commands/efi/efifwsetup: Print an error if boot to firmware setup is not supported

The "fwsetup" command is only registered if the firmware supports booting
to the firmware setup UI. But it could be possible that the GRUB config
already contains a "fwsetup" entry, because it was generated in a machine
that has support for this feature.

To prevent users getting an error like:

    error: ../../grub-core/script/function.c:109:can't find command `fwsetup'.

if it is not supported by the firmware, let's just always register the
command but print a more accurate message if the firmware doesn't
support this option.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Robbie Harwood <rharwood@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/grub-core/commands/efi/efifwsetup.c b/grub-core/commands/efi/efifwsetup.c
index de986925c420cd2baa2a90355f321a8b3dd1ed28..7b6d4bc9fe4c7d3dabba2f51f1495caba50b1653 100644 (file)
--- a/grub-core/commands/efi/efifwsetup.c
+++ b/grub-core/commands/efi/efifwsetup.c
@@ -27,6 +27,8 @@
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
+static grub_efi_boolean_t efifwsetup_is_supported (void);
+
 static grub_err_t
 grub_cmd_fwsetup (grub_command_t cmd __attribute__ ((unused)),
                  int argc __attribute__ ((unused)),
@@ -38,6 +40,10 @@ grub_cmd_fwsetup (grub_command_t cmd __attribute__ ((unused)),
   grub_size_t oi_