diff --git a/src/xenia/cpu/backend/x64/x64_emitter.cc b/src/xenia/cpu/backend/x64/x64_emitter.cc
index 3b2104ada..c8053b05c 100644
--- a/src/xenia/cpu/backend/x64/x64_emitter.cc
+++ b/src/xenia/cpu/backend/x64/x64_emitter.cc
@@ -417,9 +417,8 @@ uint64_t UndefinedCallExtern(void* raw_context, uint64_t symbol_info_ptr) {
 }
 void X64Emitter::CallExtern(const hir::Instr* instr,
                             const FunctionInfo* symbol_info) {
-  if (!symbol_info->extern_handler()) {
-    CallNative(UndefinedCallExtern, reinterpret_cast<uint64_t>(symbol_info));
-  } else if (symbol_info->behavior() == FunctionBehavior::kBuiltin) {
+  if (symbol_info->behavior() == FunctionBehavior::kBuiltin &&
+      symbol_info->builtin_handler()) {
     // rcx = context
     // rdx = target host function
     // r8  = arg0
@@ -433,7 +432,8 @@ void X64Emitter::CallExtern(const hir::Instr* instr,
     ReloadECX();
     ReloadEDX();
     // rax = host return
-  } else if (symbol_info->behavior() == FunctionBehavior::kExtern) {
+  } else if (symbol_info->behavior() == FunctionBehavior::kExtern &&
+             symbol_info->extern_handler()) {
     // rcx = context
     // rdx = target host function
     mov(rdx, reinterpret_cast<uint64_t>(symbol_info->extern_handler()));
@@ -444,6 +444,8 @@ void X64Emitter::CallExtern(const hir::Instr* instr,
     ReloadECX();
     ReloadEDX();
     // rax = host return
+  } else {
+    CallNative(UndefinedCallExtern, reinterpret_cast<uint64_t>(symbol_info));
   }
 }
 
diff --git a/src/xenia/cpu/export_resolver.cc b/src/xenia/cpu/export_resolver.cc
index db829ee7d..386f78753 100644
--- a/src/xenia/cpu/export_resolver.cc
+++ b/src/xenia/cpu/export_resolver.cc
@@ -19,22 +19,20 @@ ExportResolver::ExportResolver() {}
 
 ExportResolver::~ExportResolver() {}
 
-void ExportResolver::RegisterTable(const std::string& library_name,
-                                   Export* exports, const size_t count) {
-  tables_.emplace_back(library_name, exports, count);
+void ExportResolver::RegisterTable(
+    const std::string& library_name,
+    const std::vector<xe::cpu::Export*>* exports) {
+  tables_.emplace_back(library_name, exports);
 }
 
 Export* ExportResolver::GetExportByOrdinal(const std::string& library_name,
                                            uint16_t ordinal) {
   for (const auto& table : tables_) {
     if (table.name == library_name || table.simple_name == library_name) {
-      // TODO(benvanik): binary search?
-      for (size_t n = 0; n < table.count; n++) {
-        if (table.exports[n].ordinal == ordinal) {
-          return &table.exports[n];
-        }
+      if (ordinal > table.exports->size()) {
+        return nullptr;
       }
-      return nullptr;
+      return table.exports->at(ordinal);
     }
   }
   return nullptr;
diff --git a/src/xenia/cpu/export_resolver.h b/src/xenia/cpu/export_resolver.h
index 19dd4dccd..153230036 100644
--- a/src/xenia/cpu/export_resolver.h
+++ b/src/xenia/cpu/export_resolver.h
@@ -89,8 +89,8 @@ class ExportResolver {
   ExportResolver();
   ~ExportResolver();
 
-  void RegisterTable(const std::string& library_name, Export* exports,
-                     const size_t count);
+  void RegisterTable(const std::string& library_name,
+                     const std::vector<Export*>* exports);
 
   Export* GetExportByOrdinal(const std::string& library_name, uint16_t ordinal);
 
