[MERGE] Non-Volatile memory data repository pattern (24356)

quantum/nvm/eeprom/nvm_eeprom_via_internal.h

@@ -0,0 +1,22 @@
+// Copyright 2024 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#pragma once
+
+// Keyboard level code can change where VIA stores the magic.
+// The magic is the build date YYMMDD encoded as BCD in 3 bytes,
+// thus installing firmware built on a different date to the one
+// already installed can be detected and the EEPROM data is reset.
+// The only reason this is important is in case EEPROM usage changes
+// and the EEPROM was not explicitly reset by bootmagic lite.
+#ifndef VIA_EEPROM_MAGIC_ADDR
+#    define VIA_EEPROM_MAGIC_ADDR (EECONFIG_SIZE)
+#endif
+
+#define VIA_EEPROM_LAYOUT_OPTIONS_ADDR (VIA_EEPROM_MAGIC_ADDR + 3)
+
+// The end of the EEPROM memory used by VIA
+// By default, dynamic keymaps will start at this if there is no
+// custom config
+#define VIA_EEPROM_CUSTOM_CONFIG_ADDR (VIA_EEPROM_LAYOUT_OPTIONS_ADDR + VIA_EEPROM_LAYOUT_OPTIONS_SIZE)
+
+#define VIA_EEPROM_CONFIG_END (VIA_EEPROM_CUSTOM_CONFIG_ADDR + VIA_EEPROM_CUSTOM_CONFIG_SIZE)