These are not technically required, since the Thread constructor
already sets these, but they are set on i686, so let's try and keep
consistent behaviour between the different archs.
The Qemu AC'97 device stops its PCM channel's DMA engine when it is
running and the sample rate is changed. We now make sure the DMA engine
is restarted after changing the sample rate, allowing you to e.g. run
`asctl set r 22050` during `aplay` playback.
In short: QEMU supports both Memory-Mapped-IO and classic IO methods
for controlling the emulated VGA device. Bochs and VirtualBox only
support the classic IO method. An excellent write up on the history of
these interfaces can be found here:
https://www.kraxel.org/blog/2018/10/qemu-vga-emulation-and-bochs-display
The IO method was how things were done originally in SerenityOS. Commit
6a728e2d76 introduced the MMIO method for
all devices, breaking Bochs and VirtualBox compatibility. Later in
commit 6a9dc5562d the classic IO method
was restored for VirtualBox graphics adapters.
QEMU and Bochs use the same PCI VID/DID (0x1234/0x1111) for the emulated
VGA adapter. To distinguish betwen QEMU and Bochs we use the PCI
revision ID field (0=Bochs, 2=QEMU).
This driver is not tested and probably not used on any modern hardware
machine, because it is plugged into the ISA bus and not the PCI bus.
Also, the run script doesn't utilize this device anymore, making it more
hard to test this driver and to ensure it doesn't rot.
The AP boot code was partially adapted to build on x86_64 but didn't
properly jump into 64 bit mode. Furthermore, the APIC code was still
using 32 bit pointers.
Fixes#12662
We already init receive buffer if we have singleport console, but if
we have multiport console that dynamically allocates ports we never
initted their receive buffers.
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.
While investigating why gdb is failing when it calls `PT_CONTINUE`
against Serenity I noticed that the names of the programs in the
System Monitor didn't make sense. They were seemingly stale.
After inspecting the kernel code, it became apparent that the sequence
occurs as follows:
1. Debugger calls `fork()`
2. The forked child calls `PT_TRACE_ME`
3. The `PT_TRACE_ME` instructs the forked process to block in the
kernel waiting for a signal from the tracer on the next call
to `execve(..)`.
4. Debugger waits for forked child to spawn and stop, and then it
calls `PT_ATTACH` followed by `PT_CONTINUE` on the child.
5. Currently the `PT_CONTINUE` fails because of some other yet to
be found bug.
6. The process name is set immediately AFTER we are woken up by
the `PT_CONTINUE` which never happens in the case I'm debugging.
This chain of events leaves the process suspended, with the name of
the original (forked) process instead of the name we inherit from
the `execve(..)` call.
To avoid such confusion in the future, we set the new name before we
block waiting for the tracer.
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.
Arguments larger than 32bit need to be passed as a pointer on a 32bit
architectures. sys$profiling_enable has u64 event_mask argument,
which means that it needs to be passed as an pointer. Previously upper
32bits were filled by garbage.
This prevents a kernel panic found in CI when m_receive_queue's size is
queried and found to be non-zero, then a different thread clears the
queue, and finally the first thread continues into the if block and
calls the queue's first() method, which then fails an assertion that
the queue's size is non-zero.
The SB16 card driver doesn't swallow more than 4096 bytes of data at
once, so instead of asserting just return ENOSPC for now.
To test this, either play normal sound or just this (very!) loud noise:
dd if=/dev/random of=/dev/audio/0 bs=4096
We have 3 new components:
1. The AudioManagement singleton. This class like in other subsystems,
is responsible to find hardware audio controllers and keep a reference
to them.
2. AudioController class - this class is the parent class for hardware
controllers like the Sound Blaster 16 or Intel 82801AA (AC97). For now,
this class has simple interface for getting and controlling sample rate
of audio channels, as well a write interface for specific audio channel
but not reading from it. One AudioController object might have multiple
AudioChannel "child" objects to hold with reference counting.
3. AudioChannel class - this is based on the CharacterDevice class, and
represents hardware PCM audio channel. It facilitates an ioctl interface
which should be consistent across all supported hardware currently.
It has a weak reference to a parent AudioController, and when trying to
write to a channel, it redirects the data to the parent AudioController.
Each audio channel device should be added into a new directory under the
/dev filesystem called "audio".
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.
This matches the likes of the adopt_{own, ref}_if_nonnull family and
also frees up the name to allow us to eventually add OOM-fallible
versions of these functions.
