Don't make EEPROM size assumptions with dynamic keymaps. (#16054)

* Don't make EEPROM size assumptions with dynamic keymaps.

* Add support for checking against emulated flash, error out if someone attempts to build a board without specifying EEPROM size.

* Reorder defines so that MCU is considered last.

* Refactor EEPROM definitions for simplicity.

* Fix max sizing of kabedon/kabedon980.

* Fix max sizing of mechlovin/olly/jf.

* Fix unit tests.

* Review comments, add messages with values during build failures.

17 files changed, 185 insertions, 153 deletions

diff --git a/common_features.mk b/common_features.mk
index d3da487e69..5c5e6a9a25 100644
--- a/common_features.mk
+++ b/common_features.mk
@@ -186,20 +186,21 @@ else
     else ifeq ($(PLATFORM),CHIBIOS)
       ifneq ($(filter STM32F3xx_% STM32F1xx_% %_STM32F401xC %_STM32F401xE %_STM32F405xG %_STM32F411xE %_STM32F072xB %_STM32F042x6 %_GD32VF103xB %_GD32VF103x8, $(MCU_SERIES)_$(MCU_LDSCRIPT)),)
         # Emulated EEPROM
-        OPT_DEFS += -DEEPROM_DRIVER
+        OPT_DEFS += -DEEPROM_DRIVER -DEEPROM_STM32_FLASH_EMULATED
         COMMON_VPATH += $(DRIVER_PATH)/eeprom
         SRC += eeprom_driver.c
         SRC += $(PLATFORM_COMMON_DIR)/eeprom_stm32.c
         SRC += $(PLATFORM_COMMON_DIR)/flash_stm32.c
       else ifneq ($(filter $(MCU_SERIES),STM32L0xx STM32L1xx),)
         # True EEPROM on STM32L0xx, L1xx
-        OPT_DEFS += -DEEPROM_DRIVER
+        OPT_DEFS += -DEEPROM_DRIVER -DEEPROM_STM32_L0_L1
         COMMON_VPATH += $(DRIVER_PATH)/eeprom
         COMMON_VPATH += $(PLATFORM_PATH)/$(PLATFORM_KEY)/$(DRIVER_DIR)/eeprom
         SRC += eeprom_driver.c
         SRC += eeprom_stm32_L0_L1.c
       else ifneq ($(filter $(MCU_SERIES),KL2x K20x),)
         # Teensy EEPROM implementations
+        OPT_DEFS += -DEEPROM_TEENSY
         SRC += eeprom_teensy.c
       else
         # Fall back to transient, i.e. non-persistent
@@ -209,9 +210,11 @@ else
       endif
     else ifeq ($(PLATFORM),ARM_ATSAM)
       # arm_atsam EEPROM
-      SRC += $(PLATFORM_COMMON_DIR)/eeprom.c
+      OPT_DEFS += -DEEPROM_SAMD
+      SRC += $(PLATFORM_COMMON_DIR)/eeprom_samd.c
     else ifeq ($(PLATFORM),TEST)
       # Test harness "EEPROM"
+      OPT_DEFS += -DEEPROM_TEST_HARNESS
       SRC += $(PLATFORM_COMMON_DIR)/eeprom.c
     endif
   endif
diff --git a/keyboards/kabedon/kabedon980/config.h b/keyboards/kabedon/kabedon980/config.h
index 5dc70dfebf..db93dfcf85 100644
--- a/keyboards/kabedon/kabedon980/config.h
+++ b/keyboards/kabedon/kabedon980/config.h
@@ -32,21 +32,21 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COLS 13
 
 /* Keyboard Matrix Assignments */
-#define MATRIX_ROW_PINS {D0,D2,F7,B1,B0,D6,C7,D7,B5,B2} 
-#define MATRIX_COL_PINS {F5,F4,F6,C6,B6,B4,D3,D1,D4,F1,B3,D5,F0}  
+#define MATRIX_ROW_PINS {D0,D2,F7,B1,B0,D6,C7,D7,B5,B2}
+#define MATRIX_COL_PINS {F5,F4,F6,C6,B6,B4,D3,D1,D4,F1,B3,D5,F0}
 #define UNUSED_PINS
-#define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 2047
+#define DYNAMIC_KEYMAP_LAYER_COUNT 3
 /* COL2ROW, ROW2COL*/
 #define DIODE_DIRECTION ROW2COL
 
