Add support for a version 2 of "main bin spec" Mach-O LC_NOTE in corefiles, handle specifications with a slide value

[jasonmolenda]

Summary

The Mach-O corefiles have a "main bin spec" LC_NOTE which allows the corefile creator to specify a binary's UUID, load address, and type (userland, kernel, frimware). This patch extends that structure with two new fields - an optional slide, and an optional platform (currently unused).

We have a corefile creator that will only know the offset that a binary was loaded at, as well as its UUID, so lldb will need to find the original binary and add the offset to its file address to get the correct load address.

I changed the ObjectFile::GetCorefileMainBinaryInfo method from taking a load address, to taking a value and a bool of whether the value is an address or an offset. This is based on Module::SetLoadAddress, and it seemed good to stick with that argument style.

The majority of the patch is changing TestFirmwareCorefiles.py. I changed create-empty-corefile.cpp to work on Intel or Apple Silicon macs, have it generate version 2 of the 'main bin spec' LC_NOTE, both with an address and with a slide.

[JDevlieghere]

A few small nits but the change itself looks sound to me. LGTM.

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

7052

No need to change this, but if you ever have situation where the buffer is variable length, LLVM's formatv makes this very easy:

std::string s = llvm::formatv("mem-image+{0:x}", image.load_address)

lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp

223

You can hoist this out of the if-check and reuse it in all the blocks instead of having to duplicate the variable each time.

229

When I was reading this code, I found this a little confusing, given that value_is_offset is an input parameter and this is meant as a constant. Not sure how to make this better other than possibly using /*value_is_offset=*/ true. Anyway small nit, don't feel like you need to change anything here.

lldb/test/API/macosx/lc-note/firmware-corefile/TestFirmwareCorefiles.py

242–243

Nice

250–251

Given that you already build the corefiles only once, would it make sense to make these separate tests so that *if* they fail, you can immediately tell from the logs? Or maybe these tests are sharing something that I missed?

264

I believe you need to pass exist_ok to avoid this failing when the dir already exists.

271

os.path.join

278

We shouldn't be hardcoding this, we already have llvm-dwarfdump as a test dependency. That said, unlike dsymutil there's no good way to get the dwarfdump binary. There's other tests doing the same, so we (I?) should address this in another patch.

287–314

I feel like we have a handful of tests creating this dsymforuuid wrapper. At some point we should consider moving this in the lldbutil so we don't have to copy-paste this everywhere.

[jasonmolenda]

Update patch to address Jonas' feedback. Most of the changes in this update are to TestFirmwareCorefiles.py, cleaning its structure up given how the test has grown over time.

lldb/include/lldb/Symbol/ObjectFile.h

public:
   virtual lldb::addr_t GetAddressMask() { return 0; }
 
   /// When the ObjectFile is a core file, lldb needs to locate the "binary" in
   /// the core file.  lldb can iterate over the pages looking for a valid
   /// binary, but some core files may have metadata  describing where the main
   /// binary is exactly which removes ambiguity when there are multiple
   /// binaries present in the captured memory pages.
   ///
-  /// \param[out] address
-  ///   If the address of the binary is specified, this will be set.
-  ///   This is an address is the virtual address space of the core file
-  ///   memory segments; it is not an offset into the object file.
-  ///   If no address is available, will be set to LLDB_INVALID_ADDRESS.
+  /// \param[out] value
+  ///   The address or offset (slide) where the binary is loaded in memory.
+  ///   LLDB_INVALID_ADDRESS for unspecified.  If an offset is given,
+  ///   this offset should be added to the binary's file address to get
+  ///   the load address.
+  ///
+  /// \param[out] value_is_offset
+  ///   Specifies if \b value is a load address, or an offset to calculate
+  ///   the load address.
   ///
   /// \param[out] uuid
   ///   If the uuid of the binary is specified, this will be set.
   ///   If no UUID is available, will be cleared.
   ///
   /// \param[out] type
   ///   Return the type of the binary, which will dictate which
   ///   DynamicLoader plugin should be used.
   ///
   /// \return
   ///   Returns true if either address or uuid has been set.
-  virtual bool GetCorefileMainBinaryInfo(lldb::addr_t &address, UUID &uuid,
+  virtual bool GetCorefileMainBinaryInfo(lldb::addr_t &value,
+                                         bool &value_is_offset, UUID &uuid,
                                          ObjectFile::BinaryType &type) {
-    address = LLDB_INVALID_ADDRESS;
+    value = LLDB_INVALID_ADDRESS;
+    value_is_offset = false;
     uuid.Clear();
     return false;
   }
 
   virtual lldb::RegisterContextSP
   GetThreadContextAtIndex(uint32_t idx, lldb_private::Thread &thread) {
     return lldb::RegisterContextSP();
   }

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h

public:
   lldb_private::Address GetBaseAddress() override;
 
   uint32_t GetNumThreadContexts() override;
 
   std::string GetIdentifierString() override;
 
   lldb::addr_t GetAddressMask() override;
 
-  bool GetCorefileMainBinaryInfo(lldb::addr_t &address,
+  bool GetCorefileMainBinaryInfo(lldb::addr_t &value, bool &value_is_offset,
                                  lldb_private::UUID &uuid,
                                  ObjectFile::BinaryType &type) override;
 
   bool LoadCoreFileImages(lldb_private::Process &process) override;
 
   lldb::RegisterContextSP
   GetThreadContextAtIndex(uint32_t idx, lldb_private::Thread &thread) override;
 

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

for (uint32_t i = 0; i < m_header.ncmds; ++i) {
         }
       }
       offset = cmd_offset + lc.cmdsize;
     }
   }
   return mask;
 }
 
-bool ObjectFileMachO::GetCorefileMainBinaryInfo(addr_t &address, UUID &uuid,
+bool ObjectFileMachO::GetCorefileMainBinaryInfo(addr_t &value,
+                                                bool &value_is_offset,
+                                                UUID &uuid,
                                                 ObjectFile::BinaryType &type) {
-  address = LLDB_INVALID_ADDRESS;
+  value = LLDB_INVALID_ADDRESS;
+  value_is_offset = false;
   uuid.Clear();
+  uint32_t log2_pagesize = 0; // not currently passed up to caller
+  uint32_t platform = 0;      // not currently passed up to caller
   ModuleSP module_sp(GetModule());
   if (module_sp) {
     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
     lldb::offset_t offset = MachHeaderSizeFromMagic(m_header.magic);
     for (uint32_t i = 0; i < m_header.ncmds; ++i) {
       const uint32_t cmd_offset = offset;
       llvm::MachO::load_command lc;
       if (m_data.GetU32(&offset, &lc.cmd, 2) == nullptr)
         break;
       if (lc.cmd == LC_NOTE) {
         char data_owner[17];
         memset(data_owner, 0, sizeof(data_owner));
         m_data.CopyData(offset, 16, data_owner);
         offset += 16;
         uint64_t fileoff = m_data.GetU64_unchecked(&offset);
         uint64_t size = m_data.GetU64_unchecked(&offset);
 