@@ -105,10 +105,9 @@ class ExportResolver {
   struct ExportTable {
     std::string name;
     std::string simple_name;  // without extension
-    Export* exports;
-    size_t count;
-    ExportTable(const std::string& name, Export* exports, size_t count)
-        : name(name), exports(exports), count(count) {
+    const std::vector<Export*>* exports;
+    ExportTable(const std::string& name, const std::vector<Export*>* exports)
+        : name(name), exports(exports) {
       auto dot_pos = name.find_last_of('.');
       if (dot_pos != std::string::npos) {
         simple_name = name.substr(0, dot_pos);
diff --git a/src/xenia/cpu/xex_module.cc b/src/xenia/cpu/xex_module.cc
index 7c01f6810..66406d013 100644
--- a/src/xenia/cpu/xex_module.cc
+++ b/src/xenia/cpu/xex_module.cc
@@ -234,8 +234,13 @@ bool XexModule::SetupLibraryImports(const xe_xex2_import_library_t* library) {
 
         FunctionInfo::ExternHandler handler = 0;
         if (kernel_export) {
-          handler =
-              (FunctionInfo::ExternHandler)kernel_export->function_data.shim;
+          if (kernel_export->function_data.trampoline) {
+            handler = (FunctionInfo::ExternHandler)
+                          kernel_export->function_data.trampoline;
+          } else {
+            handler =
+                (FunctionInfo::ExternHandler)kernel_export->function_data.shim;
+          }
         } else {
           handler = UndefinedImport;
         }
diff --git a/src/xenia/kernel/xam_module.cc b/src/xenia/kernel/xam_module.cc
index 8f7530999..4ec00c02a 100644
--- a/src/xenia/kernel/xam_module.cc
+++ b/src/xenia/kernel/xam_module.cc
@@ -33,21 +33,35 @@ XamModule::XamModule(Emulator* emulator, KernelState* kernel_state)
   xam::RegisterVoiceExports(export_resolver_, kernel_state_);
 }
 
+std::vector<xe::cpu::Export*> xam_exports;
+
+xe::cpu::Export* RegisterExport_xam(xe::cpu::Export* export) {
+  if (xam_exports.size() <= export->ordinal) {
+    xam_exports.resize(xe::round_up(export->ordinal, 256));
+  }
+  xam_exports[export->ordinal] = export;
+  return export;
+}
+
 void XamModule::RegisterExportTable(xe::cpu::ExportResolver* export_resolver) {
   assert_not_null(export_resolver);
 
-  if (!export_resolver) {
-    return;
-  }
-
 // Build the export table used for resolution.
 #include "xenia/kernel/util/export_table_pre.inc"
   static xe::cpu::Export xam_export_table[] = {
 #include "xenia/kernel/xam_table.inc"
   };
 #include "xenia/kernel/util/export_table_post.inc"
-  export_resolver->RegisterTable("xam.xex", xam_export_table,
-                                 xe::countof(xam_export_table));
+  for (size_t i = 0; i < xe::countof(xam_export_table); ++i) {
+    auto& export = xam_export_table[i];
+    if (xam_exports.size() <= export.ordinal) {
+      xam_exports.resize(xe::round_up(export.ordinal, 256));
+    }
+    if (!xam_exports[export.ordinal]) {
+      xam_exports[export.ordinal] = &export;
+    }
+  }
+  export_resolver->RegisterTable("xam.xex", &xam_exports);
 }
 
 XamModule::~XamModule() {}
diff --git a/src/xenia/kernel/xam_module.h b/src/xenia/kernel/xam_module.h
index bb7f9b290..370ee472f 100644
--- a/src/xenia/kernel/xam_module.h
+++ b/src/xenia/kernel/xam_module.h
@@ -23,7 +23,6 @@ class XamModule : public XKernelModule {
   virtual ~XamModule();
 
   static void RegisterExportTable(xe::cpu::ExportResolver* export_resolver);
-  static void RegisterExport(xe::cpu::Export* export);
 
  private:
 };
diff --git a/src/xenia/kernel/xam_private.h b/src/xenia/kernel/xam_private.h
index 2bbfc527e..1167f68e0 100644
--- a/src/xenia/kernel/xam_private.h
+++ b/src/xenia/kernel/xam_private.h
@@ -18,6 +18,8 @@ namespace kernel {
 
 class KernelState;
 
