Homebrew Dictionary

This page aims to detail as many terminologies used within the Nintendo Homebrew community as in-depth as possible.

General

This section defines common terms that either used industry-wide, or for two or more consoles.

BootROM

This is an initial program loader whose primary usecase commonly initialises a device's hardware and prepare it for loading an operating system. It is also typically responsible for authenticating any hardware and software, to ensure that an unauthorised actor isn't able to obtain critical device secrets, and that the device doesn't otherwise run unauthorised code. A bootROM is a ROM, meaning that it is etched into the device and cannot be rewritten or upgraded without replacing the hardware entirely. See ROM.

Bootloader

This performs similar tasks to a bootROM, but is typically on rewritable storage. A bootROM generally does the bare minimum for device maintenance, while a bootloader is often relied on for variable tasks (as a bootloader can be upgraded, in contrast to a bootROM).

Custom Firmware

Referred to as CFW for short, within console modification communities, this is a collection of patches which partially or largely modify the functionality of the underlying OS. It is not used to refer to the usage of brand new operating systems entirely.

emuNAND

In console hacking, this refers to an reimplementation of the system software running solely off of a secondary storage device. In practice, this is always an SD card. On the Switch, this implementation is referred to as emuMMC. The purpose of an emuNAND is to give you a safe place to use custom firmware functions. As the system software on the internal storage is untouched, normal functionality will be wholly unchanged; giving an opportunity for custom firmware and factory functionality to coexist.

NAND

NAND is referred to as "Internal Storage" within Nintendo's consoles, and is the non-volatile storage that the console saves the system software and internal settings to. The name refers to the type of logic gate employed, known as "not-AND" in this case.

Horizon, HOS, or HorizonNX

These all refer to the dedicated operating systems for Nintendo 3DS or Nintendo Switch. HorizonNX references the Switch's codename, so it refers only to the Switch OS.

OS

OS stands for operating system. This is the system software, such as Android, iOS, Windows, or Horizon as examples. It is a collection of software on a device meant to carry out various tasks. This is sometimes referred to as firmware, which is slightly erroneous.

ROM

Read-only memory. This describes any form of semi-permanent or permanent non-volatile storage that cannot be rewritten. Some forms of ROM can be rewritten under very specific scenarios, such as EEPROM (electronically-erasable/programmable ROM).

Stock

A console running in a normal context, without any unauthorised modifications (via software or hardware) is considered to be running as stock. Depending on context, this may also be known as OFW (original firmware).

Nintendo Switch

Software

Atmosphère

Atmosphère is the primary custom firmware for Nintendo Switch. It also fully reimplements many aspects of Horizon from the ground up, unlike other CFW projects, which tend to be limited to hot-patching the underlaying OS. GitHub

AutoRCM

This refers to an environment where the Switch boots into RCM automatically, without the need of a jig.

This can result from corrupted/missing boot sectors, a button combination, or triggered via software.

Qlaunch

This is similar to the HOME Menu on the Nintendo 3DS. It serves as a launcher for many applets such as System Settings, the main home menu (ResidentMenu), User/Friends Page (myPage), Lock Screen (Entrance), News menu (Notification), and so on.

Hardware

Better-battery Switch, redbox Switch, and V2 Switch

These all refer specifically to the full-size Switch that was advertised with better battery - with the product code of HAC-001(-01).

Erista, or T210, and V1

This refer to the original chipset used on all Switch consoles manufactured before mid-2018, before the better-battery Switch.

Please see this hardware table for more info regarding Switch console revisions.

Iowa

This is the codename of the "better battery"/Mariko red-boxed Switch.

Icosa

This is the codename of the original 2017-2019 release of the Switch.

Mariko, or T214, and V2

These refer to the chipset used on any console made after late 2019. This includes Switch Lite, Switch (OLED Model), and the better-battery Switch. Units using Mariko chipsets are unhackable via software for the foreseeable future.

fusee

This references fusee-gelee. It may also casually refer to tools or software that work alongside fusee-gelee's environment, like the fusee.bin payload used for Atmosphère.

Patched

This usually refers specifically to being patched against fusee-gelee. Although it's exceedingly rare, there may be other methods of getting into custom firmware on certain patched units.

RCM

This refers to Nvidia's Recovery Mode. This is where numerous Nvidia errors led to the discovery of fusee, thereby leading to custom firmware on the Switch.

It is important to remember that RCM is an intentional feature of the Tegra X1 and all Switch consoles. Devices have no indication of being in RCM unless the device is plugged into a PC, where it will be listed as an APX device.

Tegra X1

This refers to any version of the main processor used in the Nintendo Switch.

Alternatively, "Tegra" sometimes refers to any toolkit or diagnostic software that runs for processors in the Tegra processor family.

Please see this hardware table for more info regarding Tegra X1 revisions.