diff --git a/CMakeLists.txt b/CMakeLists.txt
index cfae0f8b74b..32a737cfb02 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -318,17 +318,6 @@ if(EXECUTORCH_SRCS_FILE)
   )
 endif()
 executorch_load_build_variables()
-if(NOT EXECUTORCH_SRCS_FILE)
-  # A file wasn't provided. Run a script to extract the source lists from the
-  # buck2 build system and write them to a file we can include.
-  #
-  # NOTE: This will only happen once during cmake setup, so it will not re-run
-  # if the buck2 targets change.
-  message(STATUS "executorch: Generating source lists")
-  set(EXECUTORCH_SRCS_FILE "${CMAKE_CURRENT_BINARY_DIR}/executorch_srcs.cmake")
-  extract_sources(${EXECUTORCH_SRCS_FILE})
-  executorch_validate_build_variables()
-endif()
 
 # Detect if an iOS toolchain is set.
 if(CMAKE_TOOLCHAIN_FILE MATCHES ".*(iOS|ios\.toolchain)\.cmake$")
diff --git a/tools/cmake/Codegen.cmake b/tools/cmake/Codegen.cmake
index 93ba0f890a8..aa9c2133851 100644
--- a/tools/cmake/Codegen.cmake
+++ b/tools/cmake/Codegen.cmake
@@ -378,139 +378,73 @@ function(executorch_append_filelist name outputvar)
   )
 endfunction()
 
-set(EXECUTORCH_BUILD_VARIABLES_FILELISTS
-    EXECUTORCH_SRCS
-    EXECUTORCH_CORE_SRCS
-    PORTABLE_KERNELS_SRCS
-    KERNELS_UTIL_ALL_DEPS_SRCS
-    OPTIMIZED_KERNELS_SRCS
-    QUANTIZED_KERNELS_SRCS
-    PROGRAM_SCHEMA_SRCS
-    OPTIMIZED_CPUBLAS_SRCS
-    OPTIMIZED_NATIVE_CPU_OPS_SRCS
-    TEST_BACKEND_COMPILER_LIB_SRCS
-    EXTENSION_DATA_LOADER_SRCS
-    EXTENSION_EVALUE_UTIL_SRCS
-    EXTENSION_FLAT_TENSOR_SRCS
-    EXTENSION_MODULE_SRCS
-    EXTENSION_RUNNER_UTIL_SRCS
-    EXTENSION_LLM_RUNNER_SRCS
-    EXTENSION_TENSOR_SRCS
-    EXTENSION_THREADPOOL_SRCS
-    EXTENSION_TRAINING_SRCS
-    TRAIN_XOR_SRCS
-    EXECUTOR_RUNNER_SRCS
-    SIZE_TEST_SRCS
-    MPS_EXECUTOR_RUNNER_SRCS
-    MPS_BACKEND_SRCS
-    MPS_SCHEMA_SRCS
-    XNN_EXECUTOR_RUNNER_SRCS
-    XNNPACK_BACKEND_SRCS
-    XNNPACK_SCHEMA_SRCS
-    VULKAN_SCHEMA_SRCS
-    CUSTOM_OPS_SRCS
-    LLAMA_RUNNER_SRCS
-)
-set(EXECUTORCH_BUILD_VARIABLES_VARNAMES
-    _executorch__srcs
-    _executorch_core__srcs
-    _portable_kernels__srcs
-    _kernels_util_all_deps__srcs
-    _optimized_kernels__srcs
-    _quantized_kernels__srcs
-    _program_schema__srcs
-    _optimized_cpublas__srcs
-    _optimized_native_cpu_ops__srcs
-    _test_backend_compiler_lib__srcs
-    _extension_data_loader__srcs
-    _extension_evalue_util__srcs
-    _extension_flat_tensor__srcs
-    _extension_module__srcs
-    _extension_runner_util__srcs
-    _extension_llm_runner__srcs
-    _extension_tensor__srcs
-    _extension_threadpool__srcs
-    _extension_training__srcs
-    _train_xor__srcs
-    _executor_runner__srcs
-    _size_test__srcs
-    _mps_executor_runner__srcs
-    _mps_backend__srcs
-    _mps_schema__srcs
-    _xnn_executor_runner__srcs
-    _xnnpack_backend__srcs
-    _xnnpack_schema__srcs
-    _vulkan_schema__srcs
-    _custom_ops__srcs
-    _llama_runner__srcs
-)
-
-# Fail the build if the src lists in build_variables.bzl do not match the src
-# lists extracted from Buck and placed into EXECUTORCH_SRCS_FILE. This is
-# intended to be a safety mechanism while we are in the process of removing Buck
-# from the CMake build and replacing it with build_variables.bzl; if you are
-# seeing failures after you have intentionally changed Buck srcs, then simply
-# update build_variables.bzl. If you are seeing failures after changing
-# something about the build system, make sure your changes will work both before
-# and after we finish replacing Buck with build_variables.bzl, which should
-# involve getting these lists to match!
-function(executorch_validate_build_variables)
-  include(${EXECUTORCH_SRCS_FILE})
-  foreach(filelist_and_varname IN
-          ZIP_LISTS EXECUTORCH_BUILD_VARIABLES_FILELISTS
-          EXECUTORCH_BUILD_VARIABLES_VARNAMES
-  )
-    executorch_append_filelist(
-      ${filelist_and_varname_0}
-      "${filelist_and_varname_1}_from_build_variables"
-    )
-    # The Buck and CMake mechanisms for getting the default PAL set up are
-    # different. Prevent the Buck choice from flowing into CMake and causing
-    # validation to fail, just like we do in our CMakeLists.txt.
