This enables the APIC timer on all CPUs, which means Scheduler::timer_tick
is now called on all CPUs independently. We still don't do anything on
the APs as it instantly crashes due to a number of other problems.
There are plenty of places in the kernel that aren't
checking if they actually got their allocation.
This fixes some of them, but definitely not all.
Fixes#3390Fixes#3391
Also, let's make find_one_free_page() return nullptr
if it doesn't get a free index. This stops the kernel
crashing when out of memory and allows memory purging
to take place again.
Fixes#3487
MemoryManager cannot use the Singleton class because
MemoryManager::initialize is called before the global constructors
are run. That caused the Singleton to be re-initialized, causing
it to create another MemoryManager instance.
Fixes#3226
We need to halt the BSP briefly until all APs are ready for the
first context switch, but we can't hold the same spinlock by all
of them while doing so. So, while the APs are waiting on each other
they need to release the scheduler lock, and then once signaled
re-acquire it. Should solve some timing dependent hangs or crashes,
most easily observed using qemu with kvm disabled.
We can now properly initialize all processors without
crashing by sending SMP IPI messages to synchronize memory
between processors.
We now initialize the APs once we have the scheduler running.
This is so that we can process IPI messages from the other
cores.
Also rework interrupt handling a bit so that it's more of a
1:1 mapping. We need to allocate non-sharable interrupts for
IPIs.
This also fixes the occasional hang/crash because all
CPUs now synchronize memory with each other.
This was supposed to be the foundation for some kind of pre-kernel
environment, but nobody is working on it right now, so let's move
everything back into the kernel and remove all the confusion.
Now we don't send raw numbers, but we let the IRQController object to
figure out the correct IRQ number.
This helps in a situation when we have 2 or more IOAPICs, so if IOAPIC
1 is assigned for IRQs 0-23 and IOAPIC 2 is assigned for IRQs 24-47,
if an IRQHandler of IRQ 25 invokes disable() for example, it will call
his responsible IRQController (IOAPIC 2), and the IRQController will
subtract the IRQ number with his assigned offset, and the result is that
the second redirection entry in IOAPIC 2 will be masked.
Also, duplicate data in dbg() and klog() calls were removed.
In addition, leakage of virtual address to kernel log is prevented.
This is done by replacing kprintf() calls to dbg() calls with the
leaked data instead.
Also, other kprintf() calls were replaced with klog().
Also, the enable() function is now correct and will use the right
registers and values. In addition to that, write_register() and
read_registers() are not relying on identity mapping anymore.