+xe::cpu::Export* RegisterExport_xam(xe::cpu::Export* export);
+
 namespace xam {
 // Registration functions, one per file.
 void RegisterContentExports(xe::cpu::ExportResolver* export_resolver,
diff --git a/src/xenia/kernel/xboxkrnl_module.cc b/src/xenia/kernel/xboxkrnl_module.cc
index 583e572dd..c14cbcdfc 100644
--- a/src/xenia/kernel/xboxkrnl_module.cc
+++ b/src/xenia/kernel/xboxkrnl_module.cc
@@ -149,22 +149,36 @@ XboxkrnlModule::XboxkrnlModule(Emulator* emulator, KernelState* kernel_state)
       WT_EXECUTEINTIMERTHREAD);
 }
 
+std::vector<xe::cpu::Export*> xboxkrnl_exports;
+
+xe::cpu::Export* RegisterExport_xboxkrnl(xe::cpu::Export* export) {
+  if (xboxkrnl_exports.size() <= export->ordinal) {
+    xboxkrnl_exports.resize(xe::round_up(export->ordinal, 256));
+  }
+  xboxkrnl_exports[export->ordinal] = export;
+  return export;
+}
+
 void XboxkrnlModule::RegisterExportTable(
     xe::cpu::ExportResolver* export_resolver) {
   assert_not_null(export_resolver);
 
-  if (!export_resolver) {
-    return;
-  }
-
 // Build the export table used for resolution.
 #include "xenia/kernel/util/export_table_pre.inc"
   static xe::cpu::Export xboxkrnl_export_table[] = {
 #include "xenia/kernel/xboxkrnl_table.inc"
   };
 #include "xenia/kernel/util/export_table_post.inc"
-  export_resolver->RegisterTable("xboxkrnl.exe", xboxkrnl_export_table,
-                                 xe::countof(xboxkrnl_export_table));
+  for (size_t i = 0; i < xe::countof(xboxkrnl_export_table); ++i) {
+    auto& export = xboxkrnl_export_table[i];
+    if (xboxkrnl_exports.size() <= export.ordinal) {
+      xboxkrnl_exports.resize(xe::round_up(export.ordinal, 256));
+    }
+    if (!xboxkrnl_exports[export.ordinal]) {
+      xboxkrnl_exports[export.ordinal] = &export;
+    }
+  }
+  export_resolver->RegisterTable("xboxkrnl.exe", &xboxkrnl_exports);
 }
 
 XboxkrnlModule::~XboxkrnlModule() {
diff --git a/src/xenia/kernel/xboxkrnl_module.h b/src/xenia/kernel/xboxkrnl_module.h
index 61870ec02..5e34e6c70 100644
--- a/src/xenia/kernel/xboxkrnl_module.h
+++ b/src/xenia/kernel/xboxkrnl_module.h
@@ -28,7 +28,6 @@ class XboxkrnlModule : public XKernelModule {
   virtual ~XboxkrnlModule();
 
   static void RegisterExportTable(xe::cpu::ExportResolver* export_resolver);
-  static void RegisterExport(xe::cpu::Export* export);
 
   int LaunchModule(const char* path);
 
diff --git a/src/xenia/kernel/xboxkrnl_private.h b/src/xenia/kernel/xboxkrnl_private.h
index 042279cba..be0ff9267 100644
--- a/src/xenia/kernel/xboxkrnl_private.h
+++ b/src/xenia/kernel/xboxkrnl_private.h
@@ -17,6 +17,8 @@ namespace kernel {
 
 class KernelState;
 
+xe::cpu::Export* RegisterExport_xboxkrnl(xe::cpu::Export* export);
+
 namespace xboxkrnl {
 // Registration functions, one per file.
 void RegisterAudioExports(xe::cpu::ExportResolver* export_resolver,