While for now this for now only includes helpers for the current limited
display interface which is relatively simple to implement manually, in
the future we will likely need a more complex interface with gpu drivers
that would be hard to get right without a common crate proving the
interface.
This unifies the driver interface handling between graphics drivers and
makes it easier to change all graphics drivers in lockstep when adding
new features.
The daemon responsible for the boot log must never ever block to avoid
deadlocks, but doing so while still accepting keyboard input is
non-trivial. This commit splits the boot log out from fbcond into a
separate daemon to make this a lot easier to implement. This will also
allow making fbcond blocking again, which will simplify some things.
Previously inputd would directly push vt activation events to the
graphics driver, which required being quite lazy to prevent deadlocks as
well as the graphics driver having a location where events can be pushed
to. By having graphics drivers pull the vt activation events instead,
the effective control flow becomes simpler and it becomes easier to
correctly handle multiple graphics drivers on the system. For example it
becomes possible for multiple graphics drivers to present displays for a
single VT as well as making it easier to provide a handoff from the
early framebuffer to a real graphics driver.
This will make it easier to change the way logging is done for all
drivers. This also fixes the log category for a couple of drivers as
well as makes failing to set the logger a fatal error. Only when a
logger is already set is it impossible to set another logger.
Currently pcid exits the main thread once it is done spawning drivers
and expects all background threads handling driver communication to stay
around. This only works as exitting the main thread on redox os
currently doesn't cause the whole process to die. This will have to be
fixed at some point for compatibility with programs that expect that
exitting the main thread kills all other threads in the process, at
which point pcid would break without the changes in this commit.
bjorn3