创建，添加sdram

rt-thread/components/dfs/dfs_v2/SConscript

@@ -0,0 +1,22 @@
+from building import *
+import os
+
+# The set of source files associated with this SConscript file.
+src = Glob('src/*.c') + Glob('src/*.cpp')
+cwd = GetCurrentDir()
+CPPPATH = [cwd + "/include"]
+
+if not GetDepend('RT_USING_SMART'):
+    SrcRemove(src, ['src/dfs_file_mmap.c'])
+
+group = DefineGroup('Filesystem', src, depend = ['RT_USING_DFS', 'RT_USING_DFS_V2'], CPPPATH = CPPPATH)
+
+if GetDepend('RT_USING_DFS') and GetDepend('RT_USING_DFS_V2'):
+    # search in the file system implementation
+    list = os.listdir(cwd)
+
+    for item in list:
+        if os.path.isfile(os.path.join(cwd, item, 'SConscript')):
+            group = group + SConscript(os.path.join(item, 'SConscript'))
+
+Return('group')