mavlink: implement COMPONENT_INFORMATION

- implement COMP_METADATA_TYPE_VERSION & add component_version.json.gz to
  ROMFS for all targets.
- implement COMP_METADATA_TYPE_PARAMETER (only enabled for SITL currently)

src/lib/component_information/CMakeLists.txt

@@ -0,0 +1,70 @@
+############################################################################
+#
+#   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+set(component_version_extra_args)
+# We disable parameter support if the metadata is not in the ROMFS. This can be
+# removed once it is stored on a server
+list(FIND config_romfs_extra_dependencies "parameters_xml" index)
+if (${index} EQUAL -1)
+	set(component_version_extra_args "--no-parameters")
+endif()
+
+set(component_version_json ${PX4_BINARY_DIR}/component_version.json)
+add_custom_command(OUTPUT ${component_version_json} ${component_version_json}.gz
+	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/generate_component_version.py
+		${component_version_json}
+		--compress
+		${component_version_extra_args}
+	DEPENDS
+		generate_component_version.py
+	COMMENT "Generating component_version.json"
+)
+add_custom_target(component_version_json DEPENDS ${component_version_json})
+
+
+set(component_information_header ${CMAKE_CURRENT_BINARY_DIR}/hashes.h)
+add_custom_command(OUTPUT ${component_information_header}
+	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/generate_hashes.py
+		${PX4_BINARY_DIR}/params.json.gz
+		${component_version_json}
+		--output ${component_information_header}
+	DEPENDS
+		generate_hashes.py
+		parameters_xml
+		${PX4_BINARY_DIR}/params.json.gz
+		${component_version_json}
+	COMMENT "Generating component_information/hashes.h"
+)
+add_custom_target(component_information_header DEPENDS ${component_information_header})
+
+

src/lib/component_information/generate_component_version.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+import argparse
+import json
+import gzip
+
+parser = argparse.ArgumentParser(description="""Generate the COMPONENT_VERSION json file""")
+parser.add_argument('filename', metavar='component_version.json', help='JSON output file')
+parser.add_argument('--compress', action='store_true', help='Add a compressed output file')
+parser.add_argument('--no-parameters', action='store_true', help='disable parameter support')
+
+args = parser.parse_args()
+filename = args.filename
+compress = args.compress
+
+def save_compressed(filename):
+    #create gz compressed version
+    gz_filename=filename+'.gz'
+    with gzip.open(gz_filename, 'wt') as f:
+        with open(filename, 'r') as content_file:
+            f.write(content_file.read())
+
+component_version = {}
+component_version['version'] = 1
+# types:
+# 0: COMP_METADATA_TYPE_VERSION
+# 1: COMP_METADATA_TYPE_PARAMETER
+# 2: COMP_METADATA_TYPE_COMMANDS
+supported_types = [0]
+if not args.no_parameters: supported_types.append(1)
+component_version['supportedCompMetadataTypes'] = supported_types
+
+with open(filename, 'w') as outfile:
+    json.dump(component_version, outfile)
+
+if compress:
+    save_compressed(filename)

src/lib/component_information/generate_hashes.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python
+
+import argparse
+import zlib
+import os
+
+parser = argparse.ArgumentParser(description="""Generate the COMPONENT_INFORMATION hashes header file""")
+parser.add_argument('--output', metavar='hashes.h', help='output file')
+parser.add_argument('files', nargs='+', metavar='hashes.json', help='files to generate hashes from')
+
+args = parser.parse_args()
+filename = args.output
+files = args.files
+
+with open(filename, 'w') as outfile:
+    outfile.write("#include <stdint.h>\n")
+    outfile.write("namespace component_information {\n")
+    for filename in files:
+        # get CRC
+        file_hash = 0
+        for line in open(filename, "rb"):
+            file_hash = zlib.crc32(line, file_hash)
+
+        basename = os.path.basename(filename)
+        identifier = basename.split('.')[0]
+        outfile.write("static constexpr uint32_t {:}_hash = {:};\n".format(identifier, file_hash))
+
+
+    outfile.write("}\n")
+
+