board_identity:Add stm32 board_get_px4_guid and board_get_px4_guid_formated API

src/drivers/boards/common/stm32/board_identity.c

@@ -44,6 +44,8 @@
 #define CPU_UUID_BYTE_FORMAT_ORDER          {3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8}
 #define SWAP_UINT32(x) (((x) >> 24) | (((x) & 0x00ff0000) >> 8) | (((x) & 0x0000ff00) << 8) | ((x) << 24))
 
+static const uint16_t soc_arch_id = PX4_SOC_ARCH_ID;
+
 /* A type suitable for holding the reordering array for the byte format of the UUID
  */
 
@@ -124,3 +126,42 @@ int board_get_mfguid_formated(char *format_buffer, int size)
 
 	return offset;
 }
+
+int board_get_px4_guid(px4_guid_t px4_guid)
+{
+	uint8_t  *pb = (uint8_t *) &px4_guid[0];
+	*pb++ = (soc_arch_id >> 8) & 0xff;
+	*pb++ = (soc_arch_id & 0xff);
+
+	for (unsigned i = 0; i < PX4_GUID_BYTE_LENGTH - (sizeof(soc_arch_id) + PX4_CPU_UUID_BYTE_LENGTH); i++) {
+		*pb++ = 0;
+	}
+
+	uint32_t  *rv = (uint32_t *) pb;
+	uint32_t *chip_uuid = (uint32_t *) STM32_SYSMEM_UID;
+
+	for (unsigned i = 0; i < PX4_CPU_UUID_WORD32_LENGTH; i++) {
+		*rv++ = SWAP_UINT32(chip_uuid[(PX4_CPU_UUID_WORD32_LENGTH - 1) - i]);
+	}
+
+	return PX4_GUID_BYTE_LENGTH;
+}
+
+int board_get_px4_guid_formated(char *format_buffer, int size)
+{
+	px4_guid_t px4_guid;
+	board_get_px4_guid(px4_guid);
+	int offset  = 0;
+
+	/* size should be 2 per byte + 1 for termination
+	 * So it needs to be odd
+	 */
+	size = size & 1 ? size : size - 1;
+
+	/* Discard from MSD */
+	for (unsigned i = PX4_GUID_BYTE_LENGTH - size / 2; offset < size && i < PX4_GUID_BYTE_LENGTH; i++) {
+		offset += snprintf(&format_buffer[offset], size - offset, "%02x", px4_guid[i]);
+	}
+
+	return offset;
+}