add option to preserve NVRAM boot order

README.md

@@ -99,6 +99,7 @@ There are other options as well, as detailed below:
 |`-l`, `--loader`                           | Create a `systemd-boot`-compatible loader config.*     |
 |`-n`, `--no-loader`		                | Turns off creating the loader configuration.	         |
 |`-s`, `--stub`                             | Set up NVRAM entries for the copied kernel.            |
+|`--preserve-boot-order`                    | Do not change the boot order when updating NVRAM.      |
 |`-m`, `--manage-only`	                    | Don't set up any NVRAM entries.*                       |
 |`-f`, `--force-update`                     | Forcefully update the main loader.conf.**              |
 

bin/kernelstub

@@ -196,6 +196,13 @@ def main(options=None): # Do the thing
         help = 'Set up NVRAM entries for the copied kernel'
     )
 
+    parser.add_argument(
+        '--preserve-boot-order',
+        action = 'store_true',
+        dest = 'preserve_boot_order',
+        help = 'Do not change the boot order when updating NVRAM.'
+    )
+
     loader_stub.add_argument(
         '-m',
         '--manage-only',

kernelstub/application.py

@@ -248,6 +248,9 @@ def main(self, args): # Do the thing
         if args.manage_mode:
             configuration['manage_mode'] = True
 
+        if args.preserve_boot_order:
+            configuration['preserve_boot_order'] = True
+        preserve_boot_order = configuration["preserve_boot_order"] == True
 
         log.debug('Checking configuration integrity...')
         try:
@@ -315,6 +318,7 @@ def main(self, args): # Do the thing
             all_config = (
                 '   ESP Location:..................%s\n' % configuration['esp_path'] +
                 '   Management Mode:...............%s\n' % configuration['manage_mode'] +
+                '   Preserve NVRAM boot order (if not in management mode):..%s\n' % configuration['preserve_boot_order'] +
                 '   Install Loader configuration:..%s\n' % configuration['setup_loader'] +
                 '   Configuration version:.........%s\n' % configuration['config_rev'])
             log.info('Configuration details: \n\n%s' % all_config)
@@ -346,7 +350,7 @@ def main(self, args): # Do the thing
         installer.copy_cmdline(simulate=no_run)
 
         if not manage_mode:
-            installer.setup_stub(kopts, simulate=no_run)
+            installer.setup_stub(kopts, preserve_boot_order=preserve_boot_order, simulate=no_run)
 
         log.debug('Saving configuration to file')
 

kernelstub/config.py

@@ -37,9 +37,10 @@ class Config():
             'esp_path': "/boot/efi",
             'setup_loader': False,
             'manage_mode': False,
+            'preserve_boot_order': False,
             'force_update' : False,
             'live_mode' : False,
-            'config_rev' : 3
+            'config_rev' : 4
         }
     }
 
@@ -120,8 +121,11 @@ def update_config(self, config):
                 config['user']['kernel_options'] = self.parse_options(config['user']['kernel_options'].split())
             if type(config['default']['kernel_options']) is str:
                 config['default']['kernel_options'] = self.parse_options(config['default']['kernel_options'].split())
-        config['user']['config_rev'] = 3
-        config['default']['config_rev'] = 3
+        if config['user']['config_rev'] < 4:
+            config['user']['preserve_boot_order'] = False
+            config['default']['preserve_boot_order'] = False
+        config['user']['config_rev'] = 4
+        config['default']['config_rev'] = 4
         return config
 
     def parse_options(self, options):

kernelstub/installer.py

@@ -200,7 +200,7 @@ def setup_kernel(self, kernel_opts, setup_loader=False, overwrite=False, simulat
 
 
 
-    def setup_stub(self, kernel_opts, simulate=False):
+    def setup_stub(self, kernel_opts, preserve_boot_order=False, simulate=False):
         self.log.info("Setting up Kernel EFISTUB loader...")
         self.copy_cmdline(simulate=simulate)
         self.nvram.update()
@@ -212,7 +212,13 @@ def setup_stub(self, kernel_opts, simulate=False):
         else:
             self.log.debug("No old entry found, skipping removal.")
 
-        self.nvram.add_entry(self.opsys, self.drive, kernel_opts, simulate)
+        self.nvram.add_entry(
+            self.opsys,
+            self.drive,
+            kernel_opts,
+            preserve_boot_order=preserve_boot_order,
+            simulate=simulate
+        )
         self.nvram.update()
         nvram_lines = "\n".join(self.nvram.nvram)
         self.log.info('NVRAM configured, new values: \n\n%s\n' % nvram_lines)

kernelstub/nvram.py

@@ -69,16 +69,17 @@ def find_os_entry(self, nvram, os_label):
                 return find_index
 
 
-    def add_entry(self, this_os, this_drive, kernel_opts, simulate=False):
+    def add_entry(self, this_os, this_drive, kernel_opts, preserve_boot_order=False, simulate=False):
         self.log.info('Creating NVRAM entry')
+        create_cmd = "-c" if not preserve_boot_order else "-C"
         device = '/dev/%s' % this_drive.drive_name
         esp_num = this_drive.esp_num
         entry_label = '%s %s' % (this_os.name, this_os.version)
         entry_linux = '\\EFI\\%s-%s\\vmlinuz.efi' % (this_os.name, this_drive.root_uuid)
         entry_initrd = 'EFI/%s-%s/initrd.img' % (this_os.name, this_drive.root_uuid)
         command = [
             'efibootmgr',
-            '-c',
+            create_cmd,
             '-d', device,
             '-p', esp_num,
             '-L', '%s' % entry_label,