+        // struct main_bin_spec
+        // {
+        //     uint32_t version;       // currently 2
+        //     uint32_t type;          // 0 == unspecified, 1 == kernel,
+        //                             // 2 == user process,
+        //                             // 3 == standalone binary
+        //     uint64_t address;       // UINT64_MAX if address not specified
+        //     uint64_t slide;         // slide, UINT64_MAX if unspecified
+        //                             // 0 if no slide needs to be applied to
+        //                             // file address
+        //     uuid_t   uuid;          // all zero's if uuid not specified
+        //     uint32_t log2_pagesize; // process page size in log base 2,
+        //                             // e.g. 4k pages are 12.
+        //                             // 0 for unspecified
+        //     uint32_t platform;      // The Mach-O platform for this corefile.
+        //                             // 0 for unspecified.
+        //                             // The values are defined in
+        //                             // <mach-o/loader.h>, PLATFORM_*.
+        // } __attribute((packed));
+
         // "main bin spec" (main binary specification) data payload is
         // formatted:
         //    uint32_t version       [currently 1]
         //    uint32_t type          [0 == unspecified, 1 == kernel,
         //                            2 == user process, 3 == firmware ]
         //    uint64_t address       [ UINT64_MAX if address not specified ]
         //    uuid_t   uuid          [ all zero's if uuid not specified ]
         //    uint32_t log2_pagesize [ process page size in log base
         //                             2, e.g. 4k pages are 12.
         //                             0 for unspecified ]
         //    uint32_t unused        [ for alignment ]
 
         if (strcmp("main bin spec", data_owner) == 0 && size >= 32) {
           offset = fileoff;
           uint32_t version;
-          if (m_data.GetU32(&offset, &version, 1) != nullptr && version == 1) {
+          if (m_data.GetU32(&offset, &version, 1) != nullptr && version <= 2) {
             uint32_t binspec_type = 0;
             uuid_t raw_uuid;
             memset(raw_uuid, 0, sizeof(uuid_t));
 
-            if (m_data.GetU32(&offset, &binspec_type, 1) &&
-                m_data.GetU64(&offset, &address, 1) &&
-                m_data.CopyData(offset, sizeof(uuid_t), raw_uuid) != 0) {
+            if (!m_data.GetU32(&offset, &binspec_type, 1))
+              return false;
+            if (!m_data.GetU64(&offset, &value, 1))
+              return false;
+            uint64_t slide = LLDB_INVALID_ADDRESS;
+            if (version > 1 && !m_data.GetU64(&offset, &slide, 1))
+              return false;
+            if (value == LLDB_INVALID_ADDRESS &&
+                slide != LLDB_INVALID_ADDRESS) {
+              value = slide;
+              value_is_offset = true;
+            }
+
+            if (m_data.CopyData(offset, sizeof(uuid_t), raw_uuid) != 0) {
               uuid = UUID::fromOptionalData(raw_uuid, sizeof(uuid_t));
               // convert the "main bin spec" type into our
               // ObjectFile::BinaryType enum
               switch (binspec_type) {
               case 0:
                 type = eBinaryTypeUnknown;
                 break;
               case 1:
                 type = eBinaryTypeKernel;
                 break;
               case 2:
                 type = eBinaryTypeUser;
                 break;
               case 3:
                 type = eBinaryTypeStandalone;
                 break;
               }
+              if (!m_data.GetU32(&offset, &log2_pagesize, 1))
+                return false;
+              if (version > 1 && !m_data.GetU32(&offset, &platform, 1))
+                return false;
               return true;
             }
           }
         }
       }
       offset = cmd_offset + lc.cmdsize;
     }
   }

 bool ObjectFileMachO::LoadCoreFileImages(lldb_private::Process &process) {
   MachOCorefileAllImageInfos image_infos = GetCorefileAllImageInfos();
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
 
   ModuleList added_modules;
   for (const MachOCorefileImageEntry &image : image_infos.all_image_infos) {
     ModuleSpec module_spec;
     module_spec.GetUUID() = image.uuid;
+    if (image.filename.empty()) {
+      char namebuf[80];
+      if (image.load_address != LLDB_INVALID_ADDRESS)
+        snprintf(namebuf, sizeof(namebuf), "mem-image-0x%" PRIx64,
+                 image.load_address);
+      else
+        snprintf(namebuf, sizeof(namebuf), "mem-image+0x%" PRIx64, image.slide);
+      module_spec.GetFileSpec() = FileSpec(namebuf);
+    } else {
       module_spec.GetFileSpec() = FileSpec(image.filename.c_str());
+    }
     if (image.currently_executing) {
       Symbols::DownloadObjectAndSymbolFile(module_spec, true);
       if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
         process.GetTarget().GetOrCreateModule(module_spec, false);
       }
     }
     Status error;
     ModuleSP module_sp =

lldb/source/Plugins/Process/mach-core/ProcessMachCore.cpp

bool ProcessMachCore::GetDynamicLoaderAddress(lldb::addr_t addr) {
   }
   return false;
 }
 
 // We have a hint about a binary -- a UUID, possibly a load address.
 // Try to load a file with that UUID into lldb, and if we have a load
 // address, set it correctly.  Else assume that the binary was loaded
 // with no slide.
-static bool load_standalone_binary(UUID uuid, addr_t addr, Target &target) {
+static bool load_standalone_binary(UUID uuid, addr_t value,
+                                   bool value_is_offset, Target &target) {
   if (uuid.IsValid()) {
     ModuleSpec module_spec;
     module_spec.GetUUID() = uuid;
 
     // Look up UUID in global module cache before attempting
     // dsymForUUID-like action.
     ModuleSP module_sp;
     Status error = ModuleList::GetSharedModule(module_spec, module_sp, nullptr,
                                                nullptr, nullptr);
 
     if (!module_sp.get()) {
       // Force a a dsymForUUID lookup, if that tool is available.
       if (!module_spec.GetSymbolFileSpec())
         Symbols::DownloadObjectAndSymbolFile(module_spec, true);
 
       if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
         module_sp = std::make_shared<Module>(module_spec);
       }
     }
 
-    if (module_sp.get() && module_sp->GetObjectFile()) {
+    // If we couldn't find the binary anywhere else, as a last resort,
+    // read it out of memory in the corefile.
+    if (!module_sp.get() && value != LLDB_INVALID_ADDRESS && !value_is_offset) {
+      char namebuf[80];
+      snprintf(namebuf, sizeof(namebuf), "mem-image-0x%" PRIx64, value);
+      module_sp =
+          target.GetProcessSP()->ReadModuleFromMemory(FileSpec(namebuf), value);
+    }
+
+    if (module_sp.get()) {
       target.SetArchitecture(module_sp->GetObjectFile()->GetArchitecture());
       target.GetImages().AppendIfNeeded(module_sp, false);
 
