[core] Add GNU Build ID as firmware identifier

src/modm/architecture/interface/build_id.hpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2019, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <cstdint>
+#include <array>
+
+namespace modm
+{
+
+/**
+ * Return the GNU Build ID as a 160-bit SHA1 array.
+ *
+ * @ingroup modm_architecture_build_id
+ */
+[[nodiscard]]
+const std::array<uint8_t, 20>&
+build_id();
+
+}

src/modm/architecture/module.lb

@@ -88,6 +88,19 @@ class BlockDevice(Module):
         env.copy("interface/block_device.hpp")
 # -----------------------------------------------------------------------------
 
+class BuildId(Module):
+    def init(self, module):
+        module.name = "build_id"
+        module.description = "GNU Build ID"
+
+    def prepare(self, module, options):
+        return True
+
+    def build(self, env):
+        env.outbasepath = "modm/src/modm/architecture"
+        env.copy("interface/build_id.hpp")
+# -----------------------------------------------------------------------------
+
 class Can(Module):
     def init(self, module):
         module.name = "can"
@@ -348,6 +361,7 @@ def prepare(module, options):
     module.add_submodule(Assert())
     module.add_submodule(Atomic())
     module.add_submodule(BlockDevice())
+    module.add_submodule(BuildId())
     module.add_submodule(Can())
     module.add_submodule(Clock())
     module.add_submodule(Delay())

src/modm/platform/core/cortex/build_id.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#include <modm/architecture/interface/build_id.hpp>
+
+typedef struct {
+    uint32_t namesz;
+    uint32_t descsz;
+    uint32_t type;
+    uint8_t data[];
+} ElfNoteSection_t;
+extern "C" const ElfNoteSection_t __build_id[];
+
+namespace modm
+{
+
+const std::array<uint8_t, 20>&
+build_id()
+{
+	const uint8_t *const sha1 = &__build_id->data[__build_id->namesz];
+	auto *const hash = reinterpret_cast<const std::array<uint8_t, 20> *>(sha1);
+	return *hash;
+}
+
+}

src/modm/platform/core/cortex/linker.macros

@@ -287,6 +287,12 @@ TOTAL_STACK_SIZE = MAIN_STACK_SIZE + PROCESS_STACK_SIZE;
 		KEEP(*(.assertion))
 		__assertion_table_end = .;
 	} >{{memory}}
+
+	.build_id :
+	{
+		__build_id = .;
+		KEEP(*(.note.gnu.build-id))
+	} > {{memory}}
 %% endmacro
 
 

src/modm/platform/core/cortex/module.lb

@@ -152,6 +152,7 @@ def prepare(module, options):
         ":architecture:interrupt",
         ":architecture:memory",
         ":architecture:unaligned",
+        ":architecture:build_id",
         ":platform:clock",
         ":cmsis:device")
 
@@ -274,6 +275,9 @@ def build(env):
     env.template("delay.cpp.in")
     env.copy("delay.hpp")
 
+    # GNU Build ID
+    env.copy("build_id.cpp")
+
     # modm-test implements the clock methods itself
     if not env.has_module(":test:architecture"):
         env.copy("clock.cpp")

tools/build_script_generator/common.py

@@ -203,7 +203,8 @@ def common_compiler_flags(compiler, target):
             "-Wl,--fatal-warnings",
             "-Wl,--gc-sections",
             "-Wl,--relax",
-            "-Wl,-Map,{target_base}.map,--cref",
+            "-Wl,--build-id=sha1",
+            # "-Wl,-Map,{target_base}.map,--cref",
         ]
     # C Preprocessor defines
     flags["cppdefines"] = []