aurora/lib/dolphin/os/OSMemory.cpp

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include <Windows.h>
#endif

#include "fmt/base.h"

#include <cassert>

#include "internal.hpp"
#include <dolphin/os.h>
#include "dolphin/types.h"

#if !NDEBUG && (INTPTR_MAX > INT32_MAX)
#define GUARD_MEMORY 1
#endif

uintptr_t OSBaseAddress = 0;

void* MEM1Start;
void* MEM1End;

static void GuardGCMemory();
static void* AllocMEM1(u32 size);

void AuroraOSInitMemory() {
  GuardGCMemory();

  if (aurora::g_config.mem1Size > 0) {
    MEM1Start = AllocMEM1(aurora::g_config.mem1Size);
    MEM1End = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(MEM1Start) + aurora::g_config.mem1Size);
    OSBaseAddress = reinterpret_cast<uintptr_t>(MEM1Start);
  }
}

#if GUARD_MEMORY
static uintptr_t GetAllocationGranularity() {
#if _WIN32
  SYSTEM_INFO sysInfo;
  GetSystemInfo(&sysInfo);

  return sysInfo.dwAllocationGranularity;
#else
  // TODO: posix impl
  return 0;
#endif
}

static void TryGuardRegion(const uintptr_t start, const uintptr_t end, char const* const name) {
#if _WIN32
  assert(start != 0);
  const auto addr = VirtualAlloc(
      reinterpret_cast<LPVOID>(start),
      end - start,
      MEM_RESERVE,
      PAGE_NOACCESS);

  if (addr == nullptr) {
    Log.debug("Unable to guard memory region: {}", name);
  } else {
    assert(addr == reinterpret_cast<LPVOID>(start));
    Log.debug("Successfully guarded memory range: {:08X}-{:08X} ({})", start, end, name);
  }
#else
  // TODO: posix impl
#endif
}

static void GuardGCMemory() {
  // Reserve the normal GC/Wii memory map so accesses are 100% guaranteed to fail.
  // https://www.gc-forever.com/yagcd/chap5.html#sec5.11
  // https://wiibrew.org/wiki/Memory_map

  // We can't quite map at address 0 (for good reasons) but we *can* map at the next granularity over!
  TryGuardRegion(0x00000000 + GetAllocationGranularity(), 0x017fffff, "MEM1 Physical");
  TryGuardRegion(0x80000000, 0x817fffff, "MEM1 Logical (cached)");
  TryGuardRegion(0xC0000000, 0xC17fffff, "MEM1 Logical (uncached)");
  TryGuardRegion(0x10000000, 0x13FFFFFF, "MEM2 Physical");
  TryGuardRegion(0x90000000, 0x93FFFFFF, "MEM2 Logical (cached)");
  TryGuardRegion(0xD0000000, 0xD3FFFFFF, "MEM2 Logical (uncached)");
  TryGuardRegion(0x08000000, 0x08300000, "EFB Physical");
  TryGuardRegion(0xC8000000, 0xC8300000, "EFB Logical");
  TryGuardRegion(0x0D000000, 0x0D008000, "Hollywood HW registers Physical");
  TryGuardRegion(0xCD000000, 0xCD008000, "Hollywood HW registers Logical");
  TryGuardRegion(0x0C000000, 0x0C008020, "Broadway/GC HW registers Physical");
  TryGuardRegion(0xCC000000, 0xCC008020, "Broadway/GC HW registers Logical");
  TryGuardRegion(0xe0000000, 0xe0003fff, "GC L2 cache");
  TryGuardRegion(0xfff00000, 0xffffffff, "GC IPL");
}
#else
static void GuardGCMemory() { }
#endif

#if _WIN64 && !NDEBUG
static void* AllocMEM1(u32 size) {
  // Allocate an entire 32-bit's worth of memory and allocate the real MEM1 in that.
  // This way, if a 64-bit pointer gets truncated to 32-bit, it will still fall in our guard pages.

  void* bulkChunk = VirtualAlloc(
    nullptr,
    8ll * 1024 * 1024 * 1024,
    MEM_RESERVE,
    PAGE_NOACCESS);

  if (bulkChunk == nullptr) {
    DWORD err = GetLastError();
    fmt::memory_buffer msg;
    fmt::format_system_error(
      msg,
      static_cast<int>(err),
      "Failed to allocate bulk chunk for MEM1");
    Log.fatal("{}", fmt::to_string(msg));
  }

  uintptr_t memSpace = (reinterpret_cast<uintptr_t>(bulkChunk) | 0xFFFFFFFF) + 1;
  void* mem1Address = reinterpret_cast<void*>(memSpace + 0x80000000);

  Log.debug("Reserved memory map at {:016X}-{:016X}", memSpace, memSpace + 0xFFFFFFFF);
  Log.debug(
    "MEM1 at {:016X}-{:016X}",
    reinterpret_cast<uintptr_t>(mem1Address),
    reinterpret_cast<uintptr_t>(mem1Address) + size);

  void* result = VirtualAlloc(mem1Address, size, MEM_COMMIT, PAGE_READWRITE);
  if (result == nullptr) {
    DWORD err = GetLastError();
    fmt::memory_buffer msg;
    fmt::format_system_error(
      msg,
      static_cast<int>(err),
      "Failed to commit memory for MEM1");
    Log.fatal("{}", fmt::to_string(msg));
  }

  assert(result == mem1Address);
  return result;
}
#else
static void* AllocMEM1(u32 size) {
  return calloc(1, size);
}
#endif

u32 OSGetPhysicalMemSize() {
  const auto info = static_cast<OSBootInfo*>(OSPhysicalToCached(0));
  return info->memorySize;
}