[U-Boot] [RFC PATCH] tools/buildman: Add env-flags section support

[Tom Rini]

In some cases (such as building little endian MIPS with the ELDK
toolchain) you need to set a variable in the environment in order for
the build to complete.  Add env-flags, similar to make-flags, to allow
for this.

Signed-off-by: Tom Rini <trini at ti.com>
---

I have this as RFC since GetEnvSettings is a copy/paste of
GetMakeArguments and that tells me there must be a pythonic way of
extending / renaming GetMakeArguments to take the dict to work from as
an argument.  And as per my other email, ${variable-board} doesn't work
so the README is actually incorrect.

 tools/buildman/README           |   24 +++++++++++++++++++++++
 tools/buildman/builderthread.py |    6 ++++++
 tools/buildman/toolchain.py     |   40 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+)

diff --git a/tools/buildman/README b/tools/buildman/README
index d4e8404..b513b81 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -676,6 +676,30 @@ It is expected that any variables added are dealt with in U-Boot's
 config.mk file and documented in the README.
 
 
+Providing key/value pairs to the environment
+============================================
+
+U-Boot's build system supports a few environment variables (such as
+CONFIG_USE_PRIVATE_LIBGCC) which affect the build product. These flags can be
+specified in the buildman settings file. They can also be useful when building
+U-Boot against other open source software.
+
+[env-flags]
+mipsel-flags=CONFIG_USE_PRIVATE_LIBGCC=y
+qemu_mipsel=${mipsel-flags}
+maltael=${mipsel-flags}
+pb1000=${mipsel-flags}
+dbau1550_el=${mipsel-flags}
+
+This will set 'CONFIG_USE_PRIVATE_LIBGCC' to 'y' in the environment for
+qemu_mipsel, maltael, pb100 and dbau1550_el.  A special variable ${target} is
+available to access the target name (qemu_mipsel, maltael, pb1000 and
+dbau1550_el in this case). Variables are resolved recursively.
+
+It is expected that any variables added are dealt with in U-Boot's
+config.mk file and documented in the README.
+
+
 Quick Sanity Check
 ==================
 
diff --git a/tools/buildman/builderthread.py b/tools/buildman/builderthread.py
index 8214662..920752c 100644
--- a/tools/buildman/builderthread.py
+++ b/tools/buildman/builderthread.py
@@ -174,6 +174,12 @@ class BuilderThread(threading.Thread):
 
                 # Set up the environment and command line
                 env = self.toolchain.MakeEnvironment()
+
+                # Add additional flags
+                for flag in self.builder.toolchains.GetEnvSettings(brd):
+                    key_val = flag.split('=')
+                    env[key_val[0]] = key_val[1]
+
                 Mkdir(out_dir)
                 args = []
                 cwd = work_dir
diff --git a/tools/buildman/toolchain.py b/tools/buildman/toolchain.py
index 1b9771f..1ab59b3 100644
--- a/tools/buildman/toolchain.py
+++ b/tools/buildman/toolchain.py
@@ -111,6 +111,7 @@ class Toolchains:
             else:
                 self.paths.append(value)
         self._make_flags = dict(bsettings.GetItems('make-flags'))
+        self._env_flags = dict(bsettings.GetItems('env-flags'))
 
     def Add(self, fname, test=True, verbose=False):
         """Add a toolchain to our list
@@ -245,3 +246,42 @@ class Toolchains:
             else:
                 i += 1
         return args
+
+    def GetEnvSettings(self, board):
+        """Returns key=value pairs to set in the environment prior to 'make'
+
+        The flags are in a section called 'env-flags'. Flags are named
+        after the target they represent, for example snapper9260=TESTING=1
+        will set TESTING to 1 in the environment prior to invoking make when
+        building the snapper9260 board.
+
+        References to other boards can be added in the string also. For
+        example:
+
+        [env-flags]
+        at91-boards=ENABLE_AT91_TEST=1
+        snapper9260=${at91-boards} BUILD_TAG=442
+        snapper9g45=${at91-boards} BUILD_TAG=443
+
+        This will return 'ENABLE_AT91_TEST=1 BUILD_TAG=442' for snapper9260
+        and 'ENABLE_AT91_TEST=1 BUILD_TAG=443' for snapper9g45.
+
+        A special 'target' variable is set to the board target.
+
+        Args:
+            board: Board object for the board to check.
+        Returns:
+            key=value parts to set in the environment for that board, or ''
+            if none
+        """
+        self._env_flags['target'] = board.target
+        arg_str = self.ResolveReferences(self._env_flags,
+                           self._env_flags.get(board.target, ''))
+        args = arg_str.split(' ')
+        i = 0
+        while i < len(args):
+            if not args[i]:
+                del args[i]
+            else:
+                i += 1
+        return args
-- 
1.7.9.5