U-Boot has long supported extlinux-style boot configurations, but there is another widely-used standard for describing boot entries: the Boot Loader Specification (BLS). Fedora, RHEL and other distributions use BLS Type #1 entries to describe available kernels and their parameters. With this series, U-Boot gains native support for discovering and booting from these entries. Why BLS? The extlinux format…
U-Boot’s codman tool helps developers understand which source files and lines of code are actually compiled into a build. With the latest update, codman gains a powerful new capability: categorising source files by functional area and exporting analysis results to CSV for spreadsheet analysis. The Challenge U-Boot is a massive codebase with over 45,000 source files. When…
A recent series in Concept enables ext4l for an ARM board, finally allowing us to make a concrete comparison between the code size of this new Linux-ported driver and the existing U-Boot implementation. Here is a short note on what we found. The “Linux is Large” Reality The first observation is that the Linux kernel…
This final series in Concept closes out the complete implementation of TKey hardware-backed full disk encryption (FDE) in U-Boot. The previous series established the core logic and UI flow. This final work wraps up the effort by providing end-to-end testing, a useful Python tool for key management on the host, along with documentation, making the…
A new series in Concept introduces the complete logic and UI enhancements required to use a TKey to unlock an encrypted disk (like a LUKS partition) before booting an operating system. 1. The TKey Unlock Flow The TKey unlock process is complex because it involves iterative communication with the external hardware and handling scenarios like…
Debugging embedded bootloaders can often feel like working in the dark. When execution crashes or behaves unexpectedly, the first question an engineer usually asks is, “How did I get here?” Of course, one should always have a JTAG debugger ready to press into service, but so few boards provide a JTAG header. To help, a…
We’re excited to announce that U-Boot concept has merged support for unlocking LUKSv2 encrypted partitions! This is a significant enhancement to U-Boot’s security capabilities, allowing it to handle the encryption standard used today by most current Linux distributions. This 16-patch series (and a small follow-up) bring U-Boot up to speed with modern disk encryption, building…
A new 24-patch series in Concept that introduces basic support for unlocking LUKS1 encrypted partitions directly within U-Boot. This is a foundational step toward a more integrated and user-friendly full-disk encryption (FDE) experience. 🤔 The Problem with “Late” Unlocking Traditionally, FDE on Linux systems is handled late in the boot process. U-Boot loads a kernel…
The build-qemu script provides lots of useful features and is an easy way to run U-Boot under QEMU with an OS, with or without video, etc. Now in Concept it is possible to pass a boot command! The -b/–bootcmd option creates a special ‘file’ within QEMU that contains the requested command. Then U-Boot uses an…
U-Boot Concept now has preliminary support for the ACPI Firmware Performance Data Table (FPDT). It is included in the ‘bootstage and script enhancement’ series. The OS can look at this table to figure out how long the firmware took to boot. Only the ‘basic boot’ record is supported. It contains the following fields: All timestamps…
