We’ve recently provided software support to Analogue & Micro who are developing hardware derived from NXP’s Layerscape FRWY-LS1012A reference design. What we find interesting about this reference design is that for storage it uses an innovative SPI memory known as SpiStack Flash. Essentially it’s a single chip with a quad-SPI interface, but inside are two …
Category: UBoot
Flattened uImage Tree (FIT) Images
You’re probably familiar with the steps required to boot Linux from U-Boot: you first load several binaries into memory, perhaps a device tree, a kernel, maybe even an initrd. You then invoke a command such as bootm or booti with arguments providing memory addresses for the binaries you’ve just loaded. However there is a much …
Power-failure-tolerant bootloader flashing on eMMC
It’s a widely held misconception that flashing a bootloader on a device in the field is risky. The reason is that if power is removed from the device during update, then the bootloader may only be partially flashed and thus won’t boot. This view is correct for devices that boot from a single location without …
A Global Variable in U-Boot that caused a Hang
The best type of software bug is one where you get to learn something along the way. Like any good disaster, the bug we’re going to explore is one that arose from a chain of unexpected events and bad assumptions. This bug relates to uninitialised data and gives a good insight into the inner workings …