diff --git a/cores/arduino/Arduino.h b/cores/arduino/Arduino.h
index 013e5a61..54e31813 100644
--- a/cores/arduino/Arduino.h
+++ b/cores/arduino/Arduino.h
@@ -30,13 +30,6 @@ typedef bool boolean;
 typedef uint8_t byte;
 typedef uint16_t word;
 
-// some libraries and sketches depend on this AVR stuff,
-// assuming Arduino.h or WProgram.h automatically includes it...
-//
-#include "avr/pgmspace.h"
-#include "avr/interrupt.h"
-#include "avr/io.h"
-
 #include "binary.h"
 #include "itoa.h"
 
@@ -89,6 +82,12 @@ void loop( void ) ;
 // Include board variant
 #include "variant.h"
 
+// some libraries and sketches depend on this AVR stuff,
+// assuming Arduino.h or WProgram.h automatically includes it...
+#include "avr/pgmspace.h"
+#include "avr/interrupt.h"
+#include "avr/io.h"
+
 #include "wiring.h"
 #include "wiring_digital.h"
 #include "wiring_analog.h"
diff --git a/cores/arduino/avr/io.h b/cores/arduino/avr/io.h
index 01982e0b..5793ede4 100644
--- a/cores/arduino/avr/io.h
+++ b/cores/arduino/avr/io.h
@@ -25,10 +25,27 @@
 #ifndef _IO_H_
 #define _IO_H_
 
-#define RAMSTART 0x20000000
-#define RAMSIZE  (20 * 1024)
+#include <Arduino.h>
+#include <assert.h>
+
+#define RAMSTART (SRAM_BASE)
+#define RAMSIZE  (SRAM_SIZE_MAX)
 #define RAMEND   (RAMSTART + RAMSIZE - 1)
 
-#define E2END    0xfff
+#if defined(DATA_EEPROM_BASE) && defined(DATA_EEPROM_END)
+  #define REAL_E2END (DATA_EEPROM_END - DATA_EEPROM_BASE)
+#elif defined(DATA_EEPROM_BASE) && defined(DATA_EEPROM_BANK2_BASE) && defined(DATA_EEPROM_BANK1_END) && defined(DATA_EEPROM_BANK2_END)
+  #define REAL_E2END (DATA_EEPROM_BANK1_END - DATA_EEPROM_BASE + 1 + DATA_EEPROM_BANK2_END - DATA_EEPROM_BANK2_BASE)
+#else
+  #error "Cannot determine EEPROM size"
+#endif
+
+#if defined(STM32L0_CONFIG_EEPROM_RESERVED)
+  static_assert(STM32L0_CONFIG_EEPROM_RESERVED <= REAL_E2END + 1, "STM32L0_CONFIG_EEPROM_RESERVED bigger than EEPROM");
+  #define E2END (REAL_E2END - STM32L0_CONFIG_EEPROM_RESERVED)
+#else
+  #define E2END REAL_E2END
+#endif
+
 
 #endif
diff --git a/variants/B-L072Z-LRWAN1/variant.h b/variants/B-L072Z-LRWAN1/variant.h
index e1249656..52f11fcc 100644
--- a/variants/B-L072Z-LRWAN1/variant.h
+++ b/variants/B-L072Z-LRWAN1/variant.h
@@ -37,6 +37,9 @@
 #define STM32L0_CONFIG_HSECLK             0
 #define STM32L0_CONFIG_SYSOPT             0
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 /** Master clock frequency */
 #define VARIANT_MCK                       F_CPU
 
diff --git a/variants/Cicada-L082CZ/variant.h b/variants/Cicada-L082CZ/variant.h
index ac6b4304..1994bae4 100644
--- a/variants/Cicada-L082CZ/variant.h
+++ b/variants/Cicada-L082CZ/variant.h
@@ -46,6 +46,9 @@
 
 #define STM32L0_CONFIG_SFLASH_DATA_START  (256 * 1024)
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 #define USBCON
 
 /** Master clock frequency */
diff --git a/variants/Cricket-L082CZ/variant.h b/variants/Cricket-L082CZ/variant.h
index fbea4971..63ada1b3 100644
--- a/variants/Cricket-L082CZ/variant.h
+++ b/variants/Cricket-L082CZ/variant.h
@@ -52,6 +52,9 @@
 
 #define STM32L0_CONFIG_SFLASH_DATA_START  (256 * 1024)
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 #define USBCON
 
 /** Master clock frequency */
diff --git a/variants/Gnat-L082CZ/variant.h b/variants/Gnat-L082CZ/variant.h
index 5ec123e2..e46c1263 100644
--- a/variants/Gnat-L082CZ/variant.h
+++ b/variants/Gnat-L082CZ/variant.h
@@ -50,6 +50,9 @@
 #define STM32L0_CONFIG_PIN_GNSS_RX        STM32L0_GPIO_PIN_PA10_USART1_RX
 #define STM32L0_CONFIG_PIN_GNSS_TX        STM32L0_GPIO_PIN_PA9_USART1_TX
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 #define USBCON
 
 /** Master clock frequency */
diff --git a/variants/Grasshopper-L082CZ/variant.h b/variants/Grasshopper-L082CZ/variant.h
index 6048dac7..5fdd4e9d 100644
--- a/variants/Grasshopper-L082CZ/variant.h
+++ b/variants/Grasshopper-L082CZ/variant.h
@@ -42,6 +42,9 @@
 
 #define STM32L0_CONFIG_SFLASH_DATA_START  (256 * 1024)
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 #define USBCON
 
 /** Master clock frequency */
diff --git a/variants/I-NUCLEO-LRWAN1/variant.h b/variants/I-NUCLEO-LRWAN1/variant.h
index 2c092dde..552293b6 100644
--- a/variants/I-NUCLEO-LRWAN1/variant.h
+++ b/variants/I-NUCLEO-LRWAN1/variant.h
@@ -37,6 +37,9 @@
 #define STM32L0_CONFIG_HSECLK             0
 #define STM32L0_CONFIG_SYSOPT             0
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 /** Master clock frequency */
 #define VARIANT_MCK                       F_CPU
 
diff --git a/variants/NUCLEO-L073RZ/variant.h b/variants/NUCLEO-L073RZ/variant.h
index 5036804f..157c1720 100644
--- a/variants/NUCLEO-L073RZ/variant.h
+++ b/variants/NUCLEO-L073RZ/variant.h
@@ -37,6 +37,9 @@
 #define STM32L0_CONFIG_HSECLK             0
 #define STM32L0_CONFIG_SYSOPT             0
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 /** Master clock frequency */
 #define VARIANT_MCK                       F_CPU
 
diff --git a/variants/P-NUCLEO-LRWAN1/variant.h b/variants/P-NUCLEO-LRWAN1/variant.h
index 1ee4f78d..b717fa2f 100644
--- a/variants/P-NUCLEO-LRWAN1/variant.h
+++ b/variants/P-NUCLEO-LRWAN1/variant.h
@@ -37,6 +37,9 @@
 #define STM32L0_CONFIG_HSECLK             0
 #define STM32L0_CONFIG_SYSOPT             0
 
+// Reserve some room at the end of EEPROM for LoRaWAN library
+#define STM32L0_CONFIG_EEPROM_RESERVED    2048
+
 /** Master clock frequency */
 #define VARIANT_MCK                       F_CPU