west: sign/rimage: use rimage config to find SOF directory

boards/intel/adsp/doc/intel_adsp_generic.rst

@@ -60,22 +60,26 @@ Signing Tool
 As firmware binary signing is mandatory on Intel products from Skylake onwards,
 you will also need to set up the SOF rimage signing tool and key.
 
-.. code-block:: shell
-
-   cd zephyrproject
-   west config manifest.project-filter -- +sof
-   west update
-   cd modules/audio/sof/tools/rimage
+Clone the SOF repository and follow the instructions in the rimage :file:`README.md`
+to build the tool on your system.
 
-Follow the instructions in the rimage :file:`README.md` to build the tool on
-your system. You can either copy the executable to a directory in your PATH or
+You can either copy the executable to a directory in your PATH or
 use ``west config rimage.path /path/to/rimage-build/rimage``; see more details
 in the output of ``west sign -h``. Running directly from the build directory
 makes you less likely to use an obsolete rimage version by mistake.
 
-Platform-specific configuration files are located in the ``rimage/config/``
-subdirectory. For a different configuration directory you can use:
-``west config build.cmake-args -- -DRIMAGE_CONFIG_PATH=/path/to/my/rimage/config``.
+The west signing script will also need to know the path to the SOF directory.
+Depending on whether you need to use twister:
+
+* If you only need to build with ``west build``:
+
+  * Platform-specific configuration files are located in the ``rimage/config/``
+    subdirectory. For a different configuration directory you can use:
+    ``west config build.cmake-args -- -DRIMAGE_CONFIG_PATH=/path/to/my/rimage/config``.
+
+* If you also need to use twister to build and run on hardware:
+
+  * Environment variable ``SOF_SRC_DIR`` must be set to point to the SOF directory.
 
 
 Xtensa Toolchain (Optional)

scripts/west_commands/sign.py

@@ -423,6 +423,75 @@ def edt_flash_params(cmd, flash):
 
 class RimageSigner(Signer):
 
+    def check_if_sof_dir(self, maybe_sof_dir):
+        '''
+        Check if a pathlib.Path() object is the root of the SOF tree.
+
+        Returns a Path object if it is indeed the SOF tree, or None if not.
+
+        This checks if the file "versions.json" exists under the path, as
+        this file contains the SOF versioning information.
+        '''
+        versions_json_file = maybe_sof_dir / 'versions.json'
+        if versions_json_file.exists():
+            return maybe_sof_dir
+
+        return None
+
+    def get_sof_src_dir(self):
+        '''
+        Find the SOF tree.
+
+        Returns a Path object if SOF tree is found, or None if not.
+        '''
+        sof_src_dir = None
+
+        # Try to find SOF directory via path to rimage config files pointed to
+        # via CMake cached variable "RIMAGE_CONFIG_PATH" if it exists.
+        # The config files are inside <sof top>/tools/tools/rimage/config in
+        # the SOF tree.
+        conf_dir = self.cmake_cache.get('RIMAGE_CONFIG_PATH')
+        if conf_dir:
+            # Config path is <sof top>/tools/rimage/config/
+            # So need to go up 3 levels to get SOF directory.
+            maybe_sof_dir = pathlib.Path(conf_dir).parent.parent.parent
+
+            # Make sure this is the actual SOF directory as
+            # RIMAGE_CONFIG_PATH may point to somewhere else.
+            sof_src_dir = self.check_if_sof_dir(maybe_sof_dir)
+
+        # Try to find SOF if it is included via manifest as a project
+        # under the main manifest (e.g. included via a sub-manifest).
+        if not sof_src_dir:
+            try:
+                sof_proj = self.command.manifest.get_projects(['sof'], allow_paths=False)
+                sof_src_dir = pathlib.Path(sof_proj[0].abspath)
+
+                # Since SOF is pulled in as a project, we assume it is
+                # the correct one as the manifest has to be modified
+                # manually.
+            except ValueError:
+                pass
+
+        # Try to find SOF as SOF is the top level manifest via west init.
+        if not sof_src_dir:
+            maybe_sof_dir = pathlib.Path(manifest.manifest_path()).parent
+
+            # Make sure this is the actual SOF directory
+            # as the top level manifest may not be SOF.
+            sof_src_dir = self.check_if_sof_dir(maybe_sof_dir)
+
+        # If the above all failed to find the SOF tree, see if the path is specified
+        # via environment variable "SOF_SRC_DIR" as last resort.
+        if not sof_src_dir and os.getenv("SOF_SRC_DIR"):
+            maybe_sof_dir = pathlib.Path(os.getenv("SOF_SRC_DIR"))
+
+            # Make sure this is the actual SOF directory
+            # as the top level manifest may not be SOF.
+            sof_src_dir = self.check_if_sof_dir(maybe_sof_dir)
+
+        return sof_src_dir
+
     def rimage_config_dir(self):
         'Returns the rimage/config/ directory with the highest precedence'
         args = self.command.args
@@ -438,7 +507,11 @@ def rimage_config_dir(self):
     def generate_uuid_registry(self):
         'Runs the uuid-registry.h generator script'
 
-        generate_cmd = [sys.executable, str(self.sof_src_dir / 'scripts' / 'gen-uuid-reg.py'),
+        uuid_script_path = self.sof_src_dir / 'scripts' / 'gen-uuid-reg.py'
+        if not uuid_script_path.exists():
+            self.command.die(f"{uuid_script_path} does not exists.")
+
+        generate_cmd = [sys.executable, str(uuid_script_path),
                         str(self.sof_src_dir / 'uuid-registry.txt'),
                         str(pathlib.Path('zephyr') / 'include' / 'generated' / 'uuid-registry.h')
                        ]
@@ -554,13 +627,11 @@ def sign(self, command, build_dir, build_conf, formats):
         if not args.quiet:
             command.inf('Signing with tool {}'.format(tool_path))
 
-        try:
-            sof_proj = command.manifest.get_projects(['sof'], allow_paths=False)
-            sof_src_dir = pathlib.Path(sof_proj[0].abspath)
-        except ValueError: # sof is the manifest
-            sof_src_dir = pathlib.Path(manifest.manifest_path()).parent
-
-        self.sof_src_dir = sof_src_dir
+        self.sof_src_dir = self.get_sof_src_dir()
+        if self.sof_src_dir:
+            command.inf(f"SOF directory: {self.sof_src_dir}")
+        else:
+            command.die("Cannot find SOF directory.")
 
 
         command.inf('Signing for SOC target ' + target)
@@ -605,7 +676,7 @@ def sign(self, command, build_dir, build_conf, formats):
         if '-k' not in sign_config_extra_args + args.tool_args:
             # rimage requires a key argument even when it does not sign
             cmake_default_key = cache.get('RIMAGE_SIGN_KEY', 'key placeholder from sign.py')
-            extra_ri_args += [ '-k', str(sof_src_dir / 'keys' / cmake_default_key) ]
+            extra_ri_args += [ '-k', str(self.sof_src_dir / 'keys' / cmake_default_key) ]
 
         if args.tool_data and '-c' in args.tool_args:
             command.wrn('--tool-data ' + args.tool_data + ' ignored! Overridden by: -- -c ... ')