diff --git a/firmware/console/console_io.cpp b/firmware/console/console_io.cpp
index 2ebf9d9f04..9f616045a6 100644
--- a/firmware/console/console_io.cpp
+++ b/firmware/console/console_io.cpp
@@ -6,6 +6,22 @@
  *
  * This file is part of rusEfi - see http://rusefi.com
  *
+ * rusEFI can communicate with external universe via native USB or some sort of TTL mode
+ * We have an interesting situation with TTL communication channels, we have
+ * 1) SERIAL - this one was implemented first simply because the code was readily available (works on stm32)
+ *    this one is most suitable for streaming HAL API
+ *    this one is not great since each byte requires an IRQ and with enough IRQ delay we have a risk of data loss
+ * 2) UART DMA - the best one since FIFO buffer reduces data loss (works on stm32)
+ *    We have two halves of DMA buffer - one is used for TTL while rusEFI prepares next batch of data in the other side.
+ *    We need idle support in order to not wait for the complete buffer to get full in order to recieve a message.
+ *    Back when we were implementing this STM32_DMA_CR_HTIE was not available in ChibiOS driver so we have added it.
+ *    we have custom rusEFI changes to ChibiOS HAL driver v1
+ *    F7 uses driver v2 which currently does not have rusEFI changes.
+ *    open question if fresh ChibiOS is better in this regard.
+ * 3) UART this one is useful on platforms with hardware FIFO buffer like Kinetis.
+ *    stm32 does not have such buffer so for stm32 UART without DMA has no advantages
+ *
+ *
  * rusEfi is free software; you can redistribute it and/or modify it under the terms of
  * the GNU General Public License as published by the Free Software Foundation; either
  * version 3 of the License, or (at your option) any later version.