For a very long time, the kernel had only support for basic PS/2 devices
such as the PS2 AT keyboard and regular PS2 mouse (with a scroll wheel).
To adapt to this, we had very simple abstractions in place, essentially,
the PS2 devices were registered as IRQ handlers (IRQ 1 and 12), and when
an interrupt was triggered, we simply had to tell the I8042Controller to
fetch a byte for us, then send it back to the appropriate device for
further processing and queueing of either a key event, or a mouse packet
so userspace can do something meaningful about it.
When we added the VMWare mouse integration feature it was easily adapted
to this paradigm, requiring small changes across the handling code for
these devices.
This patch is a major cleanup for any future advancements in the HID
subsystem.
It ensures we do things in a much more sane manner:
- We stop using LockRefPtrs. Currently, after the initialization of the
i8042 controller, we never have to change RefPtrs in that class, as we
simply don't support PS2 hotplugging currently.
Also, we remove the unnecessary getters for keyboard and mouse devices
which also returned a LockRefPtr.
- There's a clear separation between PS2 devices and the actual device
nodes that normally exist in /dev. PS2 devices are not polled, because
when the user uses these devices, they will trigger an IRQ which when
is handled, could produce either a MousePacket or KeyEvent, depending
on the device state.
The separation is crucial for buses that are polled, for example - USB
is a polled bus and will not generate an IRQ for HID devices.
- There's a clear separation in roles of each structure. The PS2 devices
which are attached to a I8042Controller object are managing the device
state, while the generic MouseDevice and KeyboardDevice manage all
related tasks of a CharacterDevice, as well as interpreting scan code
events and mouse relative/absolute coordinates.
It happens to be that only PS/2 devices that are connected via the i8042
controller can generate interrupt events, so it makes much more sense to
have those devices to implement the enable_interrupts method because of
the I8042Device class and not the HIDDevice class.
Use the new class in HID code, because all other HID device controllers
will be using this class as their parent class.
Hence, we no longer keep a reference to any PS/2 device in HIDManagement
and rely on HIDController derived classes to do this for us.
It also means that we removed another instance of a LockRefPtr, which
is designated to be removed and is replaced by the better pattern of
SpinlockProtected<RefPtr<>> instead.
Instead, only update it when the Caps Lock key event is generated and
remapping to the Ctrl key is enabled.
This fixes a bug that when enabling remapping Caps Lock key to the Ctrl
key, the original Ctrl key is no longer usable.
This header has always been fundamentally a Kernel API file. Move it
where it belongs. Include it directly in Kernel files, and make
Userland applications include it via sys/ioctl.h rather than directly.
The setting of scan code set sequence is removed, as it's buggy and
could lead the controller to fail immediately when doing self-test
afterwards. We will restore it when we understand how to do so safely.
Allow the user to determine a preferred detection path with a new kernel
command line argument. The defualt option is to check i8042 presence
with an ACPI check and if necessary - an "aggressive" test to determine
i8042 existence in the system.
Also, keep the i8042 controller pointer on the stack, so don't assign
m_i8042_controller member pointer if it does not exist.
This step would ideally not have been necessary (increases amount of
refactoring and templates necessary, which in turn increases build
times), but it gives us a couple of nice properties:
- SpinlockProtected inside Singleton (a very common combination) can now
obtain any lock rank just via the template parameter. It was not
previously possible to do this with SingletonInstanceCreator magic.
- SpinlockProtected's lock rank is now mandatory; this is the majority
of cases and allows us to see where we're still missing proper ranks.
- The type already informs us what lock rank a lock has, which aids code
readability and (possibly, if gdb cooperates) lock mismatch debugging.
- The rank of a lock can no longer be dynamic, which is not something we
wanted in the first place (or made use of). Locks randomly changing
their rank sounds like a disaster waiting to happen.
- In some places, we might be able to statically check that locks are
taken in the right order (with the right lock rank checking
implementation) as rank information is fully statically known.
This refactoring even more exposes the fact that Mutex has no lock rank
capabilites, which is not fixed here.
The i8042 controller with its attached devices, the PS2 keyboard and
mouse, rely on x86-specific IO instructions to work. Therefore, move
them to the Arch/x86 directory to make it easier to omit the handling
code of these devices.
The AHCI code doesn't rely on x86 IO at all as it only uses memory
mapped IO so we can simply remove the header.