-#define RGB_DI_PIN B7  
+#define RGB_DI_PIN B7
 #ifdef RGB_DI_PIN
   #define RGBLED_NUM 20
   #define RGBLIGHT_HUE_STEP 8
   #define RGBLIGHT_SAT_STEP 8
   #define RGBLIGHT_VAL_STEP 8
   #define RGBLIGHT_LIMIT_VAL 255 /* The maximum brightness level */
-  #define RGBLIGHT_ANIMATIONS 
+  #define RGBLIGHT_ANIMATIONS
 #endif
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/kabedon/kabedon980/keymaps/via/keymap.c b/keyboards/kabedon/kabedon980/keymaps/via/keymap.c
index 44574452bf..76eaa3968a 100644
--- a/keyboards/kabedon/kabedon980/keymaps/via/keymap.c
+++ b/keyboards/kabedon/kabedon980/keymaps/via/keymap.c
@@ -6,32 +6,24 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     KC_ESC,           KC_F1,   KC_F2,  KC_F3,  KC_F4,  KC_F5,  KC_F6,  KC_F7,    KC_F8,   KC_F9,    KC_F10,   KC_F11,   KC_F12,      KC_DEL,  KC_HOME, KC_PGUP, KC_PGDN,
     KC_GRV,  KC_1,    KC_2,    KC_3,   KC_4,   KC_5,   KC_6,   KC_7,   KC_8,     KC_9,    KC_0,     KC_MINS,  KC_EQL,   KC_BSPC,     KC_NLCK, KC_PSLS, KC_PAST, KC_PMNS,
     KC_TAB,  KC_Q,    KC_W,    KC_E,   KC_R,   KC_T,   KC_Y,   KC_U,   KC_I,     KC_O,    KC_P,     KC_LBRC,  KC_RBRC,  KC_BSLS,     KC_P7,   KC_P8,   KC_P9,   KC_PPLS,
-    KC_CAPS, KC_A,    KC_S,    KC_D,   KC_F,   KC_G,   KC_H,   KC_J,   KC_K,     KC_L,    KC_SCLN,  KC_QUOT,      KC_ENT,            KC_P4,   KC_P5,   KC_P6,    
+    KC_CAPS, KC_A,    KC_S,    KC_D,   KC_F,   KC_G,   KC_H,   KC_J,   KC_K,     KC_L,    KC_SCLN,  KC_QUOT,      KC_ENT,            KC_P4,   KC_P5,   KC_P6,
     KC_LSFT, KC_Z,    KC_X,    KC_C,   KC_V,   KC_B,   KC_N,   KC_M,   KC_COMM,  KC_DOT,  KC_SLSH,  KC_RSFT,            KC_UP,       KC_P1,   KC_P2,   KC_P3,   KC_PENT,
     KC_LCTL, KC_LGUI, KC_LALT,                 KC_SPC,                           KC_RALT, MO(1),    KC_RCTL,  KC_LEFT,  KC_DOWN,  KC_RGHT,   KC_P0,       KC_PDOT  ),
-    
+
   [1] = LAYOUT(
     RGB_MOD,          RGB_TOG, RGB_SAI, RGB_SAD, RGB_HUI, RGB_HUD, RGB_SPI, RGB_SPD, RGB_VAI, RGB_VAD, KC_TRNS, KC_TRNS,  KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,     KC_TRNS,         KC_TRNS, KC_TRNS, KC_TRNS, 
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,     KC_TRNS,         KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,   KC_TRNS,      KC_TRNS ),
-    
+
   [2] = LAYOUT(
-    KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+    KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,     KC_TRNS,         KC_TRNS, KC_TRNS, KC_TRNS, 
+    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,     KC_TRNS,         KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
     KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,   KC_TRNS,      KC_TRNS ),
-    
-  [3] = LAYOUT(
-    KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,     KC_TRNS,         KC_TRNS, KC_TRNS, KC_TRNS, 
-    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,    KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-    KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,   KC_TRNS,      KC_TRNS )
 };
 
diff --git a/keyboards/mechlovin/olly/jf/keymaps/via/config.h b/keyboards/mechlovin/olly/jf/keymaps/via/config.h
index f330025a00..82c2e51eb9 100644
--- a/keyboards/mechlovin/olly/jf/keymaps/via/config.h
+++ b/keyboards/mechlovin/olly/jf/keymaps/via/config.h
@@ -17,6 +17,4 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #pragma once
 
