diff --git a/app_main/src/main/java/cn/rrg/rdv/util/Paths.java b/app_main/src/main/java/cn/rrg/rdv/util/Paths.java
index 97a5bea0..706c6ab5 100644
--- a/app_main/src/main/java/cn/rrg/rdv/util/Paths.java
+++ b/app_main/src/main/java/cn/rrg/rdv/util/Paths.java
@@ -6,71 +6,73 @@ import com.termux.app.TermuxService;
 
 import java.io.File;
 
-public interface Paths {
+public class Paths {
 
-    String EXTERNAL_STORAGE_DIRECTORY = Environment.getExternalStorageDirectory().getPath();
-    String TOOLS_PATH = "NfcTools";
-    String SETTINGS_PATH = "Settings";
-    String MCT_PATH = "MifareClassicTool";
-    String MTools_PATH = "MTools";
-    String HARDNESTED_PATH = "hardnested";
-    String LOG_PATH = "log";
-    String PM3_PATH = "proxmark3";
-    String COMMON_PATH = "common";
-    String PN53X_PATH = "pn53x";
-    String DRIVER_PATH = "driver";
-    String TENCENT_PATH = "tencent";
-    String WECAT_PATH = "MicroMsg/Download";
-    String QQ_PATH = "QQfile_recv";
-    String KEY_PATH = "keyFile";
-    String DUMP_PATH = "dumpFile";
-    String DEFAULT_KEYS_NAME = "default_keys.txt";
-    String DEFAULT_DUMP_NAME = "BLANK(空白).dump";
-    String DEFAULT_CMD_NAME = "cmd.json";
+    public static String EXTERNAL_STORAGE_DIRECTORY = Environment.getExternalStorageDirectory().getPath();
+    public static String TOOLS_PATH = "NfcTools";
+    public static String SETTINGS_PATH = "Settings";
+    public static String MCT_PATH = "MifareClassicTool";
+    public static String MTools_PATH = "MTools";
+    public static String HARDNESTED_PATH = "hardnested";
+    public static String LOG_PATH = "log";
+    public static String PM3_PATH = "proxmark3";
+    public static String COMMON_PATH = "common";
+    public static String PN53X_PATH = "pn53x";
+    public static String DRIVER_PATH = "driver";
+    public static String TENCENT_PATH = "tencent";
+    public static String WECAT_PATH = "MicroMsg/Download";
+    public static String QQ_PATH = "QQfile_recv";
+    public static String KEY_PATH = "keyFile";
+    public static String DUMP_PATH = "dumpFile";
+    public static String DEFAULT_KEYS_NAME = "default_keys.txt";
+    public static String DEFAULT_DUMP_NAME = "BLANK(空白).dump";
+    public static String DEFAULT_CMD_NAME = "cmd.json";
 
-    String TOOLS_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TOOLS_PATH;
-    String KEY_DIRECTORY = TOOLS_DIRECTORY + "/" + KEY_PATH;
-    String LOG_DIRECTORY = TOOLS_DIRECTORY + "/" + LOG_PATH;
+    public static String TOOLS_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TOOLS_PATH;
+    public static String KEY_DIRECTORY = TOOLS_DIRECTORY + "/" + KEY_PATH;
+    public static String LOG_DIRECTORY = TOOLS_DIRECTORY + "/" + LOG_PATH;
 
-    String MCT_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + MCT_PATH;
-    String MCT_DUMP_DIRECTORY = MCT_DIRECTORY + "/" + "dump-files";
-    String MCT_KEYS_DIRECTORY = MCT_DIRECTORY + "/" + "key-files";
+    public static String MCT_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + MCT_PATH;
+    public static String MCT_DUMP_DIRECTORY = MCT_DIRECTORY + "/" + "dump-files";
+    public static String MCT_KEYS_DIRECTORY = MCT_DIRECTORY + "/" + "key-files";
 
-    String MTools_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + MTools_PATH;
-    String MTools_DUMP_DIRECTORY = MTools_DIRECTORY + "/" + "dump";
-    String MTools_KEYS_DIRECTORY = MTools_DIRECTORY + "/" + "key";
+    public static String MTools_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + MTools_PATH;
+    public static String MTools_DUMP_DIRECTORY = MTools_DIRECTORY + "/" + "dump";
+    public static String MTools_KEYS_DIRECTORY = MTools_DIRECTORY + "/" + "key";
 
-    String COMMON_DIRECTORY = TOOLS_DIRECTORY + "/" + COMMON_PATH;
-    String DUMP_DIRECTORY = TOOLS_DIRECTORY + "/" + DUMP_PATH;
+    public static String COMMON_DIRECTORY = TOOLS_DIRECTORY + "/" + COMMON_PATH;
+    public static String DUMP_DIRECTORY = TOOLS_DIRECTORY + "/" + DUMP_PATH;
 
-    String PM3_DIRECTORY = TOOLS_DIRECTORY + "/" + PM3_PATH;
-    String PN53X_DIRRECTORY = TOOLS_DIRECTORY + "/" + PN53X_PATH;
+    public static String PM3_DIRECTORY = TOOLS_DIRECTORY + "/" + PM3_PATH;
+    public static String PN53X_DIRRECTORY = TOOLS_DIRECTORY + "/" + PN53X_PATH;
 
