Quake II needs a lot of stack, it was overflowing my 256 KiB stack so
this patch doubles that, so Quake II can run!
Also every thread had 256 KiB kernel stack. This is unnecessarily large
and now dropped to 32 KiB.
SSE is now unconditionally enabled any where and most of math.h is now
actually implemented. using __builtin_<func> lead to many hangs where
the builtin function would just call itself.
I had not understood how MSIs work and I was unnecessarily routing them
through IOAPIC. This is not necessary and should not be done :D
Also MSIs were reserving interrupts that IOAPIC was capable of
generating. Now IOAPIC and MSIs use different set of interrupts so
IOAPIC can use more interrupts if needed.
This patch builds new executable image to another pml4 structure and
only after everything is validated will current context be replaced.
This allows exec to fail "late" where previously it would panic the
kernel or kill the process. This allows graceful handling of exec
failures in userspace!
HPET supports reading LAPIC counter without locks, so it can be done in
parallel. This makes booting much faster. Previously initializing every
timer took 100 ms, so 16 CPUs took total of 1.6 seconds. This allows
doing it all in 100 ms.
Also SYS_CREATE_DIR now uses correct relative path. It used to always
create files relative to root. And as no permission checks were tested,
file creation succeeded to root as long as path did not contain '/' :D
ELFs are now loaded as MemoryRegions so they don't need special handling
anywhere. This also allows file backed COW optimizations to work. This
was not the case before.
This patch removes now obsolete LoadableELF and unused ELF files from
LibElf.
MemoryRegion::initialize() required size to be page aligned, this is not
necessary.
MemoryBackedRegion::copy_data_to_region() required user-write
permissions for underlying data. This did not matter as memory backed
regions dont support COW memory, but it could lead to bugs later on.