-#define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 1607
-#define DYNAMIC_KEYMAP_LAYER_COUNT 6
-
+#define DYNAMIC_KEYMAP_LAYER_COUNT 3
diff --git a/keyboards/mechlovin/olly/jf/keymaps/via/keymap.c b/keyboards/mechlovin/olly/jf/keymaps/via/keymap.c
index c90eeb1830..18ac685abc 100644
--- a/keyboards/mechlovin/olly/jf/keymaps/via/keymap.c
+++ b/keyboards/mechlovin/olly/jf/keymaps/via/keymap.c
@@ -40,29 +40,4 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
         KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
         KC_TRNS,  KC_TRNS, KC_TRNS,                            KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS
     ),
-    [3] = LAYOUT_all(
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS,                            KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS
-    ),
-    [4] = LAYOUT_all(
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS,                            KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS
-    ),
-    [5] = LAYOUT_all(
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
-        KC_TRNS,  KC_TRNS, KC_TRNS,                            KC_TRNS,                            KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS, KC_TRNS
-    ),
-
 };
\ No newline at end of file
diff --git a/platforms/arm_atsam/eeprom.c b/platforms/arm_atsam/eeprom_samd.c
index ff1a692623..beaffeec30 100644
--- a/platforms/arm_atsam/eeprom.c
+++ b/platforms/arm_atsam/eeprom_samd.c
@@ -18,11 +18,7 @@
 #include "samd51j18a.h"
 #include "core_cm4.h"
 #include "component/nvmctrl.h"
-
-#ifndef EEPROM_SIZE
-#    include "eeconfig.h"
-#    define EEPROM_SIZE (((EECONFIG_SIZE + 3) / 4) * 4)  // based off eeconfig's current usage, aligned to 4-byte sizes, to deal with LTO
-#endif
+#include "eeprom_samd.h"
 
 #ifndef MAX
 #    define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
diff --git a/platforms/arm_atsam/eeprom_samd.h b/platforms/arm_atsam/eeprom_samd.h
new file mode 100755
index 0000000000..7dbff9bfa1
--- /dev/null
+++ b/platforms/arm_atsam/eeprom_samd.h
@@ -0,0 +1,8 @@
+// Copyright 2022 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#pragma once
+
+#ifndef EEPROM_SIZE
+#    include "eeconfig.h"
+#    define EEPROM_SIZE (((EECONFIG_SIZE + 3) / 4) * 4)  // based off eeconfig's current usage, aligned to 4-byte sizes, to deal with LTO
+#endif
diff --git a/platforms/chibios/eeprom_stm32.c b/platforms/chibios/eeprom_stm32.c
index acc6a48516..8bf0b19c3d 100644
--- a/platforms/chibios/eeprom_stm32.c
+++ b/platforms/chibios/eeprom_stm32.c
@@ -133,10 +133,6 @@
  */
 
 #include "eeprom_stm32_defs.h"
-#if !defined(FEE_PAGE_SIZE) || !defined(FEE_PAGE_COUNT) || !defined(FEE_MCU_FLASH_SIZE) || !defined(FEE_PAGE_BASE_ADDRESS)
-#    error "not implemented."
-#endif
-
 /* These bits are used for optimizing encoding of bytes, 0 and 1 */
 #define FEE_WORD_ENCODING 0x8000
 #define FEE_VALUE_NEXT 0x6000
@@ -144,69 +140,11 @@
 #define FEE_VALUE_ENCODED 0x2000
 #define FEE_BYTE_RANGE 0x80
 
-/* Addressable range 16KByte: 0 <-> (0x1FFF << 1) */
-#define FEE_ADDRESS_MAX_SIZE 0x4000
-
 /* Flash word value after erase */
 #define FEE_EMPTY_WORD ((uint16_t)0xFFFF)
 
