From e65162249db5f880edc9d2ac2e18e4c5ddd6653d Mon Sep 17 00:00:00 2001
From: rhetenor <rhetenor@rhetenor.de>
Date: Sat, 29 Aug 2026 14:43:15 +0000
Subject: [PATCH] fix flash initialization by erasing flash before writing

---
 src/storage/cardstore.rs |  4 ++--
 src/storage/store.rs     | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/storage/cardstore.rs b/src/storage/cardstore.rs
index db4fe20..44ff686 100644
--- a/src/storage/cardstore.rs
+++ b/src/storage/cardstore.rs
@@ -183,7 +183,7 @@ impl CardStore {
             log::debug!("writing RawCard to flash");
             let mut serialized_card: [u8; RawCard::SERIALIZED_SIZE] = [0; RawCard::SERIALIZED_SIZE];
             raw_card.binary_serialize(&mut serialized_card, Endianness::Little);
-            self.store.write(
+            self.store.write_erase(
                 CARDS_REGION.offset + entry.offset * RawCard::SERIALIZED_SIZE as u32,
                 &mut serialized_card,
             )?;
@@ -198,7 +198,7 @@ impl CardStore {
         let mut serialized_entry: [u8; AllocationTableEntry::SERIALIZED_SIZE] =
             [0; AllocationTableEntry::SERIALIZED_SIZE];
         entry.binary_serialize(&mut serialized_entry, Endianness::Little);
-        self.store.write(
+        self.store.write_erase(
             ALLOCATION_TABLE_REGION.offset
                 + entry.offset * AllocationTableEntry::SERIALIZED_SIZE as u32,
             &mut serialized_entry,
diff --git a/src/storage/store.rs b/src/storage/store.rs
index c9702db..42f18bf 100644
--- a/src/storage/store.rs
+++ b/src/storage/store.rs
@@ -3,13 +3,12 @@ use embedded_storage::nor_flash::ReadNorFlash;
 use esp_storage::{FlashStorage, FlashStorageError};
 
 use crate::storage::MAGIC_REGION;
-use crate::storage::cardstore::COUNT_REGION;
 
 pub type StoreError = FlashStorageError;
 
 const FLASH_ADDR: u32 = 0x9000;
 
-const INITIALIZATION_SIZE: usize = COUNT_REGION.end();
+const INITIALIZATION_SIZE: usize = 0x1000;
 const FLASH_INITIALIZE_MAGIC: u32 = 0xde6de6de;
 
 pub struct Store {
@@ -43,7 +42,17 @@ impl Store {
         self.storage.write(FLASH_ADDR + offset, bytes)
     }
 
-    fn has_magic_bytes(storage: &mut FlashStorage) -> Result<bool, StoreError> {
+    pub fn write_erase(&mut self, offset: u32, bytes: &mut [u8]) -> Result<(), StoreError> {
+        log::debug!(
+            "Erasing and Writing {} bytes at offset 0x{offset:08x}",
+            bytes.len()
+        );
+        self.storage
+            .erase(FLASH_ADDR + offset, FLASH_ADDR + bytes.len() as u32)?;
+        self.storage.write(FLASH_ADDR + offset, bytes)
+    }
+
+    pub fn has_magic_bytes(storage: &mut FlashStorage) -> Result<bool, StoreError> {
         let mut magic: [u8; 4] = [0, 0, 0, 0];
         storage.read(FLASH_ADDR + MAGIC_REGION.offset, &mut magic)?;
         log::debug!("Magic bytes are {magic:?}");
@@ -51,9 +60,10 @@ impl Store {
         Ok(u32::from_ne_bytes(magic) == FLASH_INITIALIZE_MAGIC)
     }
 
-    fn initialize_flash(storage: &mut FlashStorage) -> Result<(), StoreError> {
+    pub fn initialize_flash(storage: &mut FlashStorage) -> Result<(), StoreError> {
+        storage.erase(FLASH_ADDR, FLASH_ADDR + INITIALIZATION_SIZE as u32)?;
         let zeros: [u8; INITIALIZATION_SIZE] = [0; INITIALIZATION_SIZE];
-        storage.write(FLASH_ADDR, &zeros)?;
+        storage.write(FLASH_ADDR + MAGIC_REGION.end() as u32, &zeros)?;
         storage.write(
             FLASH_ADDR + MAGIC_REGION.offset,
             &FLASH_INITIALIZE_MAGIC.to_ne_bytes(),