nixos/systemd-boot: Support extra EFI entries

nixos/modules/system/boot/loader/systemd-boot/systemd-boot-builder.py

@@ -45,16 +45,6 @@ initrd {initrd}
 options {kernel_params}
 """
 
-# The boot loader entry for memtest86.
-#
-# TODO: This is hard-coded to use the 64-bit EFI app, but it could probably
-# be updated to use the 32-bit EFI app on 32-bit systems.  The 32-bit EFI
-# app filename is BOOTIA32.efi.
-MEMTEST_BOOT_ENTRY = """title MemTest86
-efi /efi/memtest86/BOOTX64.efi
-"""
-
-
 def generation_conf_filename(profile: Optional[str], generation: int, specialisation: Optional[str]) -> str:
     pieces = [
         "nixos",
@@ -283,23 +273,24 @@ def main() -> None:
         except OSError as e:
             print("ignoring profile '{}' in the list of boot entries because of the following error:\n{}".format(profile, e), file=sys.stderr)
 
-    memtest_entry_file = "@efiSysMountPoint@/loader/entries/memtest86.conf"
-    if os.path.exists(memtest_entry_file):
-        os.unlink(memtest_entry_file)
-    shutil.rmtree("@efiSysMountPoint@/efi/memtest86", ignore_errors=True)
-    if "@memtest86@" != "":
-        mkdir_p("@efiSysMountPoint@/efi/memtest86")
-        for path in glob.iglob("@memtest86@/*"):
-            if os.path.isdir(path):
-                shutil.copytree(path, os.path.join("@efiSysMountPoint@/efi/memtest86", os.path.basename(path)))
-            else:
-                shutil.copy(path, "@efiSysMountPoint@/efi/memtest86/")
+    for root, _, files in os.walk('@efiSysMountPoint@/efi/nixos/.extra-files', topdown=False):
+        relative_root = root.removeprefix("@efiSysMountPoint@/efi/nixos/.extra-files").removeprefix("/")
+        actual_root = os.path.join("@efiSysMountPoint@", relative_root)
 
-        memtest_entry_file = "@efiSysMountPoint@/loader/entries/memtest86.conf"
-        memtest_entry_file_tmp_path = "%s.tmp" % memtest_entry_file
-        with open(memtest_entry_file_tmp_path, 'w') as f:
-            f.write(MEMTEST_BOOT_ENTRY)
-        os.rename(memtest_entry_file_tmp_path, memtest_entry_file)
+        for file in files:
+            actual_file = os.path.join(actual_root, file)
+
+            if os.path.exists(actual_file):
+                os.unlink(actual_file)
+            os.unlink(os.path.join(root, file))
+
+        if not len(os.listdir(actual_root)):
+            os.rmdir(actual_root)
+        os.rmdir(root)
+
+    mkdir_p("@efiSysMountPoint@/efi/nixos/.extra-files")
+
+    subprocess.check_call("@copyExtraFiles@")
 
     # Since fat32 provides little recovery facilities after a crash,
     # it can leave the system in an unbootable state, when a crash/outage