Merge git://git.denx.de/u-boot-dm

5 files changed, 73 insertions, 11 deletions

diff --git a/tools/buildman/README b/tools/buildman/README
index 4705d2644b..26755c5955 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -898,6 +898,48 @@ when using the -b flag. For example:
 will build commits in us-buildman that are not in upstream/master.
 
 
+Building Faster
+===============
+
+By default, buildman executes 'make mrproper' prior to building the first
+commit for each board. This causes everything to be built from scratch. If you
+trust the build system's incremental build capabilities, you can pass the -I
+flag to skip the 'make mproper' invocation, which will reduce the amount of
+work 'make' does, and hence speed up the build. This flag will speed up any
+buildman invocation, since it reduces the amount of work done on any build.
+
+One possible application of buildman is as part of a continual edit, build,
+edit, build, ... cycle; repeatedly applying buildman to the same change or
+series of changes while making small incremental modifications to the source
+each time. This provides quick feedback regarding the correctness of recent
+modifications. In this scenario, buildman's default choice of build directory
+causes more build work to be performed than strictly necessary.
+
+By default, each buildman thread uses a single directory for all builds. When a
+thread builds multiple boards, the configuration built in this directory will
+cycle through various different configurations, one per board built by the
+thread. Variations in the configuration will force a rebuild of affected source
+files when a thread switches between boards. Ideally, such buildman-induced
+rebuilds would not happen, thus allowing the build to operate as efficiently as
+the build system and source changes allow. buildman's -P flag may be used to
+enable this; -P causes each board to be built in a separate (board-specific)
+directory, thus avoiding any buildman-induced configuration changes in any
+build directory.
+
+U-Boot's build system embeds information such as a build timestamp into the
+final binary. This information varies each time U-Boot is built. This causes
+various files to be rebuilt even if no source changes are made, which in turn
+requires that the final U-Boot binary be re-linked. This unnecessary work can
+be avoided by turning off the timestamp feature. This can be achieved by
+setting the SOURCE_DATE_EPOCH environment variable to 0.
+
+Combining all of these options together yields the command-line shown below.
+This will provide the quickest possible feedback regarding the current content
+of the source tree, thus allowing rapid tested evolution of the code.
+
+    SOURCE_DATE_EPOCH=0 ./tools/buildman/buildman -I -P tegra
+
+
 Other options
 =============
 
diff --git a/tools/buildman/builder.py b/tools/buildman/builder.py
index 141bf64691..8ec3551729 100644
--- a/tools/buildman/builder.py
+++ b/tools/buildman/builder.py
@@ -205,7 +205,8 @@ class Builder:
 
     def __init__(self, toolchains, base_dir, git_dir, num_threads, num_jobs,
                  gnu_make='make', checkout=True, show_unknown=True, step=1,
-                 no_subdirs=False, full_path=False, verbose_build=False):
+                 no_subdirs=False, full_path=False, verbose_build=False,
+                 incremental=False, per_board_out_dir=False):
         """Create a new Builder object
 
         Args:
@@ -224,6 +225,10 @@ class Builder:
             full_path: Return the full path in CROSS_COMPILE and don't set
                 PATH
             verbose_build: Run build with V=1 and don't use 'make -s'
+            incremental: Always perform incremental builds; don't run make
+                mrproper when configuring
+            per_board_out_dir: Build in a separate persistent directory per
+                board rather than a thread-specific directory
         """
         self.toolchains = toolchains
         self.base_dir = base_dir
@@ -263,7 +268,8 @@ class Builder:
         self.queue = Queue.Queue()
         self.out_queue = Queue.Queue()
         for i in range(self.num_threads):
-            t = builderthread.BuilderThread(self, i)
+            t = builderthread.BuilderThread(self, i, incremental,
+                    per_board_out_dir)
             t.setDaemon(True)
             t.start()
             self.threads.append(t)
diff --git a/tools/buildman/builderthread.py b/tools/buildman/builderthread.py
index cf25bb8f1a..c512d3b521 100644
--- a/tools/buildman/builderthread.py
+++ b/tools/buildman/builderthread.py
@@ -80,11 +80,13 @@ class BuilderThread(threading.Thread):
         thread_num: Our thread number (0-n-1), used to decide on a
                 temporary directory
     """
-    def __init__(self, builder, thread_num):
+    def __init__(self, builder, thread_num, incremental, per_board_out_dir):
         """Set up a new builder thread"""
         threading.Thread.__init__(self)
         self.builder = builder
         self.thread_num = thread_num
+        self.incremental = incremental
+        self.per_board_out_dir = per_board_out_dir
 