-      Address base_addr = module_sp->GetObjectFile()->GetBaseAddress();
-      addr_t slide = 0;
-      if (addr != LLDB_INVALID_ADDRESS && base_addr.IsValid()) {
-        addr_t file_load_addr = base_addr.GetFileAddress();
-        slide = addr - file_load_addr;
-      }
       bool changed = false;
-      module_sp->SetLoadAddress(target, slide, true, changed);
+      if (module_sp->GetObjectFile()) {
+        if (value != LLDB_INVALID_ADDRESS) {
+          module_sp->SetLoadAddress(target, value, value_is_offset, changed);
+        } else {
+          // No address/offset/slide, load the binary at file address,
+          // offset 0.
+          const bool value_is_slide = true;
+          module_sp->SetLoadAddress(target, 0, value_is_slide, changed);
+        }
+      } else {
+        // In-memory image, load at its true address, offset 0.
+        const bool value_is_slide = true;
+        module_sp->SetLoadAddress(target, 0, value_is_slide, changed);
+      }
 
       ModuleList added_module;
       added_module.Append(module_sp, false);
       target.ModulesDidLoad(added_module);
 
       // Flush info in the process (stack frames, etc).
       ProcessSP process_sp(target.GetProcessSP());
       if (process_sp)
Status ProcessMachCore::DoLoadCore() {
   }
   if (!ranges_are_sorted) {
     m_core_aranges.Sort();
     m_core_range_infos.Sort();
   }
 
   bool found_main_binary_definitively = false;
 
-  addr_t objfile_binary_addr;
+  addr_t objfile_binary_value;
+  bool objfile_binary_value_is_offset;
   UUID objfile_binary_uuid;
   ObjectFile::BinaryType type;
-  if (core_objfile->GetCorefileMainBinaryInfo(objfile_binary_addr,
+  if (core_objfile->GetCorefileMainBinaryInfo(objfile_binary_value,
+                                              objfile_binary_value_is_offset,
                                               objfile_binary_uuid, type)) {
     if (log) {
       log->Printf(
           "ProcessMachCore::DoLoadCore: using binary hint from 'main bin spec' "
-          "LC_NOTE with UUID %s address 0x%" PRIx64 " and type %d",
-          objfile_binary_uuid.GetAsString().c_str(), objfile_binary_addr, type);
+          "LC_NOTE with UUID %s value 0x%" PRIx64
+          " value is offset %d and type %d",
+          objfile_binary_uuid.GetAsString().c_str(), objfile_binary_value,
+          objfile_binary_value_is_offset, type);
     }
-    if (objfile_binary_addr != LLDB_INVALID_ADDRESS) {
+    if (objfile_binary_value != LLDB_INVALID_ADDRESS &&
+        !objfile_binary_value_is_offset) {
       if (type == ObjectFile::eBinaryTypeUser) {
-        m_dyld_addr = objfile_binary_addr;
+        m_dyld_addr = objfile_binary_value;
         m_dyld_plugin_name = DynamicLoaderMacOSXDYLD::GetPluginNameStatic();
         found_main_binary_definitively = true;
       }
       if (type == ObjectFile::eBinaryTypeKernel) {
-        m_mach_kernel_addr = objfile_binary_addr;
+        m_mach_kernel_addr = objfile_binary_value;
         m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
         found_main_binary_definitively = true;
       }
     }
     if (!found_main_binary_definitively) {
       // ObjectFile::eBinaryTypeStandalone, undeclared types
-      if (load_standalone_binary(objfile_binary_uuid, objfile_binary_addr,
-                                 GetTarget())) {
+      if (load_standalone_binary(objfile_binary_uuid, objfile_binary_value,
+                                 objfile_binary_value_is_offset, GetTarget())) {
         found_main_binary_definitively = true;
         m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
       }
     }
   }
 
   // This checks for the presence of an LC_IDENT string in a core file;
   // LC_IDENT is very obsolete and should not be used in new code, but if the
if (!found_main_binary_definitively) {
     if (corefile_identifier.find("Darwin Kernel") != std::string::npos &&
         ident_uuid.IsValid() && ident_binary_addr != LLDB_INVALID_ADDRESS) {
       if (log)
         log->Printf("ProcessMachCore::DoLoadCore: Found kernel binary via "
                     "LC_IDENT/kern ver str LC_NOTE");
       m_mach_kernel_addr = ident_binary_addr;
       found_main_binary_definitively = true;
     } else if (ident_uuid.IsValid()) {
-      if (load_standalone_binary(ident_uuid, ident_binary_addr, GetTarget())) {
+      // We have no address specified, only a UUID.  Load it at the file
+      // address.
+      const bool value_is_offset = false;
+      if (load_standalone_binary(ident_uuid, ident_binary_addr, value_is_offset,
+                                 GetTarget())) {
         found_main_binary_definitively = true;
         m_dyld_plugin_name = DynamicLoaderStatic::GetPluginNameStatic();
       }
     }
   }
 
+  bool did_load_extra_binaries = core_objfile->LoadCoreFileImages(*this);
   // If we have a "all image infos" LC_NOTE, try to load all of the
   // binaries listed, and set their Section load addresses in the Target.
-  if (found_main_binary_definitively == false &&
-      core_objfile->LoadCoreFileImages(*this)) {
+  if (found_main_binary_definitively == false && did_load_extra_binaries) {
     m_dyld_plugin_name = DynamicLoaderDarwinKernel::GetPluginNameStatic();
     found_main_binary_definitively = true;
   }
 
   if (!found_main_binary_definitively &&
       (m_dyld_addr == LLDB_INVALID_ADDRESS ||
        m_mach_kernel_addr == LLDB_INVALID_ADDRESS)) {
     // We need to locate the main executable in the memory ranges we have in

lldb/test/API/macosx/lc-note/firmware-corefile/TestFirmwareCorefiles.py

 from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
 
 
 class TestFirmwareCorefiles(TestBase):
 
     mydir = TestBase.compute_mydir(__file__)
 