-    String WECAT_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TENCENT_PATH + "/" + WECAT_PATH;
-    String QQ_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TENCENT_PATH + "/" + QQ_PATH;
+    public static String WECAT_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TENCENT_PATH + "/" + WECAT_PATH;
+    public static String QQ_DIRECTORY = EXTERNAL_STORAGE_DIRECTORY + "/" + TENCENT_PATH + "/" + QQ_PATH;
 
-    String SETTINGS_DIRECTORY = TOOLS_DIRECTORY + "/" + SETTINGS_PATH;
-    String SETTINGS_FILE = SETTINGS_DIRECTORY + "/" + "set.dat";
+    public static String SETTINGS_DIRECTORY = TOOLS_DIRECTORY + "/" + SETTINGS_PATH;
+    public static String SETTINGS_FILE = SETTINGS_DIRECTORY + "/" + "set.dat";
 
-    String PM3_BOOT_FILE_NAME = "bootrom.elf";
-    String PM3_OS_FILE_NAME = "fullimage.elf";
-    String PM3_FORWARD_O = PM3_DIRECTORY + "/" + "pm3_forward_o.txt";
-    String PM3_FORWARD_E = PM3_DIRECTORY + "/" + "pm3_forward_e.txt";
+    public static String PM3_BOOT_FILE_NAME = "bootrom.elf";
+    public static String PM3_OS_FILE_NAME = "fullimage.elf";
+    public static String PM3_FORWARD_O = PM3_DIRECTORY + "/" + "pm3_forward_o.txt";
+    public static String PM3_FORWARD_E = PM3_DIRECTORY + "/" + "pm3_forward_e.txt";
     //PM3 Easy Button
-    String PM3_CMD_FILE = PM3_DIRECTORY + "/" + DEFAULT_CMD_NAME;
+    public static String PM3_CMD_FILE = PM3_DIRECTORY + "/" + DEFAULT_CMD_NAME;
     // PM3 Image
-    String PM3_IMAGE_BOOT_FILE = TermuxService.HOME_PATH + File.separator + PM3_PATH + File.separator + PM3_BOOT_FILE_NAME;
-    String PM3_IMAGE_OS_FILE = TermuxService.HOME_PATH + File.separator + PM3_PATH + File.separator + PM3_OS_FILE_NAME;
+    public static String PM3_IMAGE_BOOT_FILE = TermuxService.HOME_PATH + File.separator + PM3_PATH + File.separator + PM3_BOOT_FILE_NAME;
+    public static String PM3_IMAGE_OS_FILE = TermuxService.HOME_PATH + File.separator + PM3_PATH + File.separator + PM3_OS_FILE_NAME;
+    // pm3 cwd -> sdcard
+    public static String PM3_CWD = PM3_DIRECTORY + File.separator + "home";
 
-    String PN53X_FORWARD_O = PN53X_DIRRECTORY + "/" + "pn53x_forward_o.txt";
-    String PN53X_FORWARD_E = PN53X_DIRRECTORY + "/" + "pn53x_forward_e.txt";
-    String PN53X_FORWARD_MF_O = PN53X_DIRRECTORY + "/" + "pn53x_forward_mf_o.txt";
-    String PN53X_FORWARD_MF_E = PN53X_DIRRECTORY + "/" + "pn53x_forward_mf_e.txt";
-    String COMMON_FORWARD_O = COMMON_DIRECTORY + "/" + "common_forward_o.txt";
-    String COMMON_FORWARD_E = COMMON_DIRECTORY + "/" + "common_forward_e.txt";
-    String COMMON_FORWARD_I = COMMON_DIRECTORY + "/" + "common_forward_i.txt";
+    public static String PN53X_FORWARD_O = PN53X_DIRRECTORY + "/" + "pn53x_forward_o.txt";
+    public static String PN53X_FORWARD_E = PN53X_DIRRECTORY + "/" + "pn53x_forward_e.txt";
+    public static String PN53X_FORWARD_MF_O = PN53X_DIRRECTORY + "/" + "pn53x_forward_mf_o.txt";
+    public static String PN53X_FORWARD_MF_E = PN53X_DIRRECTORY + "/" + "pn53x_forward_mf_e.txt";
+    public static String COMMON_FORWARD_O = COMMON_DIRECTORY + "/" + "common_forward_o.txt";
+    public static String COMMON_FORWARD_E = COMMON_DIRECTORY + "/" + "common_forward_e.txt";
+    public static String COMMON_FORWARD_I = COMMON_DIRECTORY + "/" + "common_forward_i.txt";
 
-    String DEFAULT_KEYS_FILE = KEY_DIRECTORY + "/" + DEFAULT_KEYS_NAME;
-    String DEFAULT_DUMP_FILE = DUMP_DIRECTORY + "/" + DEFAULT_DUMP_NAME;
-    String DRIVER_DIRECTORY = TOOLS_DIRECTORY + "/" + DRIVER_PATH;
+    public static String DEFAULT_KEYS_FILE = KEY_DIRECTORY + "/" + DEFAULT_KEYS_NAME;
+    public static String DEFAULT_DUMP_FILE = DUMP_DIRECTORY + "/" + DEFAULT_DUMP_NAME;
+    public static String DRIVER_DIRECTORY = TOOLS_DIRECTORY + "/" + DRIVER_PATH;
 }