From 3dbrew
Jump to navigation Jump to search

The following is a list of mysteries.


  • What is the CTR abbreviation?
C may stand for Chiheisen ("horizon" in Japanese, the O3DS's codename being "Project Horizon").
Not true, Horizon refers to the OS.
CTR stands for Citrus.


Why are there two CTRCARD controllers?[edit]

Background: Also DSi SoC pinout shows evidence of dual NTRCARD controllers on the final DSi SoC. (This was a planned feature of the DSi before being axed later in development)

Why are there two EMMC controllers?[edit]

Theory: At some point during 3DS hardware development there was an idea to split up CTR and TWL nand into two different chips.

Is there a JTAG?[edit]

Is there more than one revision of the bootrom?[edit]

Background: Bootrom visible portion has been dumped on the entire 3DS Family (3DS, 3DSXL, 2DS, New3DS, New3DSXL, New2DSXL), and even a prototype board from April(?) 2010. All matching exactly.

What is the EMMC controller @ 0x10100000 doing?[edit]

Background: There's dead code in NWM referencing it.

Why did they put NTRCARD accessible from ARM11?[edit]

Theory: At some point during 3DS hardware development there was a concept where ARM11 ran a menu with DS(i) icons while ARM9 was in TWL mode.

Is there a secret message embedded in the 3DS keyscrambler constant?[edit]

Background: TWL key scrambler constant was "Nintendo Co., Ltd" in Japanese ("任天堂株式会社"), UTF-16LE encoded, with byte order mark. The 3DS key scrambler constant, by comparison, is random-looking.

What is the PDN abbreviation?[edit]


How does Nintendo reflash bricked systems?[edit]

Before trying to boot from NAND, the bootrom checks to see if a key combination (Start + Select + X) is being held, and whether the shell is closed. If so, it tries to boot from an inserted NTR (Nintendo DS) cartridge. This allows to execute a FIRM that is probably used by Nintendo to reflash the system.


What was the problem in "initial program loader" that was mentioned in an FCC filing by Nintendo for 2DS?[edit]


This could be referring to the ROM on the AR6K wireless chip:

  • Some 2DS units have the WiFi chip soldered directly to the board (such as the 2DS in this FCC filing:, and some do not.
  • The AR6K ROM only acts as an initial loader.
  • Maybe some AR6K-family devices allow signature checks on the firmware? Or maybe some registers weren't write-once but should have been?

What did SVC 0x74 in the ARM11 kernel do before it got stubbed?[edit]

What is the PTM abbreviation?[edit]

PlayTime Management

Why is the DTCM not used anywhere except bootrom?[edit]

Background: Bootrom is known to use part of DTCM as state, memsetting it to 0 when it's done. After that, it is never used again.

How is CTRAging launched during factory setup?[edit]

Background: No TestMenu version is capable of launching CTRAging directly: O3DS factory TestMenu can only launch DevMenu installed on NAND, the inserted cartridge and the TWL/AGB test apps; N3DS factory TestMenu can only launch DevMenu installed on NAND, the inserted cartridge and System Settings.

Theory: NtrBoot another time

Why are there 4 stubbed syscalls named SendSyncRequest1-4?[edit]

Is there a deterministic formula for calculating the Movable.sed KeyY high u64?[edit]

Background: We know now that the high 4 bytes of KeyY can be reliably estimated to be 1/5th of the LocalFriendCodeSeed (low 8 bytes of KeyY), which is close enough to brute force. However, the actual value is usually about 0-4000 units off the actual high u32 of the KeyY (called msed3 in the seedminer implementation). Could there possibly be a deterministic formula given this 1/5 ratio is so close to the correct value? It's difficult to imagine this is just a coincidence.