool HalStorage::rmdir(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.rmdir(path);
+#else
+  Serial.printf("[%lu] [FS ] Emulated rmdir: %s\n", millis(), path);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_RM, path);
+  EmulationUtils::recvRespInt64(); // unused for now
+  return true;
+#endif
+}
+
+bool HalStorage::openFileForRead(const char* moduleName, const char* path, FsFile& file) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.openFileForRead(moduleName, path, file);
+#else
+  Serial.printf("[%lu] [FS ] Emulated openFileForRead: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  if (size == -1) {
+    Serial.printf("[%lu] [FS ] File not found: %s\n", millis(), path);
+    return false;
+  }
+  if (size == -2) {
+    Serial.printf("[%lu] [FS ] Path is a directory, not a file: %s\n", millis(), path);
+    return false;
+  }
+  return true;
+#endif
+}
+
+bool HalStorage::openFileForRead(const char* moduleName, const std::string& path, FsFile& file) {
+  return openFileForRead(moduleName, path.c_str(), file);
+}
+
+bool HalStorage::openFileForRead(const char* moduleName, const String& path, FsFile& file) {
+  return openFileForRead(moduleName, path.c_str(), file);
+}
+
+bool HalStorage::openFileForWrite(const char* moduleName, const char* path, FsFile& file) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.openFileForWrite(moduleName, path, file);
+#else
+  Serial.printf("[%lu] [FS ] Emulated openFileForWrite: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  if (size == -1) {
+    Serial.printf("[%lu] [FS ] File not found: %s\n", millis(), path);
+    return false;
+  }
+  if (size == -2) {
+    Serial.printf("[%lu] [FS ] Path is a directory, not a file: %s\n", millis(), path);
+    return false;
+  }
+  return true;
+#endif
+}
+
+bool HalStorage::openFileForWrite(const char* moduleName, const std::string& path, FsFile& file) {
+  return openFileForWrite(moduleName, path.c_str(), file);
+}
+
+bool HalStorage::openFileForWrite(const char* moduleName, const String& path, FsFile& file) {
+  return openFileForWrite(moduleName, path.c_str(), file);
+}
+
+bool HalStorage::removeDir(const char* path) {
+#if CROSSPOINT_EMULATED == 0
+  return SdMan.removeDir(path);
+#else
+  // to be implemented
+  return false;
+#endif
+}
+
+
+
+#if CROSSPOINT_EMULATED == 1
+//
+// FsFile emulation methods
+//
+
+FsFile::FsFile(const char* path, oflag_t oflag) : path(path), oflag(oflag) {
+  Serial.printf("[%lu] [FS ] Emulated FsFile open: %s\n", millis(), path);
+  auto size = getFileSizeEmulated(path);
+  if (size == -1) {
+    Serial.printf("[%lu] [FS ] File not found: %s\n", millis(), path);
+    open = false;
+    fileSizeBytes = 0;
+  } else if (isDir) {
+    Serial.printf("[%lu] [FS ] Path is a directory: %s\n", millis(), path);
+    open = true;
+    // get directory entries
+    EmulationUtils::sendCmd(EmulationUtils::CMD_FS_LIST, path);
+    dirEntries.clear();
+    while (true) {
+      auto resp = EmulationUtils::recvRespStr();
+      if (resp.length() == 0) {
+        break;
+      }
+      dirEntries.push_back(resp);
+    }
+    Serial.printf("[%lu] [FS ] Directory has %u entries\n", millis(), (unsigned)dirEntries.size());
+    dirIndex = 0;
+    fileSizeBytes = 0;
+  } else {
+    open = true;
+    fileSizeBytes = static_cast<size_t>(size);
+  }
+}
+
+int FsFile::read(void* buf, size_t count) {
+  if (!open || isDir) return -1;
+  size_t bytesAvailable = (fileSizeBytes > filePos) ? (fileSizeBytes - filePos) : 0;
+  if (bytesAvailable == 0) return 0;
+  size_t toRead = std::min(count, bytesAvailable);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_READ, path.c_str(), String(filePos).c_str(), String(toRead).c_str());
+  auto data = EmulationUtils::recvRespBuf();
+  size_t bytesRead = data.size();
+  memcpy(buf, data.data(), bytesRead);
+  filePos += bytesRead;
+  return static_cast<int>(bytesRead);
+}
+
+int FsFile::read() {
+  uint8_t b;
+  int result = read(&b, 1);
+  if (result <= 0) return -1;
+  return b;
+}
+
+size_t FsFile::write(const uint8_t* buffer, size_t size) {
+  if (!open || isDir) return 0;
+  std::string b64 = EmulationUtils::base64_encode((const char*)buffer, size);
+  EmulationUtils::sendCmd(EmulationUtils::CMD_FS_WRITE, path.c_str(), b64.c_str(), String(filePos).c_str(), "1");
+  EmulationUtils::recvRespInt64(); // unused for now
+  filePos += size;
+  if (filePos > fileSizeBytes) {
+    fileSizeBytes = filePos;
+  }
+  return size;
+}
+
+size_t FsFile::write(uint8_t b) {
+  return write(&b, 1);
+}
+
+#endif

