Initial support for xex patching

src/xenia/patcher/patcher.cc

@@ -0,0 +1,66 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2022 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+#include <cstring>
+
+#include "xenia/base/logging.h"
+#include "xenia/patcher/patcher.h"
+
+namespace xe {
+namespace patcher {
+
+Patcher::Patcher(const std::filesystem::path patches_root) {
+  is_any_patch_applied_ = false;
+  patch_db_ = new PatchDB(patches_root);
+}
+
+void Patcher::ApplyPatchesForTitle(Memory* memory, const uint32_t title_id,
+                                   const std::optional<uint64_t> hash) {
+  const auto title_patches = patch_db_->GetTitlePatches(title_id, hash);
+
+  for (const PatchFileEntry& patchFile : title_patches) {
+    for (const PatchInfoEntry& patchEntry : patchFile.patch_info) {
+      if (!patchEntry.is_enabled) {
+        continue;
+      }
+      XELOGE("Patcher: Applying patch for: {}({:08X}) - {}",
+             patchFile.title_name, patchFile.title_id, patchEntry.patch_name);
+      ApplyPatch(memory, &patchEntry);
+    }
+  }
+}
+
+void Patcher::ApplyPatch(Memory* memory, const PatchInfoEntry* patch) {
+  for (const PatchDataEntry& patch_data_entry : patch->patch_data) {
+    uint32_t old_address_protect = 0;
+    uint8_t* address = memory->TranslateVirtual(patch_data_entry.address);
+    xe::BaseHeap* heap = memory->LookupHeap(patch_data_entry.address);
+    if (!heap) {
+      continue;
+    }
+
+    heap->QueryProtect(patch_data_entry.address, &old_address_protect);
+
+    heap->Protect(patch_data_entry.address,
+                  (uint32_t)patch_data_entry.data.alloc_size,
+                  kMemoryProtectRead | kMemoryProtectWrite);
+
+    std::memcpy(address, patch_data_entry.data.patch_data.data(),
+                patch_data_entry.data.alloc_size);
+
+    // Restore previous protection
+    heap->Protect(patch_data_entry.address,
+                  (uint32_t)patch_data_entry.data.alloc_size,
+                  old_address_protect);
+
+    is_any_patch_applied_ = true;
+  }
+}
+
+}  // namespace patcher
+}  // namespace xe