Tag: bootloader

  • U-Boot: protect sensitive environment variables

    U-Boot: protect sensitive environment variables

    This is a follow-up from our Accessing the U-Boot environment from a C program blog post. 🌳Need to protect the environment When you’re trying to harden an embedded Linux device to make it more resistant to attacks, one key part to secure is the bootloader, because that’s the part that boots the operating system. Even…

  • See how U-Boot modifies your board device tree

    See how U-Boot modifies your board device tree

    If you compare the device tree as loaded by Linux, available in /sys/firmware/fdt, you will see that it differs from the one that you loaded in U-Boot. Taking the time to make the comparison is quite instructive. Let’s do this on my Toradex Verdin iMX8M Mini SoM on the Dahlia carrier board. Decompiling the DTB…