lib/hal/HalStorage.h

@@ -0,0 +1,120 @@
+#pragma once
+
+#include <Arduino.h>
+#include <vector>
+
+#if CROSSPOINT_EMULATED == 0
+#include <SDCardManager.h>
+#else
+typedef int oflag_t;
+#define	O_RDONLY	0		/* +1 == FREAD */
+#define	O_WRONLY	1		/* +1 == FWRITE */
+#define	O_RDWR		2		/* +1 == FREAD|FWRITE */
+
+class FsFile : public Print {
+  String path;
+  String name;
+  oflag_t oflag; // unused for now
+  bool open = false;
+  // directory state
+  bool isDir = false;
+  std::vector<String> dirEntries;
+  size_t dirIndex = 0;
+  // file state
+  size_t filePos = 0;
+  size_t fileSizeBytes = 0;
+ public:
+  FsFile() = default;
+  FsFile(const char* path, oflag_t oflag);
+  ~FsFile() = default;
+
+  void flush() { /* no-op */ }
+  size_t getName(char* name, size_t len) {
+    String n = path;
+    if (n.length() >= len) {
+      n = n.substring(0, len - 1);
+    }
+    n.toCharArray(name, len);
+    return n.length();
+  }
+  size_t size() { return fileSizeBytes; }
+  size_t fileSize() { return size(); }
+  size_t seek(size_t pos) { 
+    filePos = pos; 
+    return filePos; 
+  }
+  size_t seekCur(int64_t offset) { return seek(filePos + offset); }
+  size_t seekSet(size_t offset) { return seek(offset); }
+  int available() const { return (fileSizeBytes > filePos) ? (fileSizeBytes - filePos) : 0; }
+  size_t position() const { return filePos; }
+  int read(void* buf, size_t count);
+  int read(); // read a single byte
+  size_t write(const uint8_t* buffer, size_t size);
+  size_t write(uint8_t b) override;
+  bool isDirectory() const { return isDir; }
+  int rewindDirectory() {
+    if (!isDir) return -1;
+    dirIndex = 0;
+    return 0;
+  }
+  bool close() { open = false; return true; }
+  FsFile openNextFile() {
+    if (!isDir || dirIndex >= dirEntries.size()) {
+      return FsFile();
+    }
+    FsFile f(dirEntries[dirIndex].c_str(), O_RDONLY);
+    dirIndex++;
+    return f;
+  }
+  bool isOpen() const { return open; }
+  operator bool() const { return isOpen(); }
+};
+#endif
+
+class HalStorage {
+ public:
+  HalStorage();
+  bool begin();
+  bool ready() const;
+  std::vector<String> listFiles(const char* path = "/", int maxFiles = 200);
+  // Read the entire file at `path` into a String. Returns empty string on failure.
+  String readFile(const char* path);
+  // Low-memory helpers:
+  // Stream the file contents to a `Print` (e.g. `Serial`, or any `Print`-derived object).
+  // Returns true on success, false on failure.
+  bool readFileToStream(const char* path, Print& out, size_t chunkSize = 256);
+  // Read up to `bufferSize-1` bytes into `buffer`, null-terminating it. Returns bytes read.
+  size_t readFileToBuffer(const char* path, char* buffer, size_t bufferSize, size_t maxBytes = 0);
+  // Write a string to `path` on the SD card. Overwrites existing file.
+  // Returns true on success.
+  bool writeFile(const char* path, const String& content);
+  // Ensure a directory exists, creating it if necessary. Returns true on success.
+  bool ensureDirectoryExists(const char* path);
+
+  FsFile open(const char* path, const oflag_t oflag = O_RDONLY);
+  bool mkdir(const char* path, const bool pFlag = true);
+  bool exists(const char* path);
+  bool remove(const char* path);
+  bool rmdir(const char* path);
+
+  bool openFileForRead(const char* moduleName, const char* path, FsFile& file);
+  bool openFileForRead(const char* moduleName, const std::string& path, FsFile& file);
+  bool openFileForRead(const char* moduleName, const String& path, FsFile& file);
+  bool openFileForWrite(const char* moduleName, const char* path, FsFile& file);
+  bool openFileForWrite(const char* moduleName, const std::string& path, FsFile& file);
+  bool openFileForWrite(const char* moduleName, const String& path, FsFile& file);
+  bool removeDir(const char* path);
+
+ static HalStorage& getInstance() { return instance; }
+
+ private:
+  static HalStorage instance;
+
+  bool is_emulated = CROSSPOINT_EMULATED;
+};
+
+// TODO @ngxson : this is a trick to avoid changing too many files at once.
+// consider refactoring in a dedicated PR later.
+#if CROSSPOINT_EMULATED == 1
+#define SdMan HalStorage::getInstance()
+#endif

platformio.ini

@@ -20,7 +20,6 @@ board_upload.offset_address = 0x10000
 
 build_flags =
   -DARDUINO_USB_MODE=1
-  -DARDUINO_USB_CDC_ON_BOOT=1
   -DMINIZ_NO_ZLIB_COMPATIBLE_NAMES=1
   -DEINK_DISPLAY_SINGLE_BUFFER_MODE=1
   -DDISABLE_FS_H_WARNING=1
@@ -54,9 +53,21 @@ extends = base
 build_flags =
   ${base.build_flags}
   -DCROSSPOINT_VERSION=\"${crosspoint.version}-dev\"
+  -DCROSSPOINT_EMULATED=0
+  -DARDUINO_USB_CDC_ON_BOOT=1
+
+[env:emulation]
+extends = base
+build_flags =
+  ${base.build_flags}
+  -DCROSSPOINT_VERSION=\"${crosspoint.version}-emu\"
+  -DCROSSPOINT_EMULATED=1
+  -DARDUINO_USB_CDC_ON_BOOT=0 # Disable USB CDC on boot for Serial output via UART
 
 [env:gh_release]
 extends = base
 build_flags =
   ${base.build_flags}
   -DCROSSPOINT_VERSION=\"${crosspoint.version}\"
+  -DCROSSPOINT_EMULATED=0
+  -DARDUINO_USB_CDC_ON_BOOT=1

scripts/emulation/Dockerfile

@@ -0,0 +1,46 @@
+FROM debian:12
+
+WORKDIR /root
+
+ARG DEBIAN_FRONTEND=noninteractive
+ARG ESP_IDF_VERSION=v5.5.2
+ARG ESP_QEMU_VERSION=esp-develop-9.2.2-20250817
+
+# Update container
+RUN apt-get update && apt-get upgrade -y
+
+# Install dependencies
+RUN apt-get install -y git wget flex bison gperf python3 python3-pip python3-setuptools python3-venv cmake ninja-build ccache libffi-dev libssl-dev dfu-util libusb-1.0-0 \
+        libgcrypt20 libglib2.0-0 libpixman-1-0 libsdl2-2.0-0 libslirp0 \
+        libglib2.0-dev libpixman-1-dev libgcrypt20-dev libslirp-dev libsdl2-dev
+
+# Install ESP-IDF
+ENV PATH="~/.local/bin:${PATH}"
+RUN mkdir -p ~/esp && \
+        cd ~/esp && git clone --recursive https://github.com/espressif/esp-idf.git -b ${ESP_IDF_VERSION} --depth 1 -j $(nproc) && \
+        ln -s /usr/bin/python3 /usr/bin/python
+RUN cd ~/esp/esp-idf && export IDF_GITHUB_ASSETS="dl.espressif.com/github_assets" && ./install.sh && /bin/bash -c "source ./export.sh"
+
+# Install qemu
+RUN cd ~/esp/esp-idf && python tools/idf_tools.py install qemu-riscv32 qemu-xtensa
+
+# Or, build qemu from source
+# RUN git clone https://github.com/espressif/qemu.git -b ${ESP_QEMU_VERSION} --depth 1 \
+#         && cd qemu \
+#         && mkdir -p build \
+#         && cd build \
+#         && ../configure --target-list=riscv32-softmmu \
+#                 --enable-gcrypt \
+#                 --enable-slirp \
+#                 --enable-debug \
+#                 --enable-sdl \
+#                 --disable-strip --disable-user \
+#                 --disable-capstone --disable-vnc \
+#                 --disable-gtk \
+#         && make -j $(nproc) vga=no \
+#         && make install
+
+RUN echo "alias idf='source /root/esp/esp-idf/export.sh'" >> .bashrc
+
+# Start from a Bash prompt
+CMD [ "/bin/bash" ]

