3 files changed, 49 insertions, 25 deletions

diff --git a/platforms/eeprom.h b/platforms/eeprom.h
index fbfef20334..8e69eecc4c 100644
--- a/platforms/eeprom.h
+++ b/platforms/eeprom.h
@@ -22,6 +22,10 @@ void     eeprom_update_dword(uint32_t *__p, uint32_t __value);
 void     eeprom_update_block(const void *__src, void *__dst, size_t __n);
 #endif
 
+static inline void eeprom_write_qword(uint64_t *__p, uint64_t __value) {
+    eeprom_update_block(&__value, __p, sizeof(uint64_t));
+}
+
 #if defined(EEPROM_CUSTOM)
 #    ifndef EEPROM_SIZE
 #        error EEPROM_SIZE has not been defined for custom driver.
diff --git a/quantum/eeconfig.c b/quantum/eeconfig.c
index 2d2180b4b4..40690d6a97 100644
--- a/quantum/eeconfig.c
+++ b/quantum/eeconfig.c
@@ -19,6 +19,8 @@ void via_eeprom_set_valid(bool valid);
 void eeconfig_init_via(void);
 #endif
 
+_Static_assert((intptr_t)EECONFIG_HANDEDNESS == 14, "EEPROM handedness offset is incorrect");
+
 /** \brief eeconfig enable
  *
  * FIXME: needs doc
@@ -57,11 +59,9 @@ void eeconfig_init_quantum(void) {
     eeprom_update_byte(EECONFIG_AUDIO, 0);
     eeprom_update_dword(EECONFIG_RGBLIGHT, 0);
     eeprom_update_byte(EECONFIG_RGBLIGHT_EXTENDED, 0);
-    eeprom_update_byte(EECONFIG_UNUSED, 0);
     eeprom_update_byte(EECONFIG_UNICODEMODE, 0);
     eeprom_update_byte(EECONFIG_STENOMODE, 0);
-    uint64_t dummy = 0;
-    eeprom_update_block(&dummy, EECONFIG_RGB_MATRIX, sizeof(uint64_t));
+    eeprom_write_qword(EECONFIG_RGB_MATRIX, 0);
     eeprom_update_dword(EECONFIG_HAPTIC, 0);
 #if defined(HAPTIC_ENABLE)
     haptic_reset();
diff --git a/quantum/eeconfig.h b/quantum/eeconfig.h
index d7cce166bd..fa0dd799d1 100644
--- a/quantum/eeconfig.h
+++ b/quantum/eeconfig.h
@@ -19,37 +19,57 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <stddef.h> // offsetof
 #include "eeprom.h"
+#include "util.h"
 
 #ifndef EECONFIG_MAGIC_NUMBER
-#    define EECONFIG_MAGIC_NUMBER (uint16_t)0xFEE6 // When changing, decrement this value to avoid future re-init issues
+#    define EECONFIG_MAGIC_NUMBER (uint16_t)0xFEE5 // When changing, decrement this value to avoid future re-init issues
 #endif
 #define EECONFIG_MAGIC_NUMBER_OFF (uint16_t)0xFFFF
 
+// Dummy struct only used to calculate offsets
+typedef struct PACKED {
+    uint16_t magic;
+    uint8_t  debug;
+    uint8_t  default_layer;
+    uint16_t keymap;
+    uint8_t  backlight;
+    uint8_t  audio;
+    uint32_t rgblight;
+    uint8_t  unicode;
+    uint8_t  steno;
+    uint8_t  handedness;
+    uint32_t keyboard;
+    uint32_t user;
+    union { // Mutually exclusive
+        uint32_t led_matrix;
+        uint64_t rgb_matrix;
+    };
+    uint32_t haptic;
+    uint8_t  rgblight_ext;
+} eeprom_core_t;
+
 /* EEPROM parameter address */
-#define EECONFIG_MAGIC (uint16_t *)0
-#define EECONFIG_DEBUG (uint8_t *)2
-#define EECONFIG_DEFAULT_LAYER (uint8_t *)3
-#define EECONFIG_KEYMAP (uint16_t *)4
-#define EECONFIG_BACKLIGHT (uint8_t *)6
-#define EECONFIG_AUDIO (uint8_t *)7
-#define EECONFIG_RGBLIGHT (uint32_t *)8
-#define EECONFIG_UNICODEMODE (uint8_t *)12
-#define EECONFIG_STENOMODE (uint8_t *)13
-// EEHANDS for two handed boards
-#define EECONFIG_HANDEDNESS (uint8_t *)14
-#define EECONFIG_KEYBOARD (uint32_t *)15
-#define EECONFIG_USER (uint32_t *)19
-#define EECONFIG_UNUSED (uint8_t *)23
-// Mutually exclusive
-#define EECONFIG_LED_MATRIX (uint32_t *)24
-#define EECONFIG_RGB_MATRIX (uint64_t *)24
-
-#define EECONFIG_HAPTIC (uint32_t *)32
-#define EECONFIG_RGBLIGHT_EXTENDED (uint8_t *)36
+#define EECONFIG_MAGIC (uint16_t *)(offsetof(eeprom_core_t, magic))
+#define EECONFIG_DEBUG (uint8_t *)(offsetof(eeprom_core_t, debug))
+#define EECONFIG_DEFAULT_LAYER (uint8_t *)(offsetof(eeprom_core_t, default_layer))
+#define EECONFIG_KEYMAP (uint16_t *)(offsetof(eeprom_core_t, keymap))
+#define EECONFIG_BACKLIGHT (uint8_t *)(offsetof(eeprom_core_t, backlight))
+#define EECONFIG_AUDIO (uint8_t *)(offsetof(eeprom_core_t, audio))
+#define EECONFIG_RGBLIGHT (uint32_t *)(offsetof(eeprom_core_t, rgblight))
+#define EECONFIG_UNICODEMODE (uint8_t *)(offsetof(eeprom_core_t, unicode))
+#define EECONFIG_STENOMODE (uint8_t *)(offsetof(eeprom_core_t, steno))
+#define EECONFIG_HANDEDNESS (uint8_t *)(offsetof(eeprom_core_t, handedness))
+#define EECONFIG_KEYBOARD (uint32_t *)(offsetof(eeprom_core_t, keyboard))
+#define EECONFIG_USER (uint32_t *)(offsetof(eeprom_core_t, user))
+#define EECONFIG_LED_MATRIX (uint32_t *)(offsetof(eeprom_core_t, led_matrix))
+#define EECONFIG_RGB_MATRIX (uint64_t *)(offsetof(eeprom_core_t, rgb_matrix))
+#define EECONFIG_HAPTIC (uint32_t *)(offsetof(eeprom_core_t, haptic))
+#define EECONFIG_RGBLIGHT_EXTENDED (uint8_t *)(offsetof(eeprom_core_t, rgblight_ext))
 
 // Size of EEPROM being used for core data storage
-#define EECONFIG_BASE_SIZE 37
+#define EECONFIG_BASE_SIZE ((uint8_t)sizeof(eeprom_core_t))
 
 // Size of EEPROM dedicated to keyboard- and user-specific data
 #ifndef EECONFIG_KB_DATA_SIZE