-/* Size of combined compacted eeprom and write log pages */
-#define FEE_DENSITY_MAX_SIZE (FEE_PAGE_COUNT * FEE_PAGE_SIZE)
-
-#ifndef FEE_MCU_FLASH_SIZE_IGNORE_CHECK /* *TODO: Get rid of this check */
-#    if FEE_DENSITY_MAX_SIZE > (FEE_MCU_FLASH_SIZE * 1024)
-#        pragma message STR(FEE_DENSITY_MAX_SIZE) " > " STR(FEE_MCU_FLASH_SIZE * 1024)
-#        error emulated eeprom: FEE_DENSITY_MAX_SIZE is greater than available flash size
-#    endif
-#endif
-
-/* Size of emulated eeprom */
-#ifdef FEE_DENSITY_BYTES
-#    if (FEE_DENSITY_BYTES > FEE_DENSITY_MAX_SIZE)
-#        pragma message STR(FEE_DENSITY_BYTES) " > " STR(FEE_DENSITY_MAX_SIZE)
-#        error emulated eeprom: FEE_DENSITY_BYTES exceeds FEE_DENSITY_MAX_SIZE
-#    endif
-#    if (FEE_DENSITY_BYTES == FEE_DENSITY_MAX_SIZE)
-#        pragma message STR(FEE_DENSITY_BYTES) " == " STR(FEE_DENSITY_MAX_SIZE)
-#        warning emulated eeprom: FEE_DENSITY_BYTES leaves no room for a write log.  This will greatly increase the flash wear rate!
-#    endif
-#    if FEE_DENSITY_BYTES > FEE_ADDRESS_MAX_SIZE
-#        pragma message STR(FEE_DENSITY_BYTES) " > " STR(FEE_ADDRESS_MAX_SIZE)
-#        error emulated eeprom: FEE_DENSITY_BYTES is greater than FEE_ADDRESS_MAX_SIZE allows
-#    endif
-#    if ((FEE_DENSITY_BYTES) % 2) == 1
-#        error emulated eeprom: FEE_DENSITY_BYTES must be even
-#    endif
-#else
-/* Default to half of allocated space used for emulated eeprom, half for write log */
-#    define FEE_DENSITY_BYTES (FEE_PAGE_COUNT * FEE_PAGE_SIZE / 2)
-#endif
-
-/* Size of write log */
-#ifdef FEE_WRITE_LOG_BYTES
-#    if ((FEE_DENSITY_BYTES + FEE_WRITE_LOG_BYTES) > FEE_DENSITY_MAX_SIZE)
-#        pragma message STR(FEE_DENSITY_BYTES) " + " STR(FEE_WRITE_LOG_BYTES) " > " STR(FEE_DENSITY_MAX_SIZE)
-#        error emulated eeprom: FEE_WRITE_LOG_BYTES exceeds remaining FEE_DENSITY_MAX_SIZE
-#    endif
-#    if ((FEE_WRITE_LOG_BYTES) % 2) == 1
-#        error emulated eeprom: FEE_WRITE_LOG_BYTES must be even
-#    endif
-#else
-/* Default to use all remaining space */
-#    define FEE_WRITE_LOG_BYTES (FEE_PAGE_COUNT * FEE_PAGE_SIZE - FEE_DENSITY_BYTES)
-#endif
-
-/* Start of the emulated eeprom compacted flash area */
-#define FEE_COMPACTED_BASE_ADDRESS FEE_PAGE_BASE_ADDRESS
-/* End of the emulated eeprom compacted flash area */
-#define FEE_COMPACTED_LAST_ADDRESS (FEE_COMPACTED_BASE_ADDRESS + FEE_DENSITY_BYTES)
-/* Start of the emulated eeprom write log */
-#define FEE_WRITE_LOG_BASE_ADDRESS FEE_COMPACTED_LAST_ADDRESS
-/* End of the emulated eeprom write log */
-#define FEE_WRITE_LOG_LAST_ADDRESS (FEE_WRITE_LOG_BASE_ADDRESS + FEE_WRITE_LOG_BYTES)
-
-#if defined(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) && (DYNAMIC_KEYMAP_EEPROM_MAX_ADDR >= FEE_DENSITY_BYTES)
-#    error emulated eeprom: DYNAMIC_KEYMAP_EEPROM_MAX_ADDR is greater than the FEE_DENSITY_BYTES available
+#if !defined(FEE_PAGE_SIZE) || !defined(FEE_PAGE_COUNT) || !defined(FEE_MCU_FLASH_SIZE) || !defined(FEE_PAGE_BASE_ADDRESS)
+#    error "not implemented."
 #endif
 