scripts/emulation/docker-compose.yml

@@ -0,0 +1,35 @@
+services:
+  crosspoint-emulator:
+    build: .
+    container_name: crosspoint-emulator
+    volumes:
+      - ../..:/app:ro
+      - ../../.sdcard:/sdcard:rw
+    tmpfs:
+      - /tmp
+    ports:
+      - "8090:8090"
+    stdin_open: true
+    tty: true
+    stop_signal: SIGKILL
+    entrypoint:
+      - /bin/bash
+      - -c
+      - |
+        set -x;
+        set -e;
+        source /root/esp/esp-idf/export.sh
+
+        cd /tmp
+
+        cp /app/.pio/build/emulation/*.bin .
+        dd if=/dev/zero bs=1M count=16 of=./flash.bin
+        dd if="bootloader.bin" bs=1 count=$(stat -c%s "bootloader.bin") seek=0 conv=notrunc of=./flash.bin
+        dd if="partitions.bin" bs=1 count=$(stat -c%s "partitions.bin") seek=$((16#8000)) conv=notrunc of=./flash.bin
+        dd if="firmware.bin" bs=1 count=$(stat -c%s "firmware.bin") seek=$((16#10000)) conv=notrunc of=./flash.bin
+
+        # TODO: why pip install doesn't work in Dockerfile?
+        python3 -m pip install websockets --break-system-packages
+
+        cp /app/scripts/emulation/web_ui.html .
+        python3 /app/scripts/emulation/server.py

