[fault] Use Build ID instead of CRC32 hash

examples/nucleo_f103rb/hard_fault/main.cpp

@@ -54,12 +54,11 @@ main()
 	if (FaultReporter::hasReport())
 	{
 		MODM_LOG_ERROR << "\n\nHardFault! Copy the data into a 'coredump.txt' file, ";
-		MODM_LOG_ERROR << "then execute 'scons postmortem firmware=";
-		MODM_LOG_ERROR << modm::hex << FaultReporter::firmware() << "'.\n\n";
-		for (const uint8_t data : FaultReporter())
-		{
+		MODM_LOG_ERROR << "then execute\n\n\tscons postmortem firmware=" << modm::hex;
+		for (const auto data : FaultReporter::buildId()) MODM_LOG_ERROR << data;
+		MODM_LOG_ERROR << "\n\n";
+		for (const auto data : FaultReporter())
 			MODM_LOG_ERROR << modm::hex << data << modm::flush;
-		}
 		MODM_LOG_ERROR << "\n\n\n" << modm::flush;
 		FaultReporter::clearAndReboot();
 	}

examples/stm32f072_discovery/hard_fault/main.cpp

@@ -40,9 +40,10 @@ main()
 	if (FaultReporter::hasReport())
 	{
 		MODM_LOG_ERROR << "\n\nHardFault! Copy the data into a 'coredump.txt' file, ";
-		MODM_LOG_ERROR << "then execute 'scons postmortem firmware=";
-		MODM_LOG_ERROR << modm::hex << FaultReporter::firmware() << "'.\n\n";
-		for (const uint8_t data : FaultReporter())
+		MODM_LOG_ERROR << "then execute\n\n\tscons postmortem firmware=" << modm::hex;
+		for (const auto data : FaultReporter::buildId()) MODM_LOG_ERROR << data;
+		MODM_LOG_ERROR << "\n\n";
+		for (const auto data : FaultReporter())
 			MODM_LOG_ERROR << modm::hex << data << modm::flush;
 		MODM_LOG_ERROR << "\n\n\n" << modm::flush;
 		FaultReporter::clearAndReboot();

examples/stm32f469_discovery/hard_fault/main.cpp

@@ -54,12 +54,11 @@ main()
 	if (FaultReporter::hasReport())
 	{
 		MODM_LOG_ERROR << "\n\nHardFault! Copy the data into a 'coredump.txt' file, ";
-		MODM_LOG_ERROR << "then execute 'scons postmortem firmware=";
-		MODM_LOG_ERROR << modm::hex << FaultReporter::firmware() << "'.\n\n";
-		for (const uint8_t data : FaultReporter())
-		{
+		MODM_LOG_ERROR << "then execute\n\n\tscons postmortem firmware=" << modm::hex;
+		for (const auto data : FaultReporter::buildId()) MODM_LOG_ERROR << data;
+		MODM_LOG_ERROR << "\n\n";
+		for (const auto data : FaultReporter())
 			MODM_LOG_ERROR << modm::hex << data << modm::flush;
-		}
 		MODM_LOG_ERROR << "\n\n\n" << modm::flush;
 		FaultReporter::clearAndReboot();
 	}

src/modm/platform/fault/crashcatcher/fault.hpp

@@ -11,6 +11,7 @@
 
 #pragma once
 #include "fault_storage.hpp"
+#include <modm/architecture/interface/build_id.hpp>
 
 /**
  * Called first after a HardFault occurred.
@@ -44,8 +45,8 @@ class FaultReporter
 
 	/// @returns report size > 0
 	static inline bool hasReport() { return begin() != end(); }
-	/// @returns a 32-bit hash of the firmware for identification
-	static inline uint32_t firmware() { return FaultStorage::firmwareHash(); }
+	/// @returns a 20-bytes SHA1 of the firmware for identification
+	static inline const std::array<uint8_t, 20>& buildId() { return modm::build_id(); }
 	/// Clears the report
 	static inline void clear() { FaultStorage::closeRead(); }
 	/// Clears the report and reboots the device

src/modm/platform/fault/crashcatcher/fault_storage.cpp

@@ -11,7 +11,6 @@
 
 #include "fault_storage.hpp"
 #include <modm/architecture/utils.hpp>
-#include <modm/math/utils/crc32.hpp>
 
 typedef struct
 {
@@ -22,8 +21,6 @@ typedef struct
 
 extern "C" const table_pool_t __table_heap_start[];
 extern "C" const table_pool_t __table_heap_end[];
-extern "C" const uint8_t __rom_start[];
-extern "C" const uint8_t __rom_end[];
 
 static constexpr uint32_t magic_start = 0xBAADC0DE;
 static constexpr uint32_t magic_end = 0xC0FFEEEE;
@@ -76,13 +73,6 @@ FaultStorage::closeRead()
 	marker_end_ptr = nullptr;
 }
 
-uint32_t
-FaultStorage::firmwareHash()
-{
-	// Compute the CRC32 of the loaded binary image
-	return modm::math::crc32(__rom_start, __rom_end - __rom_start);
-}
-
 void
 FaultStorage::openWrite()
 {

src/modm/platform/fault/crashcatcher/fault_storage.hpp

@@ -24,7 +24,6 @@ class FaultStorage
 public:
 	static size_t openRead();
 	static void closeRead();
-	static uint32_t firmwareHash();
 
 	class Iterator
 	{

src/modm/platform/fault/crashcatcher/module.lb

@@ -25,7 +25,7 @@ def prepare(module, options):
             enumeration=["core", "core+stack", "core+stack+data"],
             default="core+stack+data"))
 
