Improve flash operation logging and serialization padding

- Added detailed logging for flash write and erase operations.
- Ensured serialized save data is aligned to 4-byte boundaries.

Software/MainBoard/rust/src/hal/savegame_manager.rs

@@ -2,7 +2,7 @@ use alloc::vec::Vec;
 use bincode::{Decode, Encode};
 use embedded_savegame::storage::{Flash, Storage};
 use embedded_storage::nor_flash::{NorFlash, ReadNorFlash};
-use esp_bootloader_esp_idf::partitions::{Error as PartitionError, FlashRegion};
+use esp_bootloader_esp_idf::partitions::{Error as PartitionError, Error, FlashRegion};
 use log::{error, info};
 use serde::Serialize;
 
@@ -58,7 +58,16 @@ impl Flash for SavegameFlashAdapter<'_> {
     }
 
     fn write(&mut self, addr: u32, data: &mut [u8]) -> Result<(), Self::Error> {
-        NorFlash::write(self.region, addr, data).map_err(SavegameFlashError)
+        info!(
+            "Relative writing to flash at 0x{:x} with length {}",
+            addr,
+            data.len()
+        );
+        let error = NorFlash::write(self.region, addr, data);
+        if error.is_err() {
+            error!("error {:?}", error.unwrap_err())
+        }
+        error.map_err(SavegameFlashError)
     }
 
     /// Erase one full slot at `addr`.
@@ -74,6 +83,11 @@ impl Flash for SavegameFlashAdapter<'_> {
         let end = addr + SAVEGAME_SLOT_SIZE as u32;
         let aligned_end = end.div_ceil(ERASE_SIZE) * ERASE_SIZE;
 
+        info!(
+            "Relative erasing flash at 0x{:x} (aligned to 0x{:x}-0x{:x})",
+            addr, aligned_start, aligned_end
+        );
+
         if aligned_start != addr || aligned_end != end {
             log::warn!("Flash erase address not aligned: addr=0x{:x}, slot_size=0x{:x}. Aligned to 0x{:x}-0x{:x}", addr, SAVEGAME_SLOT_SIZE, aligned_start, aligned_end);
         }
@@ -125,7 +139,14 @@ impl SavegameManager {
             data: data.to_vec(),
         };
         let mut serialized = bincode::encode_to_vec(&wrapper, bincode::config::standard())?;
-        info!("Serialized config with size {}", serialized.len());
+
+        // Flash storage often requires length to be a multiple of 4.
+        let padding = (4 - (serialized.len() % 4)) % 4;
+        if padding > 0 {
+            serialized.extend_from_slice(&[0u8; 4][..padding]);
+        }
+
+        info!("Serialized config with size {} (padded)", serialized.len());
         self.storage.append(&mut serialized)?;
         Ok(())
     }