!70 hb build单独编译单板，不需要hb set

Merge pull request !70 from SimonLi/master

.gitignore

 __pycache__/
 *.py[cod]
-.vscode
\ No newline at end of file
+.vscode
+*.swp
+cscope.*
+tags

hb/build/build_process.py

@@ -186,6 +186,8 @@ class Build():
         if self._target is None and Device.is_in_device():
             # Compile device board
             device_path, kernel, board = Device.device_menuconfig()
+            # xxx: build device, no need to set root manually, so set it speculatively.
+            self.config.root_path = os.path.dirname(os.path.dirname(os.path.dirname(os.getcwd())))
             self.config.out_path = os.path.join(self.config.root_path,
                                                 'out',
                                                 board)

hb/common/device.py

@@ -18,7 +18,6 @@
 import os
 import re
 
-from hb.common.config import Config
 from hb.cts.menuconfig import Menuconfig
 
 
@@ -26,8 +25,7 @@ class Device():
     @staticmethod
     def is_in_device():
         cwd_pardir = os.path.dirname(os.path.dirname(os.getcwd()))
-        config = Config()
-        return os.path.join(config.root_path, 'device') == cwd_pardir
+        return os.path.basename(cwd_pardir) == 'device'
 
     @staticmethod
     def is_kernel(kernel_path):