scripts/emulation/server.py

@@ -0,0 +1,549 @@
+import asyncio
+import base64
+import json
+import os
+import re
+import shutil
+import signal
+import sys
+from http import HTTPStatus
+from pathlib import Path
+from typing import Set
+
+import websockets
+from websockets.http11 import Response
+from websockets.server import WebSocketServerProtocol
+
+
+"""
+This script spawns a QEMU process, then forward its stdout and stderr to WebSocket clients.
+"""
+
+
+
+# SD card emulation directory
+sdcard_path = os.environ.get("SDCARD_PATH", "/sdcard")
+if not os.path.exists(sdcard_path):
+  os.makedirs(sdcard_path)
+
+
+class SdCardHandler:
+  """Handle SD card filesystem commands from the emulated device."""
+
+  def __init__(self, base_path: str):
+    self.base_path = base_path
+
+  def _resolve_path(self, path: str) -> str:
+    """Resolve a device path to a host filesystem path."""
+    # Remove leading slash and join with base path
+    if path.startswith("/"):
+      path = path[1:]
+    return os.path.join(self.base_path, path)
+
+  def handle_fs_list(self, path: str, max_files: str = "200") -> list[str]:
+    """List files in a directory. Returns list of filenames."""
+    resolved = self._resolve_path(path)
+    max_count = int(max_files) if max_files else 200
+
+    if not os.path.exists(resolved):
+      return []
+
+    if not os.path.isdir(resolved):
+      return []
+
+    try:
+      entries = []
+      for entry in os.listdir(resolved):
+        if len(entries) >= max_count:
+          break
+        full_path = os.path.join(resolved, entry)
+        # Append "/" for directories to match device behavior
+        if os.path.isdir(full_path):
+          entries.append(entry + "/")
+        else:
+          entries.append(entry)
+      return entries
+    except Exception as e:
+      print(f"[SdCard] Error listing {path}: {e}", file=sys.stderr)
+      return []
+
+  def handle_fs_read(self, path: str, offset: str = "0", length: str = "-1") -> str:
+    """Read file contents. Returns base64-encoded data."""
+    resolved = self._resolve_path(path)
+    offset_int = int(offset) if offset else 0
+    length_int = int(length) if length else -1
+
+    if not os.path.exists(resolved) or os.path.isdir(resolved):
+      return ""
+
+    try:
+      with open(resolved, "rb") as f:
+        if offset_int > 0:
+          f.seek(offset_int)
+        if length_int == -1:
+          data = f.read()
+        else:
+          data = f.read(length_int)
+        return base64.b64encode(data).decode("ascii")
+    except Exception as e:
+      print(f"[SdCard] Error reading {path}: {e}", file=sys.stderr)
+      return ""
+
+  def handle_fs_stat(self, path: str) -> int:
+    """Get file size. Returns -1 if not found, -2 if directory."""
+    resolved = self._resolve_path(path)
+
+    if not os.path.exists(resolved):
+      return -1
+
+    if os.path.isdir(resolved):
+      return -2
+
+    try:
+      return os.path.getsize(resolved)
+    except Exception as e:
+      print(f"[SdCard] Error stat {path}: {e}", file=sys.stderr)
+      return -1
+
+  def handle_fs_write(self, path: str, b64_data: str, offset: str = "0", inplace: str = "0") -> int:
+    """Write data to file. Returns bytes written."""
+    resolved = self._resolve_path(path)
+    offset_int = int(offset) if offset else 0
+    is_inplace = inplace == "1"
+
+    try:
+      data = base64.b64decode(b64_data)
+    except Exception as e:
+      print(f"[SdCard] Error decoding base64 for {path}: {e}", file=sys.stderr)
+      return 0
+
+    try:
+      # Ensure parent directory exists
+      parent = os.path.dirname(resolved)
+      if parent and not os.path.exists(parent):
+        os.makedirs(parent)
+
+      if is_inplace and os.path.exists(resolved):
+        # In-place write at offset
+        with open(resolved, "r+b") as f:
+          f.seek(offset_int)
+          f.write(data)
+      else:
+        # Overwrite or create new file
+        mode = "r+b" if os.path.exists(resolved) and offset_int > 0 else "wb"
+        with open(resolved, mode) as f:
+          if offset_int > 0:
+            f.seek(offset_int)
+          f.write(data)
+
+      return len(data)
+    except Exception as e:
+      print(f"[SdCard] Error writing {path}: {e}", file=sys.stderr)
+      return 0
+
+  def handle_fs_mkdir(self, path: str) -> int:
+    """Create directory. Returns 0 on success."""
+    resolved = self._resolve_path(path)
+
+    try:
+      os.makedirs(resolved, exist_ok=True)
+      return 0
+    except Exception as e:
+      print(f"[SdCard] Error mkdir {path}: {e}", file=sys.stderr)
+      return -1
+
+  def handle_fs_rm(self, path: str) -> int:
+    """Remove file or directory. Returns 0 on success."""
+    resolved = self._resolve_path(path)
+
+    if not os.path.exists(resolved):
+      return -1
+
+    try:
+      if os.path.isdir(resolved):
+        shutil.rmtree(resolved)
+      else:
+        os.remove(resolved)
+      return 0
+    except Exception as e:
+      print(f"[SdCard] Error removing {path}: {e}", file=sys.stderr)
+      return -1
+
+
+# Global SD card handler instance
+sdcard_handler = SdCardHandler(sdcard_path)
+
+
+# WebSocket clients
+connected_clients: Set[WebSocketServerProtocol] = set()
+
+# QEMU process
+qemu_process: asyncio.subprocess.Process | None = None
+
+# Command pattern: $$CMD_(COMMAND):(ARG0)[:(ARG1)][:(ARG2)][:(ARG3)]$$
+CMD_PATTERN = re.compile(r'^\$\$CMD_([A-Z_]+):(.+)\$\$$')
+
+
+def parse_command(message: str) -> tuple[str, list[str]] | None:
+  """Parse a command message. Returns (command, args) or None if not a command."""
+  match = CMD_PATTERN.match(message)
+  if not match:
+    return None
+  command = match.group(1)
+  args_str = match.group(2)
+  # Split args by ':' but the last arg might contain ':'
+  args = args_str.split(':')
+  return (command, args)
+
+
+async def send_response(response: str):