 /* In-memory contents of emulated eeprom for faster access */
diff --git a/platforms/chibios/eeprom_stm32_defs.h b/platforms/chibios/eeprom_stm32_defs.h
index 66904f247f..581434eb5e 100644
--- a/platforms/chibios/eeprom_stm32_defs.h
+++ b/platforms/chibios/eeprom_stm32_defs.h
@@ -72,3 +72,65 @@
 #        define FEE_PAGE_BASE_ADDRESS ((uintptr_t)(FEE_FLASH_BASE) + FEE_MCU_FLASH_SIZE * 1024 - (FEE_PAGE_COUNT * FEE_PAGE_SIZE))
 #    endif
 #endif
+
+/* Addressable range 16KByte: 0 <-> (0x1FFF << 1) */
+#define FEE_ADDRESS_MAX_SIZE 0x4000
+
+/* Size of combined compacted eeprom and write log pages */
+#define FEE_DENSITY_MAX_SIZE (FEE_PAGE_COUNT * FEE_PAGE_SIZE)
+
+#ifndef FEE_MCU_FLASH_SIZE_IGNORE_CHECK /* *TODO: Get rid of this check */
+#    if FEE_DENSITY_MAX_SIZE > (FEE_MCU_FLASH_SIZE * 1024)
+#        pragma message STR(FEE_DENSITY_MAX_SIZE) " > " STR(FEE_MCU_FLASH_SIZE * 1024)
+#        error emulated eeprom: FEE_DENSITY_MAX_SIZE is greater than available flash size
+#    endif
+#endif
+
+/* Size of emulated eeprom */
+#ifdef FEE_DENSITY_BYTES
+#    if (FEE_DENSITY_BYTES > FEE_DENSITY_MAX_SIZE)
+#        pragma message STR(FEE_DENSITY_BYTES) " > " STR(FEE_DENSITY_MAX_SIZE)
+#        error emulated eeprom: FEE_DENSITY_BYTES exceeds FEE_DENSITY_MAX_SIZE
+#    endif
+#    if (FEE_DENSITY_BYTES == FEE_DENSITY_MAX_SIZE)
+#        pragma message STR(FEE_DENSITY_BYTES) " == " STR(FEE_DENSITY_MAX_SIZE)
+#        warning emulated eeprom: FEE_DENSITY_BYTES leaves no room for a write log.  This will greatly increase the flash wear rate!
+#    endif
+#    if FEE_DENSITY_BYTES > FEE_ADDRESS_MAX_SIZE
+#        pragma message STR(FEE_DENSITY_BYTES) " > " STR(FEE_ADDRESS_MAX_SIZE)
+#        error emulated eeprom: FEE_DENSITY_BYTES is greater than FEE_ADDRESS_MAX_SIZE allows
+#    endif
+#    if ((FEE_DENSITY_BYTES) % 2) == 1
+#        error emulated eeprom: FEE_DENSITY_BYTES must be even
+#    endif
+#else
+/* Default to half of allocated space used for emulated eeprom, half for write log */
+#    define FEE_DENSITY_BYTES (FEE_PAGE_COUNT * FEE_PAGE_SIZE / 2)
+#endif
+
+/* Size of write log */
+#ifdef FEE_WRITE_LOG_BYTES
+#    if ((FEE_DENSITY_BYTES + FEE_WRITE_LOG_BYTES) > FEE_DENSITY_MAX_SIZE)
+#        pragma message STR(FEE_DENSITY_BYTES) " + " STR(FEE_WRITE_LOG_BYTES) " > " STR(FEE_DENSITY_MAX_SIZE)
+#        error emulated eeprom: FEE_WRITE_LOG_BYTES exceeds remaining FEE_DENSITY_MAX_SIZE
+#    endif
+#    if ((FEE_WRITE_LOG_BYTES) % 2) == 1
+#        error emulated eeprom: FEE_WRITE_LOG_BYTES must be even
+#    endif
+#else
+/* Default to use all remaining space */
+#    define FEE_WRITE_LOG_BYTES (FEE_PAGE_COUNT * FEE_PAGE_SIZE - FEE_DENSITY_BYTES)
+#endif
+
+/* Start of the emulated eeprom compacted flash area */
+#define FEE_COMPACTED_BASE_ADDRESS FEE_PAGE_BASE_ADDRESS
+/* End of the emulated eeprom compacted flash area */
+#define FEE_COMPACTED_LAST_ADDRESS (FEE_COMPACTED_BASE_ADDRESS + FEE_DENSITY_BYTES)
+/* Start of the emulated eeprom write log */
+#define FEE_WRITE_LOG_BASE_ADDRESS FEE_COMPACTED_LAST_ADDRESS
+/* End of the emulated eeprom write log */
+#define FEE_WRITE_LOG_LAST_ADDRESS (FEE_WRITE_LOG_BASE_ADDRESS + FEE_WRITE_LOG_BYTES)
+
+#if defined(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) && (DYNAMIC_KEYMAP_EEPROM_MAX_ADDR >= FEE_DENSITY_BYTES)
+#    error emulated eeprom: DYNAMIC_KEYMAP_EEPROM_MAX_ADDR is greater than the FEE_DENSITY_BYTES available
+#endif
diff --git a/platforms/chibios/eeprom_teensy.c b/platforms/chibios/eeprom_teensy.c
index 2093f9b4b2..575f51526e 100644
--- a/platforms/chibios/eeprom_teensy.c
+++ b/platforms/chibios/eeprom_teensy.c
@@ -1,6 +1,7 @@
 #include <ch.h>
 #include <hal.h>
 
