m5: clean before build to not break across archs

build-buildroot: fix exception...

README.adoc

@@ -2179,6 +2179,10 @@ We used to "support" it until f8c0502bb2680f2dbe7c1f3d7958f60265347005 (it boote
 
 If you want to revive and maintain it, send a pull request.
 
+=== Other architectures
+
+It should not be too hard to port this repository to any architecture that Buildroot supports. Pull requests are welcome.
+
 == init
 
 When the Linux kernel finishes booting, it runs an executable as the first and only userland process. This executable is called the `init` program.

build-buildroot

@@ -107,7 +107,7 @@ usually extra Buildroot targets.
                 'BR2_PACKAGE_OVERRIDE_FILE="{}"'.format(
                     self._path_relative_to_buildroot(os.path.join(common.root_dir, 'buildroot_override'))
                 ),
-                'BR2_ROOTFS_OVERLAY="{} {}"'.format(
+                'BR2_ROOTFS_OVERLAY="{}"'.format(
                     self._path_relative_to_buildroot(common.out_rootfs_overlay_dir),
                 ),
                 'BR2_ROOTFS_POST_BUILD_SCRIPT="{}"'.format(

build-m5

@@ -24,11 +24,13 @@ class M5Component(common.Component):
 
     def do_build(self, args):
         os.makedirs(common.gem5_m5_build_dir, exist_ok=True)
+        # We must clean first or else the build outputs of one arch can conflict with the other.
+        # I should stop being lazy and go actually patch gem5 to support out of tree m5 build...
+        self.clean(args)
         common.run_cmd(
             self.get_make_cmd(args),
             cwd=common.gem5_m5_src_dir,
         )
-        print(common.out_rootfs_overlay_bin_dir)
         os.makedirs(common.out_rootfs_overlay_bin_dir, exist_ok=True)
         common.cp(os.path.join(common.gem5_m5_src_dir, 'm5'), common.out_rootfs_overlay_bin_dir)