     def Make(self, commit, brd, stage, cwd, *args, **kwargs):
         """Run 'make' on a particular commit and board.
@@ -136,7 +138,11 @@ class BuilderThread(threading.Thread):
         if self.builder.in_tree:
             out_dir = work_dir
         else:
-            out_dir = os.path.join(work_dir, 'build')
+            if self.per_board_out_dir:
+                out_rel_dir = os.path.join('..', brd.target)
+            else:
+                out_rel_dir = 'build'
+            out_dir = os.path.join(work_dir, out_rel_dir)
 
         # Check if the job was already completed last time
         done_file = self.builder.GetDoneFile(commit_upto, brd.target)
@@ -197,12 +203,12 @@ class BuilderThread(threading.Thread):
                         #
                         # Symlinks can confuse U-Boot's Makefile since
                         # we may use '..' in our path, so remove them.
-                        work_dir = os.path.realpath(work_dir)
-                        args.append('O=%s/build' % work_dir)
+                        out_dir = os.path.realpath(out_dir)
+                        args.append('O=%s' % out_dir)
                         cwd = None
                         src_dir = os.getcwd()
                     else:
-                        args.append('O=build')
+                        args.append('O=%s' % out_rel_dir)
                 if self.builder.verbose_build:
                     args.append('V=1')
                 else:
@@ -215,9 +221,11 @@ class BuilderThread(threading.Thread):
 
                 # If we need to reconfigure, do that now
                 if do_config:
-                    result = self.Make(commit, brd, 'mrproper', cwd,
-                            'mrproper', *args, env=env)
-                    config_out = result.combined
+                    config_out = ''
+                    if not self.incremental:
+                        result = self.Make(commit, brd, 'mrproper', cwd,
+                                'mrproper', *args, env=env)
+                        config_out += result.combined
                     result = self.Make(commit, brd, 'config', cwd,
                             *(args + config_args), env=env)
                     config_out += result.combined
diff --git a/tools/buildman/cmdline.py b/tools/buildman/cmdline.py
index 8341ab145c..3e3bd63e32 100644
--- a/tools/buildman/cmdline.py
+++ b/tools/buildman/cmdline.py
@@ -49,6 +49,8 @@ def ParseArgs():
     parser.add_option('-i', '--in-tree', dest='in_tree',
           action='store_true', default=False,
           help='Build in the source tree instead of a separate directory')
+    parser.add_option('-I', '--incremental', action='store_true',
+          default=False, help='Do not run make mrproper (when reconfiguring)')
     parser.add_option('-j', '--jobs', dest='jobs', type='int',
           default=None, help='Number of jobs to run at once (passed to make)')
     parser.add_option('-k', '--keep-outputs', action='store_true',
@@ -70,6 +72,8 @@ def ParseArgs():
           default=False, help='Do a rough build, with limited warning resolution')
     parser.add_option('-p', '--full-path', action='store_true',
           default=False, help="Use full toolchain path in CROSS_COMPILE")
+    parser.add_option('-P', '--per-board-out-dir', action='store_true',
+          default=False, help="Use an O= (output) directory per board rather than per thread")
     parser.add_option('-s', '--summary', action='store_true',
           default=False, help='Show a build summary')
     parser.add_option('-S', '--show-sizes', action='store_true',
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index c2c54bf0e8..aeb128a6a3 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -250,7 +250,9 @@ def DoBuildman(options, args, toolchains=None, make_func=None, boards=None,
             options.threads, options.jobs, gnu_make=gnu_make, checkout=True,
             show_unknown=options.show_unknown, step=options.step,
             no_subdirs=options.no_subdirs, full_path=options.full_path,
-            verbose_build=options.verbose_build)
+            verbose_build=options.verbose_build,
+            incremental=options.incremental,
+            per_board_out_dir=options.per_board_out_dir,)
     builder.force_config_on_failure = not options.quick
     if make_func:
         builder.do_make = make_func