We use a "fake signature" to sign the modules. As far as kmod is
concerned the signature fields are informational only. It's the kernel
the responsible for checking it's valid.
So what we are doing here is: pick the signatures of the ext4-x86_64.ko
module and save as dummy.{hashalgo}. This signature is appended to the
mod-simple.ko module so the ext4-x86_64.ko module can be removed from
tree.
This is for convenience for development and testing since we don't want
to needlessly cross-compile the modules. There's a README file
explaining the building process for those who want to update them.
These files are compiled from their respective .c and thus have LPGL
license.
This adds the needed infra to cross-compile modules so we can test them
in our testsuite. Right now we are only compiling mod-simple.ko for x86,
x86_64 and sparc64.
The makefiles are organized in a way it's easy to force a rebuild of a
module by calling the Makefile.arch directly and that allows the rule in
Makefile to not trigger in case we want to ship the modules
pre-compiled.
Instead of shipping pre-compiled module, this prepares the build system
to be able to compile the necessary modules from module-playground. This
preparations starts by replacing md5.ko with our own dummy
mod-simple.ko, built from source. It works by copying the modules to
their final location while preparing the rootfs.
