Update README.md

Author: vChavezB

README.md

@@ -20,12 +20,16 @@ Refer to the examples folder to check how you could integrate lwIP with a MAC-PH
 
 ## Debug
 
-Debug options can be changed directly from the macros located in `src/lwip_debug_opt.h`.
+- Debug options can be changed directly from the macros located in `src/lwip_debug_opt.h`.
+- Debug messages are sent via `Serial` object. `Serial` must be initialized (i.e. `Serial.begin`)
 
+## LwIP Options
+
+Options are located in src/lwipopts.h
 
 ## Notes
 
-- Currently the port is intended to work with bare metal systems. I.e., the [OS Layer](https://www.nongnu.org/lwip/2_0_x/group__sys__os.html) is not implemented. The reason is that Arduino does not have an OS abstraction layer.
+- Currently the port is intended to work with bare metal systems. I.e., the [OS Layer](https://www.nongnu.org/lwip/2_0_x/group__sys__os.html) is not implemented. The reason is that Arduino does not have an OS abstraction layer and porting to a specific RTOs (ucos, VxWorks, FreeRTOS,etc) would make the library tightly coupled.
 - Not compatible with ESP32 core, as ESP32 already includes lwIP and will create conflicts with the headers of this library.
 - Will probably not fit in small MCUs, use something with much more SRAM and Flash such as the Arduino Due, RPI Pico.