v1.15.0

This is a major update to Buildroot 2021.02. Please review the Buildroot release
notification below in addition to the following. The following changes affect
all systems:

1. The rngd daemon's jitter entropy option changed defaults. This daemon feeds
   values from a hardware random number generator to the Linux kernel's entropy
   pool. Without it, you can experience long boot delays as programs wait for
   enough entropy to get good random numbers. Jitter entropy is a way of
   gathering entropy from the CPU without any special random number generation
   hardware. It's not necessary with most hardware with Nerves and it adds a
   boot-time delay as the CPU is measured. Previously Nerves defaulted it to off, but
   now it is consistent with Buildroot's default. To retain the previous behavior,
   you need to add the following to your nerves_defconfig:

   # BR2_PACKAGE_RNG_TOOLS_JITTERENTROPY_LIBRARY is not set
   

2. Buildroot changed how it computes hashes over projects downloaded from
   version control systems. If you have made a custom system and added your own
   packages, you may need to update the .hash files to -br1 versions. The
   files are different so the existing checksums will not match. See buildroot
   5b95a5d
   for more info.

3. The nervesproject/nerves_system_br Docker image that corresponds to this
   release has been updated from Ubunto 18.04 LTS to Ubuntu 20.04 LTS. This
   fixed an internal compiler error that was seen, but resulted in some package
   changes (no more Python 2, for example) that might affect scripts using it.

• Improvements

  • It's now possible to include executable files for other CPU architectures in
    the root filesystem without have the scrubber find them and report an error.
    To use this feature, add the file .noscrub to the directory with the files.

• Package updates

  • Buildroot 2021.02
  • Erlang/OTP 23.2.7