-    def initial_setup(self):
+    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
+    @skipIf(archs=no_match(['x86_64', 'arm64', 'arm64e', 'aarch64']))
+    @skipIfRemote
+    @skipUnlessDarwin
+    def test_lc_note_version_string(self):
+        self.build()
+        aout_exe_basename = "a.out"
+        aout_exe = self.getBuildArtifact(aout_exe_basename)
+        verstr_corefile = self.getBuildArtifact("verstr.core")
+        verstr_corefile_addr = self.getBuildArtifact("verstr-addr.core")
+        create_corefile = self.getBuildArtifact("create-empty-corefile")
+        slide = 0x70000000000
+        call(create_corefile + " version-string " + verstr_corefile + " " + aout_exe + " 0xffffffffffffffff 0xffffffffffffffff", shell=True)
+        call(create_corefile + " version-string " + verstr_corefile_addr + " " + aout_exe + (" 0x%x" % slide) + " 0xffffffffffffffff", shell=True)
+
+        if self.TraceOn():
+            self.runCmd("log enable lldb dyld host")
+            self.addTearDownHook(lambda: self.runCmd("log disable lldb dyld host"))
+
+        # Register the a.out binary with this UUID in lldb's global module
+        # cache, then throw the Target away.
+        target = self.dbg.CreateTarget(aout_exe)
+        self.dbg.DeleteTarget(target)
+
+        # First, try the "kern ver str" corefile
+        target = self.dbg.CreateTarget('')
+        err = lldb.SBError()
+        if self.TraceOn():
+            self.runCmd("script print('loading corefile %s')" % verstr_corefile)
+        process = target.LoadCore(verstr_corefile)
+        self.assertEqual(process.IsValid(), True)
+        if self.TraceOn():
+            self.runCmd("image list")
+            self.runCmd("target mod dump sections")
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
+        self.dbg.DeleteTarget(target)
+
+        # Second, try the "kern ver str" corefile where it loads at an address
+        target = self.dbg.CreateTarget('')
+        err = lldb.SBError()
+        if self.TraceOn():
+            self.runCmd("script print('loading corefile %s')" % verstr_corefile_addr)
+        process = target.LoadCore(verstr_corefile_addr)
+        self.assertEqual(process.IsValid(), True)
+        if self.TraceOn():
+            self.runCmd("image list")
+            self.runCmd("target mod dump sections")
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
+        main_sym = target.GetModuleAtIndex(0).FindSymbol("main", lldb.eSymbolTypeAny)
+        main_addr = main_sym.GetStartAddress()
+        self.assertGreater(main_addr.GetLoadAddress(target), slide)
+        self.assertNotEqual(main_addr.GetLoadAddress(target), lldb.LLDB_INVALID_ADDRESS)
+        self.dbg.DeleteTarget(target)
+
+    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
+    @skipIf(archs=no_match(['x86_64', 'arm64', 'arm64e', 'aarch64']))
+    @skipIfRemote
+    @skipUnlessDarwin
+    def test_lc_note_main_bin_spec(self):
         self.build()
-        self.aout_exe = self.getBuildArtifact("a.out")
-        self.aout_exe_basename = "a.out"
-        self.create_corefile = self.getBuildArtifact("create-empty-corefile")
-        self.dsym_for_uuid = self.getBuildArtifact("dsym-for-uuid.sh")
-        self.verstr_corefile = self.getBuildArtifact("verstr.core")
-        self.verstr_corefile_addr = self.getBuildArtifact("verstr-addr.core")
-        self.binspec_corefile = self.getBuildArtifact("binspec.core")
-        self.binspec_corefile_addr = self.getBuildArtifact("binspec-addr.core")
+        aout_exe_basename = "a.out"
+        aout_exe = self.getBuildArtifact(aout_exe_basename)
+        create_corefile = self.getBuildArtifact("create-empty-corefile")
+        binspec_corefile = self.getBuildArtifact("binspec.core")
+        binspec_corefile_addr = self.getBuildArtifact("binspec-addr.core")
+        binspec_corefile_slideonly = self.getBuildArtifact("binspec-addr-slideonly.core")
+
+        slide = 0x70000000000
+
+        ### Create our corefile
+        # 0xffffffffffffffff means load address unknown
+        call(create_corefile + " main-bin-spec " + binspec_corefile + " " + aout_exe + " 0xffffffffffffffff 0xffffffffffffffff", shell=True)
+        call(create_corefile + " main-bin-spec " + binspec_corefile_addr + " " + aout_exe + (" 0x%x" % slide) + " 0xffffffffffffffff", shell=True)
+        call(create_corefile + " main-bin-spec " + binspec_corefile_slideonly + " " + aout_exe + " 0xffffffffffffffff" + (" 0x%x" % slide), shell=True)
+
+        if self.TraceOn():
+            self.runCmd("log enable lldb dyld host")
+            self.addTearDownHook(lambda: self.runCmd("log disable lldb dyld host"))
+
+        # Register the a.out binary with this UUID in lldb's global module
+        # cache, then throw the Target away.
+        target = self.dbg.CreateTarget(aout_exe)
+        self.dbg.DeleteTarget(target)
+
+        # First, try the "main bin spec" corefile
+        target = self.dbg.CreateTarget('')
+        if self.TraceOn():
+            self.runCmd("script print('loading corefile %s')" % binspec_corefile)
+        process = target.LoadCore(binspec_corefile)
+        self.assertEqual(process.IsValid(), True)
+        if self.TraceOn():
+            self.runCmd("image list")
+            self.runCmd("target mod dump sections")
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
+        self.dbg.DeleteTarget(target)
+
+        # Second, try the "main bin spec" corefile where it loads at an address
+        target = self.dbg.CreateTarget('')
+        if self.TraceOn():
+            self.runCmd("script print('loading corefile %s')" % binspec_corefile_addr)
+        process = target.LoadCore(binspec_corefile_addr)
+        self.assertEqual(process.IsValid(), True)
+        if self.TraceOn():
+            self.runCmd("image list")
+            self.runCmd("target mod dump sections")
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
+        main_sym = target.GetModuleAtIndex(0).FindSymbol("main", lldb.eSymbolTypeAny)
+        main_addr = main_sym.GetStartAddress()
+        self.assertGreater(main_addr.GetLoadAddress(target), slide)
+        self.assertNotEqual(main_addr.GetLoadAddress(target), lldb.LLDB_INVALID_ADDRESS)
+        self.dbg.DeleteTarget(target)
+
+        # Third, try the "main bin spec" corefile where it loads at a slide
+        target = self.dbg.CreateTarget('')
+        if self.TraceOn():
+            self.runCmd("script print('loading corefile %s')" % binspec_corefile_slideonly)
+        process = target.LoadCore(binspec_corefile_slideonly)
+        self.assertEqual(process.IsValid(), True)
+        if self.TraceOn():
+            self.runCmd("image list")
+            self.runCmd("target mod dump sections")
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
+        main_sym = target.GetModuleAtIndex(0).FindSymbol("main", lldb.eSymbolTypeAny)
+        main_addr = main_sym.GetStartAddress()
+        self.assertGreater(main_addr.GetLoadAddress(target), slide)
+        self.assertNotEqual(main_addr.GetLoadAddress(target), lldb.LLDB_INVALID_ADDRESS)
+        self.dbg.DeleteTarget(target)
+
+    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
+    @skipIf(archs=no_match(['x86_64', 'arm64', 'arm64e', 'aarch64']))
+    @skipIfRemote
+    @skipUnlessDarwin
+    def test_lc_note_main_bin_spec_os_plugin(self):
+
+        self.build()
+        aout_exe = self.getBuildArtifact("a.out")
+        aout_exe_basename = "a.out"
+        create_corefile = self.getBuildArtifact("create-empty-corefile")
+        binspec_corefile_addr = self.getBuildArtifact("binspec-addr.core")
+
+        slide = 0x70000000000
+
+        ### Create our corefile
+        # 0xffffffffffffffff means load address unknown
+        call(create_corefile + " main-bin-spec " + binspec_corefile_addr + " " + aout_exe + (" 0x%x" % slide) + " 0xffffffffffffffff", shell=True)
 