+  """Send a response back to the QEMU process via stdin."""
+  global qemu_process
+  if qemu_process and qemu_process.stdin:
+    qemu_process.stdin.write((response + "\n").encode())
+    await qemu_process.stdin.drain()
+
+
+LAST_DISPLAY_BUFFER = None
+BUTTON_STATE = 0
+
+async def handle_command(command: str, args: list[str]) -> bool:
+  """Handle a command from the device. Returns True if handled."""
+  global sdcard_handler, LAST_DISPLAY_BUFFER, BUTTON_STATE
+
+  try:
+    if command == "DISPLAY":
+      # Display command - no response needed
+      # arg0: base64-encoded buffer
+      print(f"[Emulator] DISPLAY command received (buffer size: {len(args[0]) if args else 0})", flush=True)
+      LAST_DISPLAY_BUFFER = args[0] if args else None
+      return True
+
+    elif command == "FS_LIST":
+      # arg0: path, arg1: max files (optional)
+      path = args[0] if len(args) > 0 else "/"
+      max_files = args[1] if len(args) > 1 else "200"
+      entries = sdcard_handler.handle_fs_list(path, max_files)
+      print(f"[Emulator] FS_LIST {path} -> {len(entries)} entries", flush=True)
+      # Send each entry as a line, then empty line to terminate
+      for entry in entries:
+        await send_response(entry)
+      await send_response("")  # Empty line terminates the list
+      return True
+
+    elif command == "FS_READ":
+      # arg0: path, arg1: offset, arg2: length
+      path = args[0] if len(args) > 0 else ""
+      offset = args[1] if len(args) > 1 else "0"
+      length = args[2] if len(args) > 2 else "-1"
+      result = sdcard_handler.handle_fs_read(path, offset, length)
+      print(f"[Emulator] FS_READ {path} offset={offset} len={length} -> {len(result)} bytes (b64)", flush=True)
+      await send_response(result)
+      return True
+
+    elif command == "FS_STAT":
+      # arg0: path
+      path = args[0] if len(args) > 0 else ""
+      result = sdcard_handler.handle_fs_stat(path)
+      print(f"[Emulator] FS_STAT {path} -> {result}", flush=True)
+      await send_response(str(result))
+      return True
+
+    elif command == "FS_WRITE":
+      # arg0: path, arg1: base64-encoded data, arg2: offset, arg3: is inplace
+      path = args[0] if len(args) > 0 else ""
+      b64_data = args[1] if len(args) > 1 else ""
+      offset = args[2] if len(args) > 2 else "0"
+      inplace = args[3] if len(args) > 3 else "0"
+      result = sdcard_handler.handle_fs_write(path, b64_data, offset, inplace)
+      print(f"[Emulator] FS_WRITE {path} offset={offset} inplace={inplace} -> {result} bytes", flush=True)
+      await send_response(str(result))
+      return True
+
+    elif command == "FS_MKDIR":
+      # arg0: path
+      path = args[0] if len(args) > 0 else ""
+      result = sdcard_handler.handle_fs_mkdir(path)
+      print(f"[Emulator] FS_MKDIR {path} -> {result}", flush=True)
+      await send_response(str(result))
+      return True
+
+    elif command == "FS_RM":
+      # arg0: path
+      path = args[0] if len(args) > 0 else ""
+      result = sdcard_handler.handle_fs_rm(path)
+      print(f"[Emulator] FS_RM {path} -> {result}", flush=True)
+      await send_response(str(result))
+      return True
+    
+    elif command == "BUTTON":
+      # arg0: action
+      action = args[0]
+      if action != "read":
+        raise ValueError("Only read action is supported")
+      # no log (too frequent)
+      # print(f"[Emulator] BUTTON command received: {action}", flush=True)
+      await send_response(str(BUTTON_STATE))
+      return True
+
+    else:
+      print(f"[Emulator] Unknown command: {command}", flush=True)
+      return False
+
+  except Exception as e:
+    print(f"[Emulator] Error handling command {command}: {e}", file=sys.stderr)
+    return False
+
+
+def process_message(message: str, for_ui: bool) -> str | None:
+  if message.startswith("$$CMD_BUTTON:"):
+    return None # Too frequent, ignore
+  if message.startswith("$$CMD_"):
+    if for_ui:
+      return message
+    else:
+      # $$CMD_(COMMAND)[:(ARG0)][:(ARG1)][:(ARG2)]$$
+      command = message[2:].split(':')[0]
+      return "[Emulator] Received command: " + command
+  return message
+
+
+async def broadcast_message(msg_type: str, data: str):
+  """Broadcast a message to all connected WebSocket clients."""
+  if not connected_clients:
+    return
+
+  message = json.dumps({"type": msg_type, "data": data})
+
+  # Send to all clients, remove disconnected ones
+  disconnected = set()
+  for client in connected_clients:
+    try:
+      await client.send(message)
+    except websockets.exceptions.ConnectionClosed:
+      disconnected.add(client)
+
+  connected_clients.difference_update(disconnected)
+
+
+async def read_stream(stream: asyncio.StreamReader, stream_type: str):
+  """Read from a stream line by line and broadcast to clients."""
+  buffer = b""
+
+  while True:
+    try:
+      chunk = await stream.read(1024)
+      if not chunk:
+        break
+
+      buffer += chunk
+
+      # Process complete lines
+      while b"\n" in buffer:
+        line, buffer = buffer.split(b"\n", 1)
+        try:
+          decoded_line = line.decode("utf-8", errors="replace")
+        except Exception:
+          decoded_line = line.decode("latin-1", errors="replace")
+
+        # Check if this is a command that needs handling
+        parsed = parse_command(decoded_line)
+        if parsed:
+          command, args = parsed
+          await handle_command(command, args)
+          if command == "DISPLAY":
+            await broadcast_message(stream_type, decoded_line)
+          continue
+
+        to_stdio = process_message(decoded_line, for_ui=False)
+        to_ws = process_message(decoded_line, for_ui=True)
+
+        # Forward to parent process
+        if to_stdio is not None:
+          if stream_type == "stdout":
+            print(to_stdio, flush=True)
+          else:
+            print(to_stdio, file=sys.stderr, flush=True)
+
+        # Broadcast to WebSocket clients
+        if to_ws is not None:
+          await broadcast_message(stream_type, to_ws)
+
+    except Exception as e:
+      print(f"Error reading {stream_type}: {e}", file=sys.stderr)
+      break
+
+  # Process remaining buffer
+  if buffer:
+    try:
+      decoded_line = buffer.decode("utf-8", errors="replace")
+    except Exception:
+      decoded_line = buffer.decode("latin-1", errors="replace")
+
+    if stream_type == "stdout":
+      print(decoded_line, flush=True)
+    else:
+      print(decoded_line, file=sys.stderr, flush=True)
+
+    await broadcast_message(stream_type, decoded_line)
+
+
+async def spawn_qemu():
+  """Spawn the QEMU process and capture its output."""
+  global qemu_process
+
+  # Build the command
+  cmd = [
+    "qemu-system-riscv32",
+    "-nographic",
+    "-M", "esp32c3",
+    "-drive", "file=flash.bin,if=mtd,format=raw",
+    # "-global", "driver=timer.esp32c3.timg,property=wdt_disable,value=true", # got panic if we don't disable WDT, why?
+  ]
+
+  # Get working directory from environment or use /tmp
+  work_dir = os.getcwd()
+
+  print(f"Starting QEMU in {work_dir}...", flush=True)
+  print(f"Command: {' '.join(cmd)}", flush=True)
+
+  try:
+    qemu_process = await asyncio.create_subprocess_exec(
+      *cmd,
+      stdout=asyncio.subprocess.PIPE,
+      stderr=asyncio.subprocess.PIPE,
+      stdin=asyncio.subprocess.PIPE,
+      cwd=work_dir,
+      env=os.environ.copy()
+    )
+
+    # Read stdout and stderr concurrently
+    await asyncio.gather(
+      read_stream(qemu_process.stdout, "stdout"),
+      read_stream(qemu_process.stderr, "stderr")
+    )
+
+    # Wait for process to complete
+    await qemu_process.wait()
+    print(f"QEMU process exited with code {qemu_process.returncode}", flush=True)
+
+  except FileNotFoundError:
+    print("Error: qemu-system-riscv32 not found. Make sure it's in PATH.", file=sys.stderr)
+    await broadcast_message("stderr", "Error: qemu-system-riscv32 not found")
+  except Exception as e:
+    print(f"Error spawning QEMU: {e}", file=sys.stderr)
+    await broadcast_message("stderr", f"Error spawning QEMU: {e}")
+
+
+async def websocket_handler(websocket: WebSocketServerProtocol):
+  """Handle a WebSocket connection."""
+  connected_clients.add(websocket)
+  print(f"Client connected. Total clients: {len(connected_clients)}", flush=True)
+
+  try:
+    # Send a welcome message
+    await websocket.send(json.dumps({
+      "type": "info",
+      "data": "Connected to CrossPoint emulator"
+    }))
+
+    # Send the last display buffer if available
+    if LAST_DISPLAY_BUFFER is not None:
+      await websocket.send(json.dumps({
+        "type": "stdout",
+        "data": f"$$CMD_DISPLAY:{LAST_DISPLAY_BUFFER}$$"
+      }))
+
+    # Handle incoming messages (for stdin forwarding and events)
+    async for message in websocket:
+      try:
+        data = json.loads(message)
+        msg_type = data.get("type")
+        
+        if msg_type == "stdin" and qemu_process and qemu_process.stdin:
+          input_data = data.get("data", "")
+          qemu_process.stdin.write((input_data + "\n").encode())
+          await qemu_process.stdin.drain()
+        elif msg_type == "button_state":
+          global BUTTON_STATE
+          BUTTON_STATE = int(data.get("state", "0"))
+          print(f"[WebUI] Button state updated to {BUTTON_STATE}", flush=True)
+        else:
+          # Print any other messages for debugging
+          print(f"[WebUI Message] {message}", flush=True)
+      except json.JSONDecodeError:
+        print(f"[WebUI] Invalid JSON received: {message}", file=sys.stderr)
+      except Exception as e:
+        print(f"Error handling client message: {e}", file=sys.stderr)
+
+  except websockets.exceptions.ConnectionClosed:
+    pass
+  finally:
+    connected_clients.discard(websocket)
+    print(f"Client disconnected. Total clients: {len(connected_clients)}", flush=True)
+
+
+async def main():
+  """Main entry point."""
+  host = os.environ.get("HOST", "0.0.0.0")
+  port = int(os.environ.get("PORT", "8090"))
+
+  print(f"Starting WebSocket server on {host}:{port}", flush=True)
+
+  # Start WebSocket server
+  async with websockets.serve(
+    websocket_handler, host, port,
+    process_request=process_request,
+    origins=None,
+  ):
+    print(f"WebSocket server running on ws://{host}:{port}/ws", flush=True)
+    print(f"Web UI available at http://{host}:{port}/", flush=True)
+
+    # Spawn QEMU process
+    await spawn_qemu()
+
+
+def signal_handler(signum, frame):
+  """Handle shutdown signals."""
+  print("\nShutting down...", flush=True)
+  if qemu_process:
+    qemu_process.terminate()
+  sys.exit(0)
+
+
+def process_request(connection, request):
+  """Handle HTTP requests for serving static files."""
+  path = request.path
+
+  if path == "/" or path == "/web_ui.html":
+    # Serve the web_ui.html file
+    html_path = Path(__file__).parent / "web_ui.html"
+    try:
+      content = html_path.read_bytes()
+      return Response(
+        HTTPStatus.OK,
+        "OK",
+        websockets.Headers([
+          ("Content-Type", "text/html; charset=utf-8"),
+          ("Content-Length", str(len(content))),
+        ]),
+        content
+      )
+    except FileNotFoundError:
+      return Response(HTTPStatus.NOT_FOUND, "Not Found", websockets.Headers(), b"web_ui.html not found")
+
+  if path == "/ws":
+    # Return None to continue with WebSocket handshake
+    return None
+
+  # Return 404 for other paths
+  return Response(HTTPStatus.NOT_FOUND, "Not Found", websockets.Headers(), b"Not found")
+
+
+if __name__ == "__main__":
+  # Set up signal handlers
+  signal.signal(signal.SIGINT, signal_handler)
+  signal.signal(signal.SIGTERM, signal_handler)
+
+  # Run the main loop
+  asyncio.run(main())