+#include "eeprom_teensy.h"
 #include "eeconfig.h"
 
 /*************************************/
@@ -42,18 +43,6 @@
 #if defined(K20x) /* chip selection */
 /* Teensy 3.0, 3.1, 3.2; mchck; infinity keyboard */
 
-// The EEPROM is really RAM with a hardware-based backup system to
-// flash memory.  Selecting a smaller size EEPROM allows more wear
-// leveling, for higher write endurance.  If you edit this file,
-// set this to the smallest size your application can use.  Also,
-// due to Freescale's implementation, writing 16 or 32 bit words
-// (aligned to 2 or 4 byte boundaries) has twice the endurance
-// compared to writing 8 bit bytes.
-//
-#    ifndef EEPROM_SIZE
-#        define EEPROM_SIZE 32
-#    endif
-
 /*
     ^^^ Here be dragons:
         NXP AppNote AN4282 section 3.1 states that partitioning must only be done once.
@@ -350,8 +339,6 @@ void do_flash_cmd(volatile uint8_t *fstat)
 extern uint32_t __eeprom_workarea_start__;
 extern uint32_t __eeprom_workarea_end__;
 
-#    define EEPROM_SIZE 128
-
 static uint32_t flashend = 0;
 
 void eeprom_initialize(void) {
diff --git a/platforms/chibios/eeprom_teensy.h b/platforms/chibios/eeprom_teensy.h
new file mode 100755
index 0000000000..ead5998b29
--- /dev/null
+++ b/platforms/chibios/eeprom_teensy.h
@@ -0,0 +1,22 @@
+// Copyright 2022 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#pragma once
+
+#if defined(K20x)
+/* Teensy 3.0, 3.1, 3.2; mchck; infinity keyboard */
+// The EEPROM is really RAM with a hardware-based backup system to
+// flash memory.  Selecting a smaller size EEPROM allows more wear
+// leveling, for higher write endurance.  If you edit this file,
+// set this to the smallest size your application can use.  Also,
+// due to Freescale's implementation, writing 16 or 32 bit words
+// (aligned to 2 or 4 byte boundaries) has twice the endurance
+// compared to writing 8 bit bytes.
+//
+#    ifndef EEPROM_SIZE
+#        define EEPROM_SIZE 32
+#    endif
+#elif defined(KL2x) /* Teensy LC (emulated) */
+#    define EEPROM_SIZE 128
+#else
+#    error Unsupported Teensy EEPROM.
+#endif
diff --git a/platforms/eeprom.h b/platforms/eeprom.h
index f5b3f0ad53..091e6e4400 100644
--- a/platforms/eeprom.h
+++ b/platforms/eeprom.h
@@ -1,3 +1,5 @@
+// Copyright 2018-2022 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
 
