Ahead of mainline

The Deinde Concept Tree is where a number of firmware features are developed ahead of mainline U‑Boot. The items below are currently only in the Concept Tree — they have not yet landed in mainline. The hope is that much of this work will make its way upstream over time; for now, this page tracks what is still exclusive to the tree.

EFI application

A full U-Boot EFI app — on x86, ARM and RISC-V

Mainline U‑Boot has only a primitive, x86‑only EFI app. The Concept Tree has a full-featured EFI application: it runs on x86, ARM and RISC‑V, drives video output and keyboard/mouse input, and can boot an operating system (including under a Shim environment). details »

Storage & filesystems

A new filesystem layer

A driver-model layer for files and directories (fs, file and dir uclasses) that the filesystems below build on. details »

ext4l — a fresh ext4 from Linux

A new ext4 implementation ported directly from the Linux kernel, for more robust handling of real-world filesystems. details »

virtio-fs

Mount a directory shared from the host straight into U‑Boot over virtio — handy for emulation and development. details »

LUKS disk encryption

Unlock LUKS1 and LUKSv2 partitions (including AES‑XTS) to boot from encrypted storage. details »

TKey full-disk encryption

Use a Tillitis TKey hardware security key to unlock an encrypted disk at boot. details »

Booting & UI

bootctl — a new boot UI

An interactive boot controller built on standard boot, with an on-screen, mouse-aware menu. details »

Mouse & pointer support

A mouse uclass with USB, EFI and sandbox drivers, plus an on-screen pointer — usable in the boot menu and the EFI app. details »

Booting improvements

Boot Loader Spec (BLS) bootmeth

Boot using the Boot Loader Specification (Type #1), with FIT and multi-initrd support. It scans every partition, so U‑Boot can boot things like Ubuntu live ISOs and autoinstall directly. details »

FEL bootmeth (sunxi)

A standard-boot bootmeth that boots an Allwinner (sunxi) board over the USB FEL protocol. details »

Expo-based environment editing

editenv -e edits an environment variable interactively with an on-screen expo, instead of a plain text prompt. details »

PXE / extlinux parser refactor

The PXE/extlinux parser is split into separate load and setup phases with a clean three-phase API (and memory-leak fixes), plus a standalone parser module. details »

Boot-flow refactoring

Ongoing cleanup of the boot path: FIT printing moved to its own file, the final pre-boot steps factored into one function, and reduced reliance on CMDLINE and kernel_addr_r. details »

Running U-Boot beyond the board

ulib — U-Boot as a library

Build U‑Boot as a shared library and call it from your own programs — in C or Rust. details »

Emulation & testing

A virtio emulator for sandbox

A fully-functional virtio emulator so virtio devices (block, virtio‑fs) can be developed and tested with no hardware — part of broader QEMU/QFW emulation improvements. details »

Developer tools

Console pager

Page through long command output instead of watching it scroll off the top of the screen. details »

Heap debugging

A refreshed dlmalloc (2.8.6) plus heap-debugging commands and mcheck caller tracking for hunting memory bugs. details »

backtrace

Produce a runtime backtrace on demand to help debug what U‑Boot is doing. details »

codman

A source-code analysis tool for tracking and categorising the codebase. details »

This list is derived from the tree’s merge requests and verified against mainline U‑Boot (each feature’s source files are checked against u‑boot/master and u‑boot/next). See also the Upstream status dashboard. Last reviewed 15 September 2026.