scripts/emulation/web_ui.html

@@ -0,0 +1,242 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>CrossPoint Emulator</title>
+  <style>
+    body {
+      font-family: monospace;
+      margin: 0;
+      height: 100vh;
+      background-color: #bbb;
+      display: flex;
+      justify-content: center;
+    }
+
+    button {
+      font-size: 1.2em;
+      padding: 0.5em 1em;
+      margin: 0.2em;
+    }
+
+    .container {
+      display: flex;
+      flex-direction: row;
+      justify-content: center;
+      align-items: center;
+      width: 100%;
+      height: 100%;
+      max-width: 1200px;
+    }
+
+    .display, .control {
+      width: 50%;
+      height: 95vh;
+      display: flex;
+      justify-content: center;
+      align-items: center;
+      padding-left: 2em;
+      padding-right: 2em;
+    }
+
+    .display > canvas {
+      max-height: 100%;
+    }
+
+    .control {
+      flex-direction: column;
+      gap: 1em;
+    }
+    
+    .control > .ctrl {
+      padding-top: 2em;
+      padding-bottom: 2em;
+    }
+
+    .control > #output {
+      height: 100%;
+      width: 100%;
+      padding: 10px;
+      overflow-y: scroll;
+      border: 1px solid #555;
+    }
+  </style>
+</head>
+<body>
+  <div class="container">
+    <div class="display">
+      <!-- Display -->
+      <canvas id="screen" width="480" height="800" style="border:1px solid #555;"></canvas>
+    </div>
+
+    <div class="control">
+      <!-- Control + Log -->
+      <div class="ctrl">
+        <button id="btn0">Btn 0</button>
+        <button id="btn1">Btn 1</button>
+        &nbsp;&nbsp;&nbsp;
+        <button id="btn2">Btn 2</button>
+        <button id="btn3">Btn 3</button>
+        &nbsp;&nbsp;&nbsp;
+        <button id="btnU">Btn Up</button>
+        <button id="btnD">Btn Down</button>
+        &nbsp;&nbsp;&nbsp;
+        <button id="btnP">Btn Power</button>
+      </div>
+      <div id="output"></div>
+    </div>
+  </div>
+
+  <script>
+    const output = document.getElementById('output');
+    const screen = document.getElementById('screen');
+    const ctx = screen.getContext('2d');
+
+    let ws = null;
+
+    const MAX_LOG_LINES = 1000;
+    function appendLog(type, message) {
+      const line = document.createElement('div');
+      line.className = type;
+      line.textContent = message;
+      output.appendChild(line);
+      output.scrollTop = output.scrollHeight; // TODO: only scroll if already at bottom
+      while (output.childElementCount > MAX_LOG_LINES) {
+        output.removeChild(output.firstChild);
+      }
+    }
+
+    function drawScreen(b64Data) {
+      // b64Data is a base64-encoded 1-bit per pixel framebuffer
+      // Source buffer is 800x480, with 100 bytes per row (800/8 = 100)
+      // We rotate 90 degrees clockwise to display as 480x800
+      const binaryString = atob(b64Data);
+      const srcWidth = 800;
+      const srcHeight = 480;
+      const srcWidthBytes = srcWidth / 8; // 100 bytes per row
+
+      // After 90° clockwise rotation: new width = srcHeight, new height = srcWidth
+      const dstWidth = srcHeight;  // 480
+      const dstHeight = srcWidth;  // 800
+
+      const imageData = ctx.createImageData(dstWidth, dstHeight);
+      const pixels = imageData.data;
+
+      for (let srcY = 0; srcY < srcHeight; srcY++) {
+        for (let xByte = 0; xByte < srcWidthBytes; xByte++) {
+          const byteIndex = srcY * srcWidthBytes + xByte;
+          const byte = binaryString.charCodeAt(byteIndex);
+
+          // Each byte contains 8 pixels (MSB first)
+          for (let bit = 0; bit < 8; bit++) {
+            const srcX = xByte * 8 + bit;
+
+            // 90° clockwise rotation: (srcX, srcY) -> (srcHeight - 1 - srcY, srcX)
+            const dstX = srcHeight - 1 - srcY;
+            const dstY = srcX;
+
+            const pixelIndex = (dstY * dstWidth + dstX) * 4;
+
+            // Bit 1 = white (0xFF), Bit 0 = black (0x00)
+            const isWhite = (byte >> (7 - bit)) & 1;
+            const color = isWhite ? 255 : 0;
+
+            pixels[pixelIndex] = color;     // R
+            pixels[pixelIndex + 1] = color; // G
+            pixels[pixelIndex + 2] = color; // B
+            pixels[pixelIndex + 3] = 255;   // A
+          }
+        }
+      }
+
+      ctx.putImageData(imageData, 0, 0);
+    }
+
+    let btn0Pressed = false;
+    let btn1Pressed = false;
+    let btn2Pressed = false;
+    let btn3Pressed = false;
+    let btnUpPressed = false;
+    let btnDownPressed = false;
+    let btnPowerPressed = false;
+
+    let buttonState = 0;
+    function sendButtonState() {
+      if (ws && ws.readyState === WebSocket.OPEN) {
+        ws.send(JSON.stringify({
+          type: 'button_state',
+          state: buttonState
+        }));
+        appendLog('info', `Sent button state: ${buttonState}`);
+      } else {
+        appendLog('error', 'WebSocket not connected');
+      }
+    }
+
+    function setupButtonHandler(buttonId, bitIndex) {
+      const button = document.getElementById(buttonId);
+      button.onmousedown = () => {
+        buttonState ^= (1 << bitIndex);
+        sendButtonState();
+      };
+      button.onmouseup = () => {
+        buttonState &= ~(1 << bitIndex);
+        sendButtonState();
+      };
+    }
+    setupButtonHandler('btn0', 0);
+    setupButtonHandler('btn1', 1);
+    setupButtonHandler('btn2', 2);
+    setupButtonHandler('btn3', 3);
+    setupButtonHandler('btnU', 4);
+    setupButtonHandler('btnD', 5);
+    setupButtonHandler('btnP', 6);
+
+    function connect() {
+      const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
+      const wsUrl = `${protocol}//${window.location.host}/ws`;
+
+      appendLog('info', `Connecting to ${wsUrl}...`);
+
+      ws = new WebSocket(wsUrl);
+
+      ws.onopen = () => {
+        appendLog('info', 'Connected');
+      };
+
+      ws.onmessage = (event) => {
+        try {
+          const msg = JSON.parse(event.data);
+          if (msg.data.startsWith('$$CMD_')) {
+            // $$CMD_(COMMAND)[:(ARG0)][:(ARG1)][:(ARG2)]$$
+            const parts = msg.data.slice(2, -2).split(':');
+            const command = parts[0];
+            appendLog('cmd', `Received command: ${command}`);
+            if (command === 'CMD_DISPLAY') {
+              drawScreen(parts[1]);
+            }
+          } else {
+            appendLog(msg.type, msg.data);
+          }
+        } catch (e) {
+          appendLog('stdout', event.data);
+        }
+      };
+
+      ws.onclose = () => {
+        appendLog('info', 'Disconnected');
+        setTimeout(connect, 3000);
+      };
+    }
+
+    window.onload = () => {
+      connect();
+
+      // fill canvas with black initially
+      ctx.fillStyle = 'white';
+      ctx.fillRect(0, 0, screen.width, screen.height);
+    };
+  </script>
+</body>
+</html>

src/Battery.h

@@ -3,4 +3,16 @@
 
 #define BAT_GPIO0 0  // Battery voltage
 
-static BatteryMonitor battery(BAT_GPIO0);
+class Battery {
+ public:
+  uint16_t readPercentage() const {
+#if CROSSPOINT_EMULATED == 0
+    static const BatteryMonitor hwBattery = BatteryMonitor(BAT_GPIO0);
+    return hwBattery.readPercentage();
+#else
+    return 100;
+#endif
+  }
+};
+
+static Battery battery;

src/CrossPointSettings.cpp

@@ -1,7 +1,7 @@
 #include "CrossPointSettings.h"
 
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 #include <cstring>

src/CrossPointState.cpp

@@ -1,7 +1,7 @@
 #include "CrossPointState.h"
 
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 namespace {

src/MappedInputManager.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <InputManager.h>
+#include <HalInput.h>
 
 class MappedInputManager {
  public:

src/RecentBooksStore.cpp

@@ -1,7 +1,7 @@
 #include "RecentBooksStore.h"
 
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 #include <algorithm>

src/WifiCredentialStore.cpp

@@ -1,7 +1,7 @@
 #include "WifiCredentialStore.h"
 
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 
 // Initialize the static instance

src/activities/boot_sleep/SleepActivity.cpp

@@ -2,7 +2,7 @@
 
 #include <Epub.h>
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Txt.h>
 #include <Xtc.h>
 
@@ -133,7 +133,7 @@ void SleepActivity::renderDefaultSleepScreen() const {
     renderer.invertScreen();
   }
 
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 }
 
 void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
@@ -180,7 +180,7 @@ void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
   Serial.printf("[%lu] [SLP] drawing to %d x %d\n", millis(), x, y);
   renderer.clearScreen();
   renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight, cropX, cropY);
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 
   if (bitmap.hasGreyscale()) {
     bitmap.rewindToData();
@@ -270,5 +270,5 @@ void SleepActivity::renderCoverSleepScreen() const {
 
 void SleepActivity::renderBlankSleepScreen() const {
   renderer.clearScreen();
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 }

src/activities/home/HomeActivity.cpp

@@ -3,7 +3,7 @@
 #include <Bitmap.h>
 #include <Epub.h>
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Xtc.h>
 
 #include <cstring>

src/activities/home/MyLibraryActivity.cpp

@@ -1,7 +1,7 @@
 #include "MyLibraryActivity.h"
 
