96
edits
Changes
AGB NAND savegame format, MAC, etc
* Flash V124 was observed 0x90, V131 was observed 0xC0.
* Flash V124 was observed 0x90, V131 was observed 0xC0.
* EEPROM-based games vary wildly, since they can likely specify chip info in the 0x10-region of the footer.
* EEPROM-based games vary wildly, since they can likely specify chip info in the 0x10-region of the footer.
===NAND Savegame===
AGB_FIRM saves its active save memory to NAND on exit, this is then immediately picked up by NATIVE_FIRM on reboot by checking [[CONFIG_Registers#CFG_BOOTENV|CFG_BOOTENV]]. From there, this is verified and copied out to SD. The savegame format is as follows:
{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x0
| 0x4
| Magic ('.SAV')
|-
| 0x4
| 0xC
| Always 0xFF
|-
| 0x10
| 0x10
| AES-MAC of the SHA256 hash of 0x30..0x200 + the entire save itself, keyslot 0x24, keyY from process9 .rodata
|-
| 0x20
| 0x10
| Always 0xFF
|-
|-
| 0x30
| 0x40
| Always 0x1?
|-
| 0x34
| 0x4
| ? (observed 0x1, may change though)
|-
| 0x38
| 0x8
| AGB TitleID
|-
| 0x40
| 0x10
| eMMC CID from the console the save was made on (verified on load)
|-
| 0x50
| 0x4
| Save start addr (always 0x200)
|-
| 0x54
| 0x4
| Save size
|-
| 0x58
| 0x8
| Always 0xFF (?)
|-
| 0x60
| 0x4
| See [[ARM7_Registers|here]]
|-
| 0x64
| 0x4
| See [[ARM7_Registers|here]]
|-
| 0x68
| 0x198
| Always 0xFF
|}