In the world of bootloaders, balance is everything. We need enough functionality to load an OS, but we must keep the footprint small and the code maintainable. For years, U-Boot has relied on a custom implementation of the EXT4 filesystem. However, as the EXT4 format evolves with features like metadata checksums and fast commits, keeping…
A new series just landed, focussed on making one part of U-Boot’s new graphical menus (Expo) considerably better with non-popup menus. A long-standing and annoying limitation in expo is that couldn’t really type into text fields (like for passwords) if the menu wasn’t a pop-up (i.e. as used by the ‘cedit’ configuration editor). Now, with…
Expo is U-Boot’s forms and UI subsystem. It supports text, images and menus and a large expo can contain quite a bit of information. How do you debug and understand that? Tracing through large, linked data structures is not fun. U-Boot Concept now has an expo_dump() function, designed to be called from your code when…
Testing boot scenarios in very important but there are quite a lot of them! Concept currently has about 13 images containing various partitions and files used by the bootstd tests. These are listed in test.dts, for example: All images are built by test_ut_dm_init_bootstd(), but most of these are disabled by default, to avoid making sandbox…
U-Boot’s ‘expo’ toolkit is used for creating user interfaces, such as the configuration editor (cedit) and graphical boot menus (bootflow menu). Previously, user interaction with expo scenes was limited to the keyboard. A recent 23-patch series introduces support for mouse and touchpad interaction. New Input Handling For devices where a mouse or touchpad is available,…
The U-Boot EFI application is a powerful tool, allowing U-Boot to run on top of existing UEFI firmware. This is increasingly important as we see new platforms, especially in the ARM64 world, shipping with complex, ACPI-based firmware. A prime example is the recent wave of laptops powered by the Qualcomm X-Elite, which rely on this…
If you are interested in watching the development of U-Boot Concept, consider joining the mailing list. You can do this in your web browser here, or send an email with ‘subscribe’ in the subject to concept-join@u-boot.org. If you are able to review patches or contribute your own, please do! Also the patchwork server is up and…
We’ve just merged a fix in Concept for a particularly tricky memory corruption bug in the U-Boot sandbox environment. This bug was difficult to track down, so we wanted to share the story of the investigation and the solution. The Symptom: Mysterious Heap Corruption The problem first appeared as random and hard-to-reproduce memory corruption in…
Continuous Integration (CI) is the backbone of a large project like U-Boot, ensuring that every change is tested against a huge matrix of boards and configurations. While this comprehensive testing is vital for quality, it can also be time-consuming. When you’re focused on a specific feature, waiting for a full “world build” to complete can…
As U-Boot’s support for hardware grows, so does the complexity of managing build configurations. A single board might require several build variations—for example, one with network support and one without, or a standard build versus one tailored for Android booting. Historically, managing these variations often meant duplicating large defconfig files, a maintenance headache waiting to…
