diff --git a/src/cmd/cos_kernel_devenv/devenv.sh b/src/cmd/cos_kernel_devenv/devenv.sh
index 3c2044d..662f3ce 100755
--- a/src/cmd/cos_kernel_devenv/devenv.sh
+++ b/src/cmd/cos_kernel_devenv/devenv.sh
@@ -248,32 +248,39 @@ install_build_cross_toolchain() {
   local -r tc_url_file_path="${bucket}/${TOOLCHAIN_URL_FILENAME}"
-
+
   info "Obtaining toolchain_env file from ${tc_env_file_path}"
-
+
   # Download toolchain_env if present
   if ! download_from_gcs "${tc_env_file_path}" "${BUILD_DIR}/${TOOLCHAIN_ENV_FILENAME}"; then
         error "Failed to download toolchain file"
         error "Make sure build id '$RELEASE_ID' is valid"
         return ${RETCODE_ERROR}
   fi
-
+
-  # Download toolchain_path if present
-  if ! download_from_gcs "${tc_url_file_path}" "${BUILD_DIR}/${TOOLCHAIN_URL_FILENAME}"; then
-        error "Failed to download toolchain file"
-        error "Make sure build id '$RELEASE_ID' is valid"
-        return ${RETCODE_ERROR}
-  fi
+  # Custom COS buckets normally publish toolchain_path, but the public GKE
+  # Arm release directory publishes the same descriptor as
+  # toolchain.tar.xz.gcs. Accept both official layouts.
+  if download_from_gcs "${tc_url_file_path}" "${BUILD_DIR}/${TOOLCHAIN_URL_FILENAME}"; then
+    local -r tc_path="$(cat ${BUILD_DIR}/${TOOLCHAIN_URL_FILENAME})"
+    local tc_download_url="${COS_TC_DOWNLOAD_GCS}${tc_path}"
+    if ! gcloud storage -q ls "${tc_download_url}"; then
+      tc_download_url="${CROS_TC_DOWNLOAD_GCS}${tc_path}"
+    fi
-
+
-  local -r tc_path="$(cat ${BUILD_DIR}/${TOOLCHAIN_URL_FILENAME})"
-  local tc_download_url="${COS_TC_DOWNLOAD_GCS}${tc_path}"
-  if ! gcloud storage -q ls "${tc_download_url}"; then
-    tc_download_url="${CROS_TC_DOWNLOAD_GCS}${tc_path}"
-  fi
+    if ! gcloud storage -q ls "${tc_download_url}"; then
+          error "Toolchain path '${tc_path}' does not exist in either COS or CrOS GCS buckets"
+          return ${RETCODE_ERROR}
+    fi
+  else
+    local -r tc_gcs_download_url="${bucket}/${TOOLCHAIN_ARCHIVE_GCS}"
+    if ! download_from_gcs "${tc_gcs_download_url}" "${BUILD_DIR}/${TOOLCHAIN_ARCHIVE_GCS}"; then
+          error "Neither toolchain_path nor toolchain.tar.xz.gcs exists"
+          return ${RETCODE_ERROR}
+    fi
+    local -r tc_bucket=$(grep '^bucket:' "${BUILD_DIR}/${TOOLCHAIN_ARCHIVE_GCS}" | cut -d ' ' -f 2)
+    local -r tc_object=$(grep '^path:' "${BUILD_DIR}/${TOOLCHAIN_ARCHIVE_GCS}" | cut -d ' ' -f 2)
+    local -r tc_download_url="gs://${tc_bucket}/${tc_object}"
+  fi
-
+
-  if ! gcloud storage -q ls "${tc_download_url}"; then
-        error "Toolchain path '${tc_path}' does not exist in either COS or CrOS GCS buckets"
-        return ${RETCODE_ERROR}
-  fi
-
   # Install toolchain pkg
   install_cross_toolchain_pkg "${tc_download_url}"
 }