         ## We can hook in our dsym-for-uuid shell script to lldb with this env
         ## var instead of requiring a defaults write.
-        os.environ['LLDB_APPLE_DSYMFORUUID_EXECUTABLE'] = self.dsym_for_uuid
+        dsym_for_uuid = self.getBuildArtifact("dsym-for-uuid.sh")
+        os.environ['LLDB_APPLE_DSYMFORUUID_EXECUTABLE'] = dsym_for_uuid
+        if self.TraceOn():
+            print("Setting env var LLDB_APPLE_DSYMFORUUID_EXECUTABLE=" + dsym_for_uuid)
         self.addTearDownHook(lambda: os.environ.pop('LLDB_APPLE_DSYMFORUUID_EXECUTABLE', None))
 
         self.runCmd("settings set target.load-script-from-symbol-file true")
         self.addTearDownHook(lambda: self.runCmd("settings set target.load-script-from-symbol-file false"))
 
-        dsym_python_dir = '%s.dSYM/Contents/Resources/Python' % (self.aout_exe)
+        dsym_python_dir = os.path.join('%s.dSYM' % aout_exe, 'Contents', 'Resources', 'Python')
         os.makedirs(dsym_python_dir)
         python_os_plugin_path = os.path.join(self.getSourceDir(),
                                              'operating_system.py')
         python_init = [
                 'def __lldb_init_module(debugger, internal_dict):',
                 '  debugger.HandleCommand(\'settings set target.process.python-os-plugin-path %s\')' % python_os_plugin_path,
                 ]
-        with open(dsym_python_dir + "/a_out.py", "w") as writer:
+        with open(os.path.join(dsym_python_dir, "a_out.py"), "w") as writer:
             for l in python_init:
                 writer.write(l + '\n')
 
         dwarfdump_uuid_regex = re.compile(
             'UUID: ([-0-9a-fA-F]+) \(([^\(]+)\) .*')
         dwarfdump_cmd_output = subprocess.check_output(
-                ('/usr/bin/dwarfdump --uuid "%s"' % self.aout_exe), shell=True).decode("utf-8")
+                ('/usr/bin/dwarfdump --uuid "%s"' % aout_exe), shell=True).decode("utf-8")
         aout_uuid = None
         for line in dwarfdump_cmd_output.splitlines():
             match = dwarfdump_uuid_regex.search(line)
             if match:
                 aout_uuid = match.group(1)
         self.assertNotEqual(aout_uuid, None, "Could not get uuid of built a.out")
 
-        ###  Create our dsym-for-uuid shell script which returns self.aout_exe
+        ###  Create our dsym-for-uuid shell script which returns aout_exe
         shell_cmds = [
                 '#! /bin/sh',
                 '# the last argument is the uuid',
                 'while [ $# -gt 1 ]',
                 'do',
                 '  shift',
                 'done',
                 'ret=0',
                 'echo "<?xml version=\\"1.0\\" encoding=\\"UTF-8\\"?>"',
                 'echo "<!DOCTYPE plist PUBLIC \\"-//Apple//DTD PLIST 1.0//EN\\" \\"http://www.apple.com/DTDs/PropertyList-1.0.dtd\\">"',
                 'echo "<plist version=\\"1.0\\">"',
                 '',
                 'if [ "$1" != "%s" ]' % (aout_uuid),
                 'then',
                 '  echo "<key>DBGError</key><string>not found</string>"',
                 '  echo "</plist>"', 
                 '  exit 1',
                 'fi',
                 '  uuid=%s' % aout_uuid,
-                '  bin=%s' % self.aout_exe,
-                '  dsym=%s.dSYM/Contents/Resources/DWARF/%s' % (self.aout_exe, os.path.basename(self.aout_exe)),
+                '  bin=%s' % aout_exe,
+                '  dsym=%s.dSYM/Contents/Resources/DWARF/%s' % (aout_exe, os.path.basename(aout_exe)),
                 'echo "<dict><key>$uuid</key><dict>"',
                 '',
                 'echo "<key>DBGDSYMPath</key><string>$dsym</string>"',
                 'echo "<key>DBGSymbolRichExecutable</key><string>$bin</string>"',
                 'echo "</dict></dict></plist>"',
                 'exit $ret'
                 ]
 
-        with open(self.dsym_for_uuid, "w") as writer:
+        with open(dsym_for_uuid, "w") as writer:
             for l in shell_cmds:
                 writer.write(l + '\n')
 
-        os.chmod(self.dsym_for_uuid, 0o755)
-
-        self.slide = 0x70000000000
-
-        ### Create our corefile
-        # 0xffffffffffffffff means load address unknown
-        retcode = call(self.create_corefile + " version-string " + self.verstr_corefile + " " + self.aout_exe + " 0xffffffffffffffff", shell=True)
-        retcode = call(self.create_corefile + " version-string " + self.verstr_corefile_addr + " " + self.aout_exe + (" 0x%x" % self.slide), shell=True)
-        retcode = call(self.create_corefile + " main-bin-spec " + self.binspec_corefile + " " + self.aout_exe + " 0xffffffffffffffff", shell=True)
-        retcode = call(self.create_corefile + " main-bin-spec " + self.binspec_corefile_addr + " " + self.aout_exe + (" 0x%x" % self.slide), shell=True)
-
-    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
-    @skipIf(archs=no_match(['x86_64']))
-    @skipUnlessDarwin
-    def test_lc_note_version_string(self):
-        self.initial_setup()
-
-        if self.TraceOn():
-            self.runCmd("log enable lldb dyld host")
-            self.addTearDownHook(lambda: self.runCmd("log disable lldb dyld host"))
+        os.chmod(dsym_for_uuid, 0o755)
 
         ### Now run lldb on the corefile
         ### which will give us a UUID
         ### which we call dsym-for-uuid.sh with
         ### which gives us a binary and dSYM
         ### which lldb should load!
 