We also simply don't use x86 IO in the Intel graphics driver, so we can
simply remove the include of the x86 IO header there too.
Everything else was a bunch of stale includes to the x86 IO header and
are actually not necessary, so let's remove them to make it easier to
compile non-x86 Kernel builds.
The VMWare backdoor handling code involves many x86-specific
instructions and therefore should be in the Arch/x86 directory. This
ensures we can easily omit the code in compile-time for non-x86 builds.
Many code patterns and hardware procedures rely on reliable delay in the
microseconds granularity, and since they are using such delays which are
valid cases, but should not rely on x86 specific code, we allow to
determine in compile time the proper platform-specific code to use to
invoke such delays.
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:
- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable
This patch renames the Kernel classes so that they can coexist with
the original AK classes:
- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable
The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
Instead of having two separate implementations of AK::RefCounted, one
for userspace and one for kernelspace, there is now RefCounted and
AtomicRefCounted.
All users which relied on the default constructor use a None lock rank
for now. This will make it easier to in the future remove LockRank and
actually annotate the ranks by searching for None.
In most cases it's safe to abort the requested operation and go forward,
however, in some places it's not clear yet how to handle these failures,
therefore, we use the MUST() wrapper to force a kernel panic for now.
On the QEMU microvm machine type, it became apparent that the BIOS was
not setting the i8042 controller to function as expected. To ensure that
the controller is always outputting correct scan codes, set it to scan
code 2 and enable first port translation to ensure all scan codes are
translated to scan code set 1. This is the expected behavior when using
SeaBIOS, but on qboot (the BIOS for the QEMU microvm machine type), the
firmware doesn't take care of this so we need to do this ourselves.
Some error indication was done by returning bool. This was changed to
propagate the error by ErrorOr from the underlying functions. The
returntype of the underlying functions was also changed to propagate the
error.
Some hardware controllers might reset when trying to do self-test, so
keep the configuration byte to restore it later on.
To ensure we are not missing the response from the i8042 controller,
bump the attempts count to 20 times after initiating self-test check.
Also, try to drain the i8042 controller output buffer as it might be a
early good indication on whether i8042 is present or not.
To ensure we drain all the output buffer, we attempt to read from the
buffer 50 times and not 20 times.
This is very similar to the change that was done in 32053e8, except it
turned out that the new limit of 50 iterations was not enough when
testing on bare metal - most IO operations would succeed in the first or
second iteration, but two of them took 140 and 150 iterations
respectively.
Increase the limit from 50 to 250 to account for this, and have some
additional headroom.
This caused an initialization failure of the i8042 when I tested on
bare metal. We cannot entirely get rid of this method as QEMU for
example doesn't indicate the existence of an i8042 via ACPI, but we can
get away with only doing the manual probing if ACPI is disabled or we
didn't get a 'yes' from it.
Increasing the number of maximum loops did eventually lead to a
successful return from the function, but would later fail the actual
self test.
Since we're in an IRQ each of these evaluate_block_conditions() calls
enqueues a new deferred call, so to save on some space in the deferred
call queue let's just do it once.
Apparently on VirtualBox the keyboard device refused to complete the
reset sequence. With longer delays and more attempts before giving up,
it seems like the problem is gone.
Not only does it makes the code more robust and correct as it allows
error propagation, it allows us to enforce timeouts on waiting loops so
we don't hang forever, by waiting for the i8042 controller to respond to
us.
Therefore, it makes the i8042 more resilient against faulty hardware and
bad behaving chipsets out there.
If we don't do so, we just hang forever because we assume there's i8042
controller in the system, which is not a valid assumption for modern PC
hardware.
We currently support the left super key. This poses an issue on
keyboards that only have a right super key, such as my Steelseries 6G.
The implementation mirrors the left/right shift key logic and
effectively considers the right super key identical to the left one.
This was easily done, as the Kernel and Userland don't actually share
any of the APIs exposed by it, so instead the Kernel APIs were moved to
the Kernel, and the Userland APIs stayed in LibKeyboard.
This has multiple advantages:
* The non OOM-fallible String is not longer used for storing the
character map name in the Kernel
* The kernel no longer has to link to the userland LibKeyboard code
* A lot of #ifdef KERNEL cruft can be removed from LibKeyboard
