Crate embedded_savegame 

Overview

This library provides a power-fail safe savegame system for embedded devices with wear leveling. It manages data storage on flash memory (EEPROM or NOR flash) by distributing writes across multiple slots to prevent wear-out of specific memory locations.

Flash Support

• eeprom24x feature: Support for AT24Cxx EEPROM chips
• w25q feature: Support for W25Q NOR flash chips
• mock feature: Mock flash implementations for testing

Example

use embedded_savegame::storage::{Storage, Flash};

// Configure storage with 64-byte slots across 8 total slots
const SLOT_SIZE: usize = 64;
const SLOT_COUNT: usize = 8;

let mut storage = Storage::<_, SLOT_SIZE, SLOT_COUNT>::new(flash_device);

// Scan for existing savegame
if let Some(slot) = storage.scan()? {
    let mut buf = [0u8; 256];
    if let Some(data) = storage.read(slot.idx, &mut buf)? {
        // Process loaded savegame
    }
}

// Write new savegame
let mut save_data = b"game state data".to_vec();
storage.append(&mut save_data)?;

Architecture

Each slot contains a header with:

• Current savegame checksum
• Data length
• Previous savegame checksum (for chain verification)

The scanner finds the most recent valid savegame by following the checksum chain.

Modules

chksum

Checksum implementation for savegame validation

eeprom24x

AT24Cxx EEPROM support

mock

Mock flash implementations for testing

storage

Flash storage abstraction and savegame management

Structs

Slot

A savegame slot containing metadata about stored data