buildman: make output dir configurable

Add an option to specify the output directory to override the
default path '../'. This is useful for building in a ramdisk.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/buildman.py b/tools/buildman/buildman.py
index 8822efe..73a5483 100755
--- a/tools/buildman/buildman.py
+++ b/tools/buildman/buildman.py
@@ -101,6 +101,9 @@
        default=None, help='Number of builder threads to use')
 parser.add_option('-u', '--show_unknown', action='store_true',
        default=False, help='Show boards with unknown build result')
+parser.add_option('-o', '--output-dir', type='string',
+       dest='output_dir', default='..',
+       help='Directory where all builds happen and buildman has its workspace (default is ../)')
 
 parser.usage = """buildman -b <branch> [options]
 
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index 8e6a08f..d2f4102 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -145,7 +145,7 @@
         options.step = len(series.commits) - 1
 
     # Create a new builder with the selected options
-    output_dir = os.path.join('..', options.branch)
+    output_dir = os.path.join(options.output_dir, options.branch)
     builder = Builder(toolchains, output_dir, options.git_dir,
             options.threads, options.jobs, checkout=True,
             show_unknown=options.show_unknown, step=options.step)