ULog: add INFO_MULTIPLE & FLAG_BITS messages

This requires support in the parsers, and thus the ULog file version is
increased.
As long as no data is appended, both, existing pyulog & FlightPlot, can
still read the new logs (they will output a warning).
The replay module will print an error, but still continue.

src/modules/logger/logger.cpp

@@ -1639,10 +1639,20 @@ void Logger::write_header()
 	header.magic[4] = 0x01;
 	header.magic[5] = 0x12;
 	header.magic[6] = 0x35;
-	header.magic[7] = 0x00; //file version 0
+	header.magic[7] = 0x01; //file version 1
 	header.timestamp = hrt_absolute_time();
 	_writer.lock();
 	write_message(&header, sizeof(header));
+
+	// write the Flags message: this MUST be written right after the ulog header
+	ulog_message_flag_bits_s flag_bits;
+
+	memset(&flag_bits, 0, sizeof(flag_bits));
+	flag_bits.msg_size = sizeof(flag_bits) - ULOG_MSG_HEADER_LEN;
+	flag_bits.msg_type = static_cast<uint8_t>(ULogMessageType::FLAG_BITS);
+
+	write_message(&flag_bits, sizeof(flag_bits));
+
 	_writer.unlock();
 }
 

src/modules/logger/messages.h

@@ -37,12 +37,14 @@ enum class ULogMessageType : uint8_t {
 	FORMAT = 'F',
 	DATA = 'D',
 	INFO = 'I',
+	INFO_MULTIPLE = 'M',
 	PARAMETER = 'P',
 	ADD_LOGGED_MSG = 'A',
 	REMOVE_LOGGED_MSG = 'R',
 	SYNC = 'S',
 	DROPOUT = 'O',
 	LOGGING = 'L',
+	FLAG_BITS = 'B',
 };
 
 
@@ -113,6 +115,15 @@ struct ulog_message_info_header_s {
 	char key[255];
 };
 
+struct ulog_message_info_multiple_header_s {
+	uint16_t msg_size; //size of message - ULOG_MSG_HEADER_LEN
+	uint8_t msg_type = static_cast<uint8_t>(ULogMessageType::INFO_MULTIPLE);
+
+	uint8_t is_continued; ///< can be used for arrays: set to 1, if this message is part of the previous with the same key
+	uint8_t key_len;
+	char key[255];
+};
+
 struct ulog_message_logging_s {
 	uint16_t msg_size; //size of message - ULOG_MSG_HEADER_LEN
 	uint8_t msg_type = static_cast<uint8_t>(ULogMessageType::LOGGING);
@@ -129,4 +140,17 @@ struct ulog_message_parameter_header_s {
 	uint8_t key_len;
 	char key[255];
 };
+
+
+#define ULOG_INCOMPAT_FLAG0_DATA_APPENDED_MASK (1<<0)
+
+struct ulog_message_flag_bits_s {
+	uint16_t msg_size;
+	uint8_t msg_type = static_cast<uint8_t>(ULogMessageType::FLAG_BITS);
+
+	uint8_t compat_flags[8];
+	uint8_t incompat_flags[8]; ///< @see ULOG_INCOMPAT_FLAG_*
+	uint64_t appended_offsets[3]; ///< file offset(s) for appended data if ULOG_INCOMPAT_FLAG0_DATA_APPENDED_MASK is set
+};
+
 #pragma pack(pop)