 #if defined(__AVR__) && !defined(EEPROM_DRIVER)
@@ -19,3 +21,50 @@ void     eeprom_update_word(uint16_t *__p, uint16_t __value);
 void     eeprom_update_dword(uint32_t *__p, uint32_t __value);
 void     eeprom_update_block(const void *__src, void *__dst, size_t __n);
 #endif
+
+#if defined(EEPROM_CUSTOM)
+#    ifndef EEPROM_SIZE
+#        error EEPROM_SIZE has not been defined for custom driver.
+#    endif
+#    define TOTAL_EEPROM_BYTE_COUNT (EEPROM_SIZE)
+#elif defined(EEPROM_TRANSIENT)
+#    include "eeprom_transient.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (TRANSIENT_EEPROM_SIZE)
+#elif defined(EEPROM_I2C)
+#    include "eeprom_i2c.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (EXTERNAL_EEPROM_BYTE_COUNT)
+#elif defined(EEPROM_SPI)
+#    include "eeprom_spi.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (EXTERNAL_EEPROM_BYTE_COUNT)
+#elif defined(EEPROM_STM32_L0_L1)
+#    include "eeprom_stm32_L0_L1.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (STM32_ONBOARD_EEPROM_SIZE)
+#elif defined(EEPROM_TEENSY)
+#    include "eeprom_teensy.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (EEPROM_SIZE)
+#elif defined(EEPROM_STM32_FLASH_EMULATED)
+#    include "eeprom_stm32_defs.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (FEE_DENSITY_BYTES)
+#elif defined(EEPROM_SAMD)
+#    include "eeprom_samd.h"
+#    define TOTAL_EEPROM_BYTE_COUNT (EEPROM_SIZE)
+#elif defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega16U4__) || defined(__AVR_AT90USB162__) || defined(__AVR_ATtiny85__)
+#    define TOTAL_EEPROM_BYTE_COUNT 512
+#elif defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega32A__)
+#    define TOTAL_EEPROM_BYTE_COUNT 1024
+#elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__)
+#    define TOTAL_EEPROM_BYTE_COUNT 2048
+#elif defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
+#    define TOTAL_EEPROM_BYTE_COUNT 4096
+#elif defined(EEPROM_TEST_HARNESS)
+#    ifndef FLASH_STM32_MOCKED
+// Normal tests
+#        define TOTAL_EEPROM_BYTE_COUNT 32
+#    else
+// Flash wear-leveling testing
+#        include "eeprom_stm32_tests.h"
+#        define TOTAL_EEPROM_BYTE_COUNT (EEPROM_SIZE)
+#    endif
+#else
+#    error Unknown EEPROM driver.
+#endif
diff --git a/platforms/test/eeprom.c b/platforms/test/eeprom.c
index 5c8e69dae3..e292faa644 100644
--- a/platforms/test/eeprom.c
+++ b/platforms/test/eeprom.c
@@ -16,9 +16,7 @@
 
 #include "eeprom.h"
 
-#define EEPROM_SIZE 32
-
-static uint8_t buffer[EEPROM_SIZE];
+static uint8_t buffer[TOTAL_EEPROM_BYTE_COUNT];
 
 uint8_t eeprom_read_byte(const uint8_t *addr) {
     uintptr_t offset = (uintptr_t)addr;
diff --git a/platforms/test/eeprom_stm32_tests.cpp b/platforms/test/eeprom_stm32_tests.cpp
index 5bc8d87900..57f31d634f 100644
--- a/platforms/test/eeprom_stm32_tests.cpp
+++ b/platforms/test/eeprom_stm32_tests.cpp
@@ -17,8 +17,6 @@
 #include "gtest/gtest.h"
 
 extern "C" {
-#include "flash_stm32.h"
-#include "eeprom_stm32.h"
 #include "eeprom.h"
 }
 