-    module.depends(":crashcatcher", ":cmsis:device", ":math:utils")
+    module.depends(":crashcatcher", ":cmsis:device", ":architecture:build_id")
 
     return True
 

src/modm/platform/fault/crashcatcher/module.md

@@ -73,8 +73,9 @@ int main()
     if (FaultReporter::hasReport()) // Check first after boot
     {
         Application::partialInitialize(); // Initialize only the necessary
-        uint32_t id = FaultReporter::firmware();
-        reportBegin(id); // start your report with the firmware hash
+        reportBegin();
+        for (const uint8_t data : FaultReporter::buildId())
+            reportBuildId(data); // send each byte of Build ID
         for (const uint8_t data : FaultReporter())
             reportData(data); // send each byte of data
         reportEnd(); // end the report
@@ -108,7 +109,7 @@ int main()
         if (faultReport and applicationReady)
         {
             // Still valid AFTER clear, but BEFORE reboot
-            const uint32_t id = FaultReporter::firmware();
+            const auto id = FaultReporter::buildId();
             auto begin = FaultReporter::begin();
             auto end = FaultReporter::end();
             //
@@ -133,8 +134,17 @@ arm-none-eabi-gdb -tui executable.elf -ex "set target-charset ASCII" \
     -ex "target remote | CrashDebug --elf executable.elf --dump coredump.txt"
 ```
 
-Note that the firmware identifier is the CRC32 hash of the ROM section, this can
-help you find the right ELF file.
+Note that the `FaultReporter::buildId()` contains the GNU Build ID, which can
+help you find the right ELF file:
+
+```
+arm-none-eabi-readelf -n executable.elf
+
+Displaying notes found in: .build_id
+  Owner                 Data size Description
+  GNU                  0x00000014 NT_GNU_BUILD_ID (unique build ID bitstring)
+    Build ID: 59f08f7a37a7340799d9dba6b0c092bc3c9515c5
+```
 
 
 ### Post-Mortem Debugging with SCons
@@ -143,14 +153,14 @@ The `:build:scons` module provides a few helper methods for working with fault
 reports. You still need to copy the coredump data manually, however, the firmware
 selection is automated.
 
-The SCons build system will automatically cache both the ELF and binary files
-for the firmware ID for every firmware upload (using `scons artifact`).
-When a fault is reported, you can tell SCons the firmware hash and it will use
+The SCons build system will automatically cache the ELF file for the build id for
+every firmware upload (using `scons artifact`).
+When a fault is reported, you can tell SCons the firmware build id and it will use
 the corresponding ELF file automatically.
 
 ```sh
 # Copy data into coredump.txt
 touch coredump.txt
-# Start postmortem debugging of {hash}
-scons postmortem firmware={hash}
+# Start postmortem debugging of executable with this build id
+scons postmortem firmware=59f08f7a37a7340799d9dba6b0c092bc3c9515c5
 ```

tools/build_script_generator/scons/site_tools/artifact.py

@@ -14,23 +14,28 @@
 import shutil
 from SCons.Script import *
 import subprocess
-import binascii
+from elftools.elf.elffile import ELFFile
 
 def run_store_artifact(target, source, env):
 	artifactpath = os.path.join(env["CONFIG_BUILD_BASE"], "artifacts")
 	try:
 		os.makedirs(artifactpath)
 	except:
 		pass
-	source = str(source[0])
-	binary = os.path.splitext(source)[0]+".bin"
-	subprocess.call(env.subst("$OBJCOPY -O binary {} {}".format(source, binary)), shell=True)
-	with open(binary, "rb") as binfile:
-		firmware = binascii.crc32(binfile.read()) & 0xFFFFFFFF
-
-	artifact = os.path.join(artifactpath, "{:08X}.elf".format(firmware))
-	shutil.copy2(source, artifact)
-	shutil.copy2(binary, os.path.splitext(artifact)[0]+".bin")
+
+	with open(source[0].path, "rb") as src:
+		elffile = ELFFile(src)
+		build_id = elffile.get_section_by_name(".build_id")
+		if build_id is not None:
+			for note in build_id.iter_notes():
+				if note['n_type'] == "NT_GNU_BUILD_ID":
+					build_id = note['n_desc']
+
+	if build_id is not None:
+		artifact = os.path.join(artifactpath, "{}.elf".format(build_id.lower()))
+		shutil.copy2(source[0].path, artifact)
+	else:
+		print("Unable to find Build ID for '{}'!".format(source[0].path))
 	return 0
 
 def store_artifact(env, source, alias="store_artifact"):

tools/build_script_generator/scons/site_tools/postmortem_gdb.py

@@ -23,6 +23,7 @@ def run_post_mortem_gdb(target, source, env):
 		print("\n> Using the newest firmware may be inaccurate!\n"
 		      "> Use 'firmware={hash}' argument to specify a specific firmware.\n")
 	else:
+		artifact = artifact.lower()
 		artifactpath = os.path.join(env["CONFIG_BUILD_BASE"], "artifacts", "{}.elf".format(artifact))
 		if os.path.isfile(artifactpath):
 			source = artifactpath