The details of the specific interrupt bits that must be turned on are
irrelevant to the sys$execve implementation. Abstract it away to the
Processor implementations using the InterruptsState enum.
This commit adds Processor::set_thread_specific_data, and this function
is used to factor out architecture specific implementation of setting
the thread specific data. This function is implemented for
aarch64 and x86_64, and the callsites are changed to use this function
instead.
The handling of page tables is very architecture specific, so belongs
in the Arch directory. Some parts were already architecture-specific,
however this commit moves the rest of the PageDirectory class into the
Arch directory.
While we're here the aarch64/PageDirectory.{h,cpp} files are updated to
be aarch64 specific, by renaming some members and removing x86_64
specific code.
This removes the x86 specific hlt instruction from the scheduler, and
allows us to run the scheduler code for aarch64 by implementing
Processor::wait_for_interrupt for aarch64.