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include <algorithm>
 

src/activities/network/CalibreWirelessActivity.cpp

@@ -2,7 +2,7 @@
 
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <WiFi.h>
 
 #include <cstring>

src/activities/network/CalibreWirelessActivity.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <WiFiClient.h>
 #include <WiFiUdp.h>
 #include <freertos/FreeRTOS.h>

src/activities/reader/EpubReaderActivity.cpp

@@ -3,7 +3,7 @@
 #include <Epub/Page.h>
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
@@ -322,7 +322,7 @@ void EpubReaderActivity::renderScreen() {
       auto progressCallback = [this, barX, barY, barWidth, barHeight](int progress) {
         const int fillWidth = (barWidth - 2) * progress / 100;
         renderer.fillRect(barX + 1, barY + 1, fillWidth, barHeight - 2, true);
-        renderer.displayBuffer(EInkDisplay::FAST_REFRESH);
+        renderer.displayBuffer(HalDisplay::FAST_REFRESH);
       };
 
       if (!section->createSectionFile(SETTINGS.getReaderFontId(), SETTINGS.getReaderLineCompression(),
@@ -392,7 +392,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
   page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/reader/TxtReaderActivity.cpp

@@ -1,7 +1,7 @@
 #include "TxtReaderActivity.h"
 
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <Serialization.h>
 #include <Utf8.h>
 
@@ -237,7 +237,7 @@ void TxtReaderActivity::buildPageIndex() {
       // Fill progress bar
       const int fillWidth = (barWidth - 2) * progressPercent / 100;
       renderer.fillRect(barX + 1, barY + 1, fillWidth, barHeight - 2, true);
-      renderer.displayBuffer(EInkDisplay::FAST_REFRESH);
+      renderer.displayBuffer(HalDisplay::FAST_REFRESH);
     }
 
     // Yield to other tasks periodically
@@ -465,7 +465,7 @@ void TxtReaderActivity::renderPage() {
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
 
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/reader/XtcReaderActivity.cpp

@@ -9,7 +9,7 @@
 
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
@@ -269,7 +269,7 @@ void XtcReaderActivity::renderPage() {
 
     // Display BW with conditional refresh based on pagesUntilFullRefresh
     if (pagesUntilFullRefresh <= 1) {
-      renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+      renderer.displayBuffer(HalDisplay::HALF_REFRESH);
       pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
     } else {
       renderer.displayBuffer();
@@ -349,7 +349,7 @@ void XtcReaderActivity::renderPage() {
 
   // Display with appropriate refresh
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/settings/ClearCacheActivity.cpp

@@ -2,7 +2,7 @@
 
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include "MappedInputManager.h"
 #include "fontIds.h"

src/activities/util/FullScreenMessageActivity.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <EInkDisplay.h>
+#include <HalDisplay.h>
 #include <EpdFontFamily.h>
 
 #include <string>
@@ -10,12 +10,12 @@
 class FullScreenMessageActivity final : public Activity {
   std::string text;
   EpdFontFamily::Style style;
-  EInkDisplay::RefreshMode refreshMode;
+  HalDisplay::RefreshMode refreshMode;
 
  public:
   explicit FullScreenMessageActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, std::string text,
                                      const EpdFontFamily::Style style = EpdFontFamily::REGULAR,
-                                     const EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH)
+                                     const HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH)
       : Activity("FullScreenMessage", renderer, mappedInput),
         text(std::move(text)),
         style(style),

src/main.cpp

@@ -1,9 +1,9 @@
 #include <Arduino.h>
-#include <EInkDisplay.h>
+#include <HalDisplay.h>
 #include <Epub.h>
 #include <GfxRenderer.h>
-#include <InputManager.h>
+#include <HalInput.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <SPI.h>
 #include <builtinFonts/all.h>
 
@@ -39,7 +39,7 @@
 
 #define SD_SPI_MISO 7
 
-EInkDisplay einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
+HalDisplay einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
 InputManager inputManager;
 MappedInputManager mappedInputManager(inputManager);
 GfxRenderer renderer(einkDisplay);
@@ -184,12 +184,14 @@ void verifyWakeupLongPress() {
   if (abort) {
     // Button released too early. Returning to sleep.
     // IMPORTANT: Re-arm the wakeup trigger before sleeping again
-    esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+    startDeepSleep(inputManager);
-    esp_deep_sleep_start();
   }
 }
 
 void waitForPowerRelease() {
+  if (CROSSPOINT_EMULATED) {
+    return;
+  }
   inputManager.update();
   while (inputManager.isPressed(InputManager::BTN_POWER)) {
     delay(50);
@@ -205,11 +207,7 @@ void enterDeepSleep() {
   einkDisplay.deepSleep();
   Serial.printf("[%lu] [   ] Power button press calibration value: %lu ms\n", millis(), t2 - t1);
   Serial.printf("[%lu] [   ] Entering deep sleep.\n", millis());
-  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+  startDeepSleep(inputManager);
-  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
-  waitForPowerRelease();
-  // Enter Deep Sleep
-  esp_deep_sleep_start();
 }
 
 void onGoHome();
@@ -278,10 +276,13 @@ void setupDisplayAndFonts() {
 
 bool isUsbConnected() {
   // U0RXD/GPIO20 reads HIGH when USB is connected
-  return digitalRead(UART0_RXD) == HIGH;
+  return CROSSPOINT_EMULATED || digitalRead(UART0_RXD) == HIGH;
 }
 
 bool isWakeupAfterFlashing() {
+  if (CROSSPOINT_EMULATED) {
+    return true;
+  }
   const auto wakeupCause = esp_sleep_get_wakeup_cause();
   const auto resetReason = esp_reset_reason();
 

src/network/CrossPointWebServer.cpp

@@ -3,7 +3,7 @@
 #include <ArduinoJson.h>
 #include <Epub.h>
 #include <FsHelpers.h>
-#include <SDCardManager.h>
+#include <HalStorage.h>
 #include <WiFi.h>
 #include <esp_task_wdt.h>
 

src/network/HttpDownloader.h

@@ -1,5 +1,5 @@
 #pragma once
-#include <SDCardManager.h>
+#include <HalStorage.h>
 
 #include <functional>
 #include <string>