feat: add 'vol' command

kernel/src/Fs/Vfs.cpp

@@ -350,10 +350,10 @@ namespace Fs::Vfs {
         vfsLock.Release();
         return count;
     }
-
-    int VfsDriveLabel(int driveNumber, char* outLabel, int maxLen) {
-        if (outLabel == nullptr || maxLen <= 0) return -1;
-        outLabel[0] = '\0';
+    static int CopyDriveString(int driveNumber, const char* (*FsDriver::*hook)(void*),
+                               char* out, int maxLen) {
+        if (out == nullptr || maxLen <= 0) return -1;
+        out[0] = '\0';
 
         vfsLock.Acquire();
         FsDriver* driver = DriverForLocked(driveNumber);
@@ -362,28 +362,36 @@ namespace Fs::Vfs {
             return -1;
         }
 
-        if (driver->GetLabel == nullptr) {
+        if (driver->*hook == nullptr) {
             vfsLock.Release();
             return 0;
         }
 
-        const char* label = driver->GetLabel(driver->ctx);
-        if (label == nullptr || label[0] == '\0') {
+        const char* value = (driver->*hook)(driver->ctx);
+        if (value == nullptr || value[0] == '\0') {
             vfsLock.Release();
             return 0;
         }
 
         int copied = 0;
-        while (label[copied] != '\0' && copied < maxLen - 1) {
-            outLabel[copied] = label[copied];
+        while (value[copied] != '\0' && copied < maxLen - 1) {
+            out[copied] = value[copied];
             copied++;
         }
-        outLabel[copied] = '\0';
+        out[copied] = '\0';
 
         vfsLock.Release();
         return copied;
     }
 
+    int VfsDriveLabel(int driveNumber, char* outLabel, int maxLen) {
+        return CopyDriveString(driveNumber, &FsDriver::GetLabel, outLabel, maxLen);
+    }
+
+    int VfsDriveFsType(int driveNumber, char* outType, int maxLen) {
+        return CopyDriveString(driveNumber, &FsDriver::GetFsType, outType, maxLen);
+    }
+
     int VfsRename(const char* oldPath, const char* newPath) {
         int oldDrive, newDrive;
         const char* oldLocal;