-        # First, try the "kern ver str" corefile
-        self.target = self.dbg.CreateTarget('')
-        err = lldb.SBError()
-        if self.TraceOn():
-            self.runCmd("script print('loading corefile %s')" % self.verstr_corefile)
-        self.process = self.target.LoadCore(self.verstr_corefile)
-        self.assertEqual(self.process.IsValid(), True)
-        if self.TraceOn():
-            self.runCmd("image list")
-            self.runCmd("target mod dump sections")
-        self.assertEqual(self.target.GetNumModules(), 1)
-        fspec = self.target.GetModuleAtIndex(0).GetFileSpec()
-        self.assertEqual(fspec.GetFilename(), self.aout_exe_basename)
-        self.process.Kill()
-        self.process = None
-        self.target.Clear()
-        self.target = None
-        self.dbg.MemoryPressureDetected()
-
-        # Second, try the "kern ver str" corefile where it loads at an address
-        self.target = self.dbg.CreateTarget('')
-        err = lldb.SBError()
-        if self.TraceOn():
-            self.runCmd("script print('loading corefile %s')" % self.verstr_corefile_addr)
-        self.process = self.target.LoadCore(self.verstr_corefile_addr)
-        self.assertEqual(self.process.IsValid(), True)
-        if self.TraceOn():
-            self.runCmd("image list")
-            self.runCmd("target mod dump sections")
-        self.assertEqual(self.target.GetNumModules(), 1)
-        fspec = self.target.GetModuleAtIndex(0).GetFileSpec()
-        self.assertEqual(fspec.GetFilename(), self.aout_exe_basename)
-        main_sym = self.target.GetModuleAtIndex(0).FindSymbol("main", lldb.eSymbolTypeAny)
-        main_addr = main_sym.GetStartAddress()
-        self.assertGreater(main_addr.GetLoadAddress(self.target), self.slide)
-        self.assertNotEqual(main_addr.GetLoadAddress(self.target), lldb.LLDB_INVALID_ADDRESS)
-        self.process.Kill()
-        self.process = None
-        self.target.Clear()
-        self.target = None
-        self.dbg.MemoryPressureDetected()
-
-    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
-    @skipIf(archs=no_match(['x86_64']))
-    @skipUnlessDarwin
-    def test_lc_note_main_bin_spec(self):
-        self.initial_setup()
-
-        if self.TraceOn():
-            self.runCmd("log enable lldb dyld host")
-            self.addTearDownHook(lambda: self.runCmd("log disable lldb dyld host"))
-
-        # Third, try the "main bin spec" corefile
-        self.target = self.dbg.CreateTarget('')
-        if self.TraceOn():
-            self.runCmd("script print('loading corefile %s')" % self.binspec_corefile)
-        self.process = self.target.LoadCore(self.binspec_corefile)
-        self.assertEqual(self.process.IsValid(), True)
-        if self.TraceOn():
-            self.runCmd("image list")
-            self.runCmd("target mod dump sections")
-        self.assertEqual(self.target.GetNumModules(), 1)
-        fspec = self.target.GetModuleAtIndex(0).GetFileSpec()
-        self.assertEqual(fspec.GetFilename(), self.aout_exe_basename)
-        self.process.Kill()
-        self.process = None
-        self.target.Clear()
-        self.target = None
-        self.dbg.MemoryPressureDetected()
-
-        # Fourth, try the "main bin spec" corefile where it loads at an address
-        self.target = self.dbg.CreateTarget('')
-        if self.TraceOn():
-            self.runCmd("script print('loading corefile %s')" % self.binspec_corefile_addr)
-        self.process = self.target.LoadCore(self.binspec_corefile_addr)
-        self.assertEqual(self.process.IsValid(), True)
-        if self.TraceOn():
-            self.runCmd("image list")
-            self.runCmd("target mod dump sections")
-        self.assertEqual(self.target.GetNumModules(), 1)
-        fspec = self.target.GetModuleAtIndex(0).GetFileSpec()
-        self.assertEqual(fspec.GetFilename(), self.aout_exe_basename)
-        main_sym = self.target.GetModuleAtIndex(0).FindSymbol("main", lldb.eSymbolTypeAny)
-        main_addr = main_sym.GetStartAddress()
-        self.assertGreater(main_addr.GetLoadAddress(self.target), self.slide)
-        self.assertNotEqual(main_addr.GetLoadAddress(self.target), lldb.LLDB_INVALID_ADDRESS)
-        self.process.Kill()
-        self.process = None
-        self.target.Clear()
-        self.target = None
-        self.dbg.MemoryPressureDetected()
-
-    @skipIf(debug_info=no_match(["dsym"]), bugnumber="This test is looking explicitly for a dSYM")
-    @skipIf(archs=no_match(['x86_64']))
-    @skipUnlessDarwin
-    def test_lc_note_main_bin_spec_os_plugin(self):
-        self.initial_setup()
-
         if self.TraceOn():
             self.runCmd("log enable lldb dyld host")
             self.addTearDownHook(lambda: self.runCmd("log disable lldb dyld host"))
         # Now load the binary and confirm that we load the OS plugin.
-        self.target = self.dbg.CreateTarget('')
+        target = self.dbg.CreateTarget('')
 
         if self.TraceOn():
-            self.runCmd("script print('loading corefile %s with OS plugin')" % self.binspec_corefile_addr)
-        self.process = self.target.LoadCore(self.binspec_corefile_addr)
-        self.assertEqual(self.process.IsValid(), True)
+            self.runCmd("script print('loading corefile %s with OS plugin')" % binspec_corefile_addr)
+
+        process = target.LoadCore(binspec_corefile_addr)
+        self.assertEqual(process.IsValid(), True)
         if self.TraceOn():
             self.runCmd("image list")
             self.runCmd("target mod dump sections")
             self.runCmd("thread list")
-        self.assertEqual(self.target.GetNumModules(), 1)
-        fspec = self.target.GetModuleAtIndex(0).GetFileSpec()
-        self.assertEqual(fspec.GetFilename(), self.aout_exe_basename)
+        self.assertEqual(target.GetNumModules(), 1)
+        fspec = target.GetModuleAtIndex(0).GetFileSpec()
+        self.assertEqual(fspec.GetFilename(), aout_exe_basename)
 
         # Verify our OS plug-in threads showed up
-        thread = self.process.GetThreadByID(0x111111111)
+        thread = process.GetThreadByID(0x111111111)
         self.assertTrue(thread.IsValid(), 
                 "Make sure there is a thread 0x111111111 after we load the python OS plug-in")
-        thread = self.process.GetThreadByID(0x222222222)
+        thread = process.GetThreadByID(0x222222222)
         self.assertTrue(thread.IsValid(), 
                 "Make sure there is a thread 0x222222222 after we load the python OS plug-in")
-        thread = self.process.GetThreadByID(0x333333333)
+        thread = process.GetThreadByID(0x333333333)
         self.assertTrue(thread.IsValid(), 
                 "Make sure there is a thread 0x333333333 after we load the python OS plug-in")
 
-        self.process.Kill()
-        self.process = None
-        self.target.Clear()
-        self.target = None
-        self.dbg.MemoryPressureDetected()
+        self.runCmd("settings clear target.process.python-os-plugin-path")
+        self.dbg.DeleteTarget(target)

lldb/test/API/macosx/lc-note/firmware-corefile/create-empty-corefile.cpp

 // the UUID from that binary will be encoded in the corefile.
 // Otherwise a pre-set UUID will be put in the corefile that
 // is created.
 
 struct main_bin_spec_payload {
   uint32_t version;
   uint32_t type;
   uint64_t address;
+  uint64_t slide;
   uuid_t uuid;
   uint32_t log2_pagesize;
-  uint32_t unused;
+  uint32_t platform;
 };
 
 union uint32_buf {
   uint8_t bytebuf[4];
   uint32_t val;
 };
 
 union uint64_buf {

 
 void add_uint32(std::vector<uint8_t> &buf, uint32_t val) {
   uint32_buf conv;
   conv.val = val;
   for (int i = 0; i < 4; i++)
     buf.push_back(conv.bytebuf[i]);
 }
 
-std::vector<uint8_t> x86_lc_thread_load_command() {
+std::vector<uint8_t> lc_thread_load_command(cpu_type_t cputype) {
   std::vector<uint8_t> data;
-  add_uint32(data, LC_THREAD);                // thread_command.cmd
-  add_uint32(data, 184);                      // thread_command.cmdsize
-  add_uint32(data, x86_THREAD_STATE64);       // thread_command.flavor
-  add_uint32(data, x86_THREAD_STATE64_COUNT); // thread_command.count
-  add_uint64(data, 0x0000000000000000);       // rax
-  add_uint64(data, 0x0000000000000400);       // rbx
-  add_uint64(data, 0x0000000000000000);       // rcx
-  add_uint64(data, 0x0000000000000000);       // rdx
-  add_uint64(data, 0x0000000000000000);       // rdi
-  add_uint64(data, 0x0000000000000000);       // rsi
-  add_uint64(data, 0xffffff9246e2ba20);       // rbp
-  add_uint64(data, 0xffffff9246e2ba10);       // rsp
-  add_uint64(data, 0x0000000000000000);       // r8
-  add_uint64(data, 0x0000000000000000);       // r9
-  add_uint64(data, 0x0000000000000000);       // r10
-  add_uint64(data, 0x0000000000000000);       // r11
-  add_uint64(data, 0xffffff7f96ce5fe1);       // r12
-  add_uint64(data, 0x0000000000000000);       // r13
-  add_uint64(data, 0x0000000000000000);       // r14
-  add_uint64(data, 0xffffff9246e2bac0);       // r15
-  add_uint64(data, 0xffffff8015a8f6d0);       // rip
-  add_uint64(data, 0x0000000000011111);       // rflags
-  add_uint64(data, 0x0000000000022222);       // cs
-  add_uint64(data, 0x0000000000033333);       // fs
-  add_uint64(data, 0x0000000000044444);       // gs
+  // Emit an LC_THREAD register context appropriate for the cputype
+  // of the binary we're embedded.  The tests in this case do not
+  // use the register values, so 0's are fine, lldb needs to see at
+  // least one LC_THREAD in the corefile.
+#if defined(__x86_64__)
+  if (cputype == CPU_TYPE_X86_64) {
+    add_uint32(data, LC_THREAD); // thread_command.cmd
+    add_uint32(data,
+               16 + (x86_THREAD_STATE64_COUNT * 4)); // thread_command.cmdsize
+    add_uint32(data, x86_THREAD_STATE64);            // thread_command.flavor
+    add_uint32(data, x86_THREAD_STATE64_COUNT);      // thread_command.count
+    for (int i = 0; i < x86_THREAD_STATE64_COUNT; i++) {
+      add_uint32(data, 0); // whatever, just some empty register values
+    }
+  }
+#endif
+#if defined(__arm64__) || defined(__aarch64__)
+  if (cputype == CPU_TYPE_ARM64) {
+    add_uint32(data, LC_THREAD); // thread_command.cmd
+    add_uint32(data,
+               16 + (ARM_THREAD_STATE64_COUNT * 4)); // thread_command.cmdsize
+    add_uint32(data, ARM_THREAD_STATE64);            // thread_command.flavor
+    add_uint32(data, ARM_THREAD_STATE64_COUNT);      // thread_command.count
+    for (int i = 0; i < ARM_THREAD_STATE64_COUNT; i++) {
+      add_uint32(data, 0); // whatever, just some empty register values
+    }
+  }
+#endif
   return data;
 }
 
 void add_lc_note_kern_ver_str_load_command(
     std::vector<std::vector<uint8_t>> &loadcmds, std::vector<uint8_t> &payload,
     int payload_file_offset, std::string uuid, uint64_t address) {
   std::string ident = "EFI UUID=";
   ident += uuid;
void add_lc_note_kern_ver_str_load_command(
   add_uint32(payload, 1); // kerneL_version_string.version
   for (int i = 0; i < ident.size() + 1; i++) {
     payload.push_back(ident[i]);
   }
 }
 
 void add_lc_note_main_bin_spec_load_command(
     std::vector<std::vector<uint8_t>> &loadcmds, std::vector<uint8_t> &payload,
-    int payload_file_offset, std::string uuidstr, uint64_t address) {
+    int payload_file_offset, std::string uuidstr, uint64_t address,
+    uint64_t slide) {
   std::vector<uint8_t> loadcmd_data;
 
   add_uint32(loadcmd_data, LC_NOTE); // note_command.cmd
   add_uint32(loadcmd_data, 40);      // note_command.cmdsize
   char lc_note_name[16];
   memset(lc_note_name, 0, 16);
   strcpy(lc_note_name, "main bin spec");
 
   // lc_note.data_owner
   for (int i = 0; i < 16; i++)
     loadcmd_data.push_back(lc_note_name[i]);
 
   // we start writing the payload at payload_file_offset to leave
   // room at the start for the header & the load commands.
   uint64_t current_payload_offset = payload.size() + payload_file_offset;
 
   add_uint64(loadcmd_data, current_payload_offset); // note_command.offset
   add_uint64(loadcmd_data,
              sizeof(struct main_bin_spec_payload)); // note_command.size
 
   loadcmds.push_back(loadcmd_data);
 
   // Now write the "main bin spec" payload.
-  add_uint32(payload, 1);          // version
+  add_uint32(payload, 2);          // version
   add_uint32(payload, 3);          // type == 3 [ firmware, standalone, etc ]
   add_uint64(payload, address);    // load address
+  add_uint64(payload, slide);      // slide
   uuid_t uuid;
   uuid_parse(uuidstr.c_str(), uuid);
   for (int i = 0; i < sizeof(uuid_t); i++)
     payload.push_back(uuid[i]);
   add_uint32(payload, 0); // log2_pagesize unspecified
-  add_uint32(payload, 0); // unused
+  add_uint32(payload, 0); // platform unspecified
 }
 
 void add_lc_segment(std::vector<std::vector<uint8_t>> &loadcmds,
                     std::vector<uint8_t> &payload, int payload_file_offset) {
   std::vector<uint8_t> loadcmd_data;
   struct segment_command_64 seg;
   seg.cmd = LC_SEGMENT_64;
   seg.cmdsize = sizeof(struct segment_command_64); // no sections
void add_lc_segment(std::vector<std::vector<uint8_t>> &loadcmds,
 
   uint8_t *p = (uint8_t *)&seg;
   for (int i = 0; i < sizeof(struct segment_command_64); i++) {
     loadcmd_data.push_back(*(p + i));
   }
   loadcmds.push_back(loadcmd_data);
 }
 
