The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
If a file is specified in loader_conf_files that ends in '.lua', lualoader
will now load and execute that file. These may be used in place of a
traditional loader.conf to use more complicated logic, where some values
may be set based on others or based on the environment that the C bits has
left us with.
Lua scripts are run in a limited environment. In particular, it does not get
access to any modules or, in-fact, anything except environment variable.
A config.buildenv hook has been added so that a local module can add
whatever it may need to to the environment.
When a global var is set in the lua script, it does not immediately alter
the loader environment. Instead, the script's environment is initially
empty and processed only if the whole script executes successfully.
Effectively, a lua configuration file either takes effect or it does not,
an error will not leave it in a half-baked state.
Reviewed by: bcr (manpages), imp
Differential Revision: https://reviews.freebsd.org/D28450
See: comments in the hook module about intended usage, as well as the
introduced use for config.reloaded.
Use the newly introduced hook module to define a "config.reloaded" hook.
This is currently used to register core's clearKernelCache as a reload hook
to avoid a circular dependency and fix this functionality- it didn't
actually work out, and it isn't immediately obvious how it slipped into src.
Other hook types will be introduced into the core lualoader as useful hook
points are identified.
