A pull request was opened earlier in the original MCUBoot repository (https://github.com/JuulLabs-OSS/mcuboot/pull/369).
Port the multi-image boot feature from the original MCUBoot repository. This task involves the following steps:
- Sync MCUBoot code base with the original repository
- Port the already existing commits from the pull request
- Modify the build system to handle multiple firmware images (Secure and Non-secure), e.g. sign them separately, multiple image version numbers and security counter values
- Add support for dependency description (modifications in build system and imgtool script)