Keyboard drivers are generally registered via linker set. In these cases,
they're also available as kmods which use KPI for registering/unregistering
keyboard drivers outside of the linker set.
For built-in modules, we still fire off MOD_LOAD and maybe even MOD_UNLOAD
if an error occurs, leading to registration via linker set and at MOD_LOAD
time.
This is a minor optimization at best, but it keeps the internal kbd driver
tidy as a future change will merge the linker set driver list into its
internal keyboard_drivers list via SYSINIT and simplify driver lookup by
removing the need to consult the linker set.
Most keyboard drivers are using the genkbd implementations as it is;
formally use them for any that aren't set and make
genkbd_get_fkeystr/genkbd_diag private.
A future change will provide default implementations for some of these where
it makes sense and most of them are already using the genkbd
implementation (e.g. get_fkeystr, diag).
These invocations were directly calling enkbd_diag(), rather than
indirection back through kbdd_diag/kbdsw. While they're functionally
equivent, invoking kbdd_diag where feasible (i.e. not in a diag
implementation) makes it easier to visually identify locking needs in these
other drivers.
Synthetic keyboard is the only supported keyboard on GEN2 Hyper-V.
Submitted by: Hongjiang Zhang <honzhan microsoft com>
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D10196