@@ -46,7 +44,6 @@ extern "C" {
  *
  */
 
-#define EEPROM_SIZE (FEE_PAGE_SIZE * FEE_PAGE_COUNT / 2)
 #define LOG_SIZE EEPROM_SIZE
 #define LOG_BASE (MOCK_FLASH_SIZE - LOG_SIZE)
 #define EEPROM_BASE (LOG_BASE - EEPROM_SIZE)
diff --git a/platforms/test/eeprom_stm32_tests.h b/platforms/test/eeprom_stm32_tests.h
new file mode 100644
index 0000000000..35ed885e52
--- /dev/null
+++ b/platforms/test/eeprom_stm32_tests.h
@@ -0,0 +1,8 @@
+// Copyright 2018-2022 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#pragma once
+
+#include "flash_stm32.h"
+#include "eeprom_stm32.h"
+
+#define EEPROM_SIZE (FEE_PAGE_SIZE * FEE_PAGE_COUNT / 2)
diff --git a/platforms/test/rules.mk b/platforms/test/rules.mk
index 66b853d8ee..55512c7392 100644
--- a/platforms/test/rules.mk
+++ b/platforms/test/rules.mk
@@ -1,4 +1,4 @@
-eeprom_stm32_DEFS  := -DFLASH_STM32_MOCKED -DNO_PRINT -DFEE_FLASH_BASE=FlashBuf
+eeprom_stm32_DEFS  := -DEEPROM_TEST_HARNESS -DFLASH_STM32_MOCKED -DNO_PRINT -DFEE_FLASH_BASE=FlashBuf
 eeprom_stm32_tiny_DEFS := $(eeprom_stm32_DEFS) \
 	-DFEE_MCU_FLASH_SIZE=1 \
 	-DMOCK_FLASH_SIZE=1024 \
diff --git a/quantum/dynamic_keymap.c b/quantum/dynamic_keymap.c
index 19a6bea59a..8f1f39bc0f 100644
--- a/quantum/dynamic_keymap.c
+++ b/quantum/dynamic_keymap.c
@@ -29,24 +29,22 @@
 #    define DYNAMIC_KEYMAP_MACRO_COUNT 16
 #endif
 
-// This is the default EEPROM max address to use for dynamic keymaps.
-// The default is the ATmega32u4 EEPROM max address.
-// Explicitly override it if the keyboard uses a microcontroller with
-// more EEPROM *and* it makes sense to increase it.
+#ifndef TOTAL_EEPROM_BYTE_COUNT
+#    error Unknown total EEPROM size. Cannot derive maximum for dynamic keymaps.
+#endif
+
 #ifndef DYNAMIC_KEYMAP_EEPROM_MAX_ADDR
-#    if defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__)
-#        define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 2047
-#    elif defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
-#        define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 4095
-#    elif defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega16U4__) || defined(__AVR_AT90USB162__) || defined(__AVR_ATtiny85__)
-#        define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 511
-#    else
-#        define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR 1023
-#    endif
+#    define DYNAMIC_KEYMAP_EEPROM_MAX_ADDR (TOTAL_EEPROM_BYTE_COUNT - 1)
+#endif
+
+#if DYNAMIC_KEYMAP_EEPROM_MAX_ADDR > (TOTAL_EEPROM_BYTE_COUNT - 1)
+#    pragma message STR(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) " > " STR((TOTAL_EEPROM_BYTE_COUNT - 1))
+#    error DYNAMIC_KEYMAP_EEPROM_MAX_ADDR is configured to use more space than what is available for the selected EEPROM driver
 #endif
 
 // Due to usage of uint16_t check for max 65535
 #if DYNAMIC_KEYMAP_EEPROM_MAX_ADDR > 65535
+#    pragma message STR(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR) " > 65535"
 #    error DYNAMIC_KEYMAP_EEPROM_MAX_ADDR must be less than 65536
 #endif
 
@@ -71,6 +69,7 @@
 // or DYNAMIC_KEYMAP_EEPROM_MAX_ADDR to increase it, *only if* the microcontroller has
 // more than the default.
 #if DYNAMIC_KEYMAP_EEPROM_MAX_ADDR - DYNAMIC_KEYMAP_MACRO_EEPROM_ADDR < 100
+#    pragma message STR(DYNAMIC_KEYMAP_EEPROM_MAX_ADDR - DYNAMIC_KEYMAP_MACRO_EEPROM_ADDR) " < 100"
 #    error Dynamic keymaps are configured to use more EEPROM than is available.
 #endif