This patch adds a basic ELF program loader to the UserspaceEmulator and
creates MMU regions for each PT_LOAD header. (Note that we don't yet
respect the R/W/X flags etc.)
We also turn the SoftCPU into an X86::InstructionStream and give it an
EIP register so we can actually execute code by fetching memory through
our MMU abstraction.
This Emulator sub-object will keep track of all active memory regions
and handle memory read/write operations from the CPU.
A memory region is currently represented by a virtual Region object
that can implement arbitrary behavior by overriding read/write ops.
This introduces a new X86 CPU emulator for running SerenityOS userspace
programs in a virtualized interpreter environment.
The main goal is to be able to instrument memory accesses and catch
interesting bugs that are very hard to find otherwise. But before we
can do fancy things like that, we have to build a competent emulator
able to actually run programs.
This initial version is able to run a very small program that makes
some tiny syscalls, but nothing more.