-std::string get_uuid_from_binary(const char *fn) {
+std::string get_uuid_from_binary(const char *fn, cpu_type_t &cputype,
+                                 cpu_subtype_t &cpusubtype) {
   FILE *f = fopen(fn, "r");
   if (f == nullptr) {
     fprintf(stderr, "Unable to open binary '%s' to get uuid\n", fn);
     exit(1);
   }
   uint32_t num_of_load_cmds = 0;
   uint32_t size_of_load_cmds = 0;
   std::string uuid;
std::string get_uuid_from_binary(const char *fn, cpu_type_t &cputype,
 
   ::fseeko(f, 0, SEEK_SET);
   if (memcmp(magic, magic_32_le, 4) == 0) {
     struct mach_header mh;
     if (::fread(&mh, 1, sizeof(mh), f) != sizeof(mh)) {
       fprintf(stderr, "error reading mach header from input file\n");
       exit(1);
     }
-    if (mh.cputype != CPU_TYPE_X86_64) {
+    if (mh.cputype != CPU_TYPE_X86_64 && mh.cputype != CPU_TYPE_ARM64) {
       fprintf(stderr,
-              "This tool creates an x86_64 corefile but "
+              "This tool creates an x86_64/arm64 corefile but "
               "the supplied binary '%s' is cputype 0x%x\n",
               fn, (uint32_t)mh.cputype);
       exit(1);
     }
     num_of_load_cmds = mh.ncmds;
     size_of_load_cmds = mh.sizeofcmds;
     file_offset += sizeof(struct mach_header);
+    cputype = mh.cputype;
+    cpusubtype = mh.cpusubtype;
   } else {
     struct mach_header_64 mh;
     if (::fread(&mh, 1, sizeof(mh), f) != sizeof(mh)) {
       fprintf(stderr, "error reading mach header from input file\n");
       exit(1);
     }
-    if (mh.cputype != CPU_TYPE_X86_64) {
+    if (mh.cputype != CPU_TYPE_X86_64 && mh.cputype != CPU_TYPE_ARM64) {
       fprintf(stderr,
-              "This tool creates an x86_64 corefile but "
+              "This tool creates an x86_64/arm64 corefile but "
               "the supplied binary '%s' is cputype 0x%x\n",
               fn, (uint32_t)mh.cputype);
       exit(1);
     }
     num_of_load_cmds = mh.ncmds;
     size_of_load_cmds = mh.sizeofcmds;
     file_offset += sizeof(struct mach_header_64);
+    cputype = mh.cputype;
+    cpusubtype = mh.cpusubtype;
   }
 
   off_t load_cmds_offset = file_offset;
 
   for (int i = 0; i < num_of_load_cmds &&
                   (file_offset - load_cmds_offset) < size_of_load_cmds;
        i++) {
     ::fseeko(f, file_offset, SEEK_SET);
if (cmd == LC_UUID) {
       break;
     }
     file_offset += cmdsize;
   }
   return uuid;
 }
 
 int main(int argc, char **argv) {
-  if (argc != 5) {
-    fprintf(stderr,
-            "usage: create-empty-corefile version-string|main-bin-spec "
-            "<output-core-name> <binary-to-copy-uuid-from> <address>\n");
+  if (argc != 6) {
+    fprintf(
+        stderr,
+        "<output-core-name> <binary-to-copy-uuid-from> <address> <slide>\n");
     fprintf(stderr,
             "     <address> is base 16, 0xffffffffffffffff means unknown\n");
+    fprintf(stderr,
+            "     <slide> is base 16, 0xffffffffffffffff means unknown\n");
     fprintf(
         stderr,
         "Create a Mach-O corefile with an either LC_NOTE 'kern ver str' or \n");
     fprintf(stderr, "an LC_NOTE 'main bin spec' load command without an "
                     "address specified, depending on\n");
     fprintf(stderr, "whether the 1st arg is version-string or main-bin-spec\n");
     exit(1);
   }
   if (strcmp(argv[1], "version-string") != 0 &&
       strcmp(argv[1], "main-bin-spec") != 0) {
     fprintf(stderr, "arg1 was not version-string or main-bin-spec\n");
     exit(1);
   }
 
-  std::string uuid = get_uuid_from_binary(argv[3]);
+  cpu_type_t cputype;
+  cpu_subtype_t cpusubtype;
+  std::string uuid = get_uuid_from_binary(argv[3], cputype, cpusubtype);
 
   // An array of load commands (in the form of byte arrays)
   std::vector<std::vector<uint8_t>> load_commands;
 
   // An array of corefile contents (page data, lc_note data, etc)
   std::vector<uint8_t> payload;
 
   errno = 0;
   uint64_t address = strtoull(argv[4], NULL, 16);
   if (errno != 0) {
     fprintf(stderr, "Unable to parse address %s as base 16", argv[4]);
     exit(1);
   }
 
+  errno = 0;
+  uint64_t slide = strtoull(argv[5], NULL, 16);
+  if (errno != 0) {
+    fprintf(stderr, "Unable to parse slide %s as base 16", argv[4]);
+    exit(1);
+  }
+
   // First add all the load commands / payload so we can figure out how large
   // the load commands will actually be.
-  load_commands.push_back(x86_lc_thread_load_command());
+  load_commands.push_back(lc_thread_load_command(cputype));
   if (strcmp(argv[1], "version-string") == 0)
     add_lc_note_kern_ver_str_load_command(load_commands, payload, 0, uuid,
                                           address);
   else
     add_lc_note_main_bin_spec_load_command(load_commands, payload, 0, uuid,
-                                           address);
+                                           address, slide);
   add_lc_segment(load_commands, payload, 0);
 
   int size_of_load_commands = 0;
   for (const auto &lc : load_commands)
     size_of_load_commands += lc.size();
 
   int header_and_load_cmd_room =
       sizeof(struct mach_header_64) + size_of_load_commands;
 
   // Erase the load commands / payload now that we know how much space is
   // needed, redo it.
   load_commands.clear();
   payload.clear();
 
-  load_commands.push_back(x86_lc_thread_load_command());
+  load_commands.push_back(lc_thread_load_command(cputype));
 
   if (strcmp(argv[1], "version-string") == 0)
     add_lc_note_kern_ver_str_load_command(
         load_commands, payload, header_and_load_cmd_room, uuid, address);
   else
     add_lc_note_main_bin_spec_load_command(
-        load_commands, payload, header_and_load_cmd_room, uuid, address);
+        load_commands, payload, header_and_load_cmd_room, uuid, address, slide);
 
   add_lc_segment(load_commands, payload, header_and_load_cmd_room);
 
   struct mach_header_64 mh;
   mh.magic = MH_MAGIC_64;
-  mh.cputype = CPU_TYPE_X86_64;
+  mh.cputype = cputype;
 
-  mh.cpusubtype = CPU_SUBTYPE_X86_64_ALL;
+  mh.cpusubtype = cpusubtype;
   mh.filetype = MH_CORE;
   mh.ncmds = load_commands.size();
   mh.sizeofcmds = size_of_load_commands;
   mh.flags = 0;
   mh.reserved = 0;
 
   FILE *f = fopen(argv[2], "w");