The following is a list of mysteries.

General

  • What is the CTR abbreviation?
C may stand for Chiheisen ("horizon" in Japanese, the O3DS's codename being "Project Horizon").

Hardware

Why are there two CTRCARD controllers?

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?

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?

Is there more than one revision of the bootrom?

Background: Bootrom visible portion has been dumped on 3DS, 3DSXL, 2DS, New3DS. All matching exactly.

What is the EMMC controller @ 0x10100000 doing?

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

Why did they put NTRCARD accessible from ARM11?

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?

Background: TWL keyscrambler constant was Nintendo in Japanese, utf-8 encoded.

Software

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

Background: http://www.neogaf.com/forum/showthread.php?t=814624&page=1

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

What is the PTM abbreviation?

What is the PDN abbreviation?

Why is the DTCM not used anywhere except bootrom?

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.