Various sub-projects around the UHD repository specify their own minimum
CMake versions (independent of UHD). We modify the minimum CMake
versions in the following way:
- All CMake files under firmware/ are bumped from 2.6 to 3.5. This is to
allow newer CMake versions to work with these files (CMake 4 and
beyond do no longer work if the minimum version is below 3.5). However,
note that these CMake files are so simple they will keep working with
older CMake versions, but that will require manually demoting the
minimum version. Because more people are using CMake versions newer
than 3.5 (especially with recent checkouts of UHD), this seems the
more compatible solution.
- The CMake files for extension_example and init_usrp are bumped to
3.12. This matches the version that UHD uses, which increases
compatibility.