-    if("${filelist_and_varname_1}" STREQUAL "_executorch_core__srcs")
-      list(FILTER ${filelist_and_varname_1} EXCLUDE REGEX
-           "runtime/platform/default/[^/]*.cpp$"
-      )
-    endif()
-    if(NOT ${filelist_and_varname_1} STREQUAL
-       ${filelist_and_varname_1}_from_build_variables
-    )
-      set(generated_items_not_in_build_variables ${${filelist_and_varname_1}})
-      list(REMOVE_ITEM generated_items_not_in_build_variables
-           ${${filelist_and_varname_1}_from_build_variables}
-      )
-
-      set(build_variables_items_not_in_generated
-          ${${filelist_and_varname_1}_from_build_variables}
-      )
-      list(REMOVE_ITEM build_variables_items_not_in_generated
-           ${${filelist_and_varname_1}}
-      )
-
-      list(JOIN generated_items_not_in_build_variables "\n"
-           pretty_generated_items_not_in_build_variables
-      )
-      list(JOIN build_variables_items_not_in_generated "\n"
-           pretty_build_variables_items_not_in_generated
-      )
-      if(NOT pretty_generated_items_not_in_build_variables)
-        set(pretty_generated_items_not_in_build_variables "<none>")
-      endif()
-      if(NOT pretty_build_variables_items_not_in_generated)
-        set(pretty_build_variables_items_not_in_generated "<none>")
-      endif()
-      message(
-        FATAL_ERROR
-          "Buck-generated ${filelist_and_varname_1} does not match hardcoded "
-          "${filelist_and_varname_0} in build_variables.bzl. Buck-generated items not in build_variables.bzl: "
-          "${pretty_generated_items_not_in_build_variables}\n "
-          "build_variables.bzl items not in buck-generated list: ${pretty_build_variables_items_not_in_generated}"
-      )
-    endif()
-  endforeach()
-endfunction()
-
 function(executorch_load_build_variables)
+  set(EXECUTORCH_BUILD_VARIABLES_FILELISTS
+      EXECUTORCH_SRCS
+      EXECUTORCH_CORE_SRCS
+      PORTABLE_KERNELS_SRCS
+      KERNELS_UTIL_ALL_DEPS_SRCS
+      OPTIMIZED_KERNELS_SRCS
+      QUANTIZED_KERNELS_SRCS
+      PROGRAM_SCHEMA_SRCS
+      OPTIMIZED_CPUBLAS_SRCS
+      OPTIMIZED_NATIVE_CPU_OPS_SRCS
+      TEST_BACKEND_COMPILER_LIB_SRCS
+      EXTENSION_DATA_LOADER_SRCS
+      EXTENSION_EVALUE_UTIL_SRCS
+      EXTENSION_FLAT_TENSOR_SRCS
+      EXTENSION_MODULE_SRCS
+      EXTENSION_RUNNER_UTIL_SRCS
+      EXTENSION_LLM_RUNNER_SRCS
+      EXTENSION_TENSOR_SRCS
+      EXTENSION_THREADPOOL_SRCS
+      EXTENSION_TRAINING_SRCS
+      TRAIN_XOR_SRCS
+      EXECUTOR_RUNNER_SRCS
+      SIZE_TEST_SRCS
+      MPS_EXECUTOR_RUNNER_SRCS
+      MPS_BACKEND_SRCS
+      MPS_SCHEMA_SRCS
+      XNN_EXECUTOR_RUNNER_SRCS
+      XNNPACK_BACKEND_SRCS
+      XNNPACK_SCHEMA_SRCS
+      VULKAN_SCHEMA_SRCS
+      CUSTOM_OPS_SRCS
+      LLAMA_RUNNER_SRCS
+  )
+  set(EXECUTORCH_BUILD_VARIABLES_VARNAMES
+      _executorch__srcs
+      _executorch_core__srcs
+      _portable_kernels__srcs
+      _kernels_util_all_deps__srcs
+      _optimized_kernels__srcs
+      _quantized_kernels__srcs
+      _program_schema__srcs
+      _optimized_cpublas__srcs
+      _optimized_native_cpu_ops__srcs
+      _test_backend_compiler_lib__srcs
+      _extension_data_loader__srcs
+      _extension_evalue_util__srcs
+      _extension_flat_tensor__srcs
+      _extension_module__srcs
+      _extension_runner_util__srcs
+      _extension_llm_runner__srcs
+      _extension_tensor__srcs
+      _extension_threadpool__srcs
+      _extension_training__srcs
+      _train_xor__srcs
+      _executor_runner__srcs
+      _size_test__srcs
+      _mps_executor_runner__srcs
+      _mps_backend__srcs
+      _mps_schema__srcs
+      _xnn_executor_runner__srcs
+      _xnnpack_backend__srcs
+      _xnnpack_schema__srcs
+      _vulkan_schema__srcs
+      _custom_ops__srcs
+      _llama_runner__srcs
+  )
   foreach(filelist_and_varname IN
           ZIP_LISTS EXECUTORCH_BUILD_VARIABLES_FILELISTS
           EXECUTORCH_BUILD_VARIABLES_VARNAMES