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mLine 33:
Line 33: + + − First, there are 8 bytes whose purposes are currently unknown. Then comes the actual blockmap.+ − The blockmap structure is simple:+ Line 46:
Line 48: − There's one entry per sector, counting from physical sector 1 (sector 0 contains the blockmap/journal).+ + − Then comes the journal.+ − The journal structure is as follows:+
→Wear leveling
=== Wear leveling ===
=== Wear leveling ===
3DS在游戏存档闪存芯片上引入了wear leveling 方案。这是通过使用blockmap和journal来实现的。blockmap在闪存上偏移量为0，其后是journal。初始状态由blockmap指定，然后journal对其进行应用。
The 3DS employs a wear leveling scheme on the savegame FLASH chips. This is done through the usage of blockmaps and a journal. The blockmap is located at offset 0 of the flash chip, and is immediately followed by the journal. The initial state is dictated by the blockmap, and the journal is then applied to that.
The 3DS employs a wear leveling scheme on the savegame FLASH chips. This is done through the usage of blockmaps and a journal. The blockmap is located at offset 0 of the flash chip, and is immediately followed by the journal. The initial state is dictated by the blockmap, and the journal is then applied to that.
首先，是8字节目前还不明白其确切意义的数据。然后是实际的blockmap。其结构很简单：
<pre>
<pre>
struct header_entry {
struct header_entry {
</pre>
</pre>
每个sector有一个入口，从实际的sector1开始计数（sector 0 包含blockmap/journal）。
blockmap后2字节为最开始的8个字节，以及blockmap的CRC16校验码（开始值为0xFFFF（像modbus））。
The 2 bytes that follow the blockmap are the CRC16 (with starting value 0xFFFF (like modbus)) of the first 8 bytes and the blockmap.
The 2 bytes that follow the blockmap are the CRC16 (with starting value 0xFFFF (like modbus)) of the first 8 bytes and the blockmap.
然后是journal。其结构如下:
<pre>
<pre>
struct sector_entry {
struct sector_entry {