This repository is a bare-metal custom bootloader and graphical recovery environment for the Nintendo Switch (Tegra T210/T210B01). It boots Horizon OS, Linux4Tegra, and third-party payloads by decrypting and patching the encrypted HOS boot chain (package1, package2, package3), deriving console keys from TSEC/EKS data, and applying version-specific binary patches. It also provides emuMMC creation and migration, eMMC and SD card tools, USB gadget modes (mass storage and HID), AutoRCM, fuel gauge/thermal diagnostics, and a full hardware bring-up path including display, touch, Joy-Con input, DRAM training, and power management. The code clearly reflects the bootloader's actual production role: a user-triggered payload running from RCM on real Switch hardware, with a text TUI in the main bootloader and a separate LVGL-based graphical frontend called Nyx. Architecturally, the repo is organized into a hardware abstraction layer called BDK (Board Development Kit), the bootloader core, the Nyx GUI application, and dynamically loadable ELF modules for DRAM training and SDRAM LP0 sleep state. The BDK provides drivers for SoC peripherals, power management ICs, storage controllers, the security engine, USB, input, and display, all written as bare-metal C with direct MMIO register access and no OS dependencies. The bootloader uses an INI-based configuration system, a small graphics console, and a module loader that can load ELF shared objects from SD or eMMC. Nyx is a separate application built on a heavily customized fork of LittlevGL v5, with custom themes, fonts, resource packing, and hardware tools. The code demonstrates strong embedded systems skill: meticulous hardware register definitions, retry and error-counting logic in storage drivers, cryptographic key derivation routines updated through many firmware generations, and carefully structured patch tables for firmware signatures. The main weaknesses are the aging bundled libraries (FatFs and LVGL forks are old and diverged from upstream), duplicated graphics implementations between bootloader and sample module, and a large amount of hardcoded hardware-specific constants and addresses. This is not general-purpose software; it is tightly coupled to Tegra X1 hardware and the Nintendo Switch modding ecosystem, but the BDK driver organization, ELF loader, INI parser, list macros, and compression utilities are genuinely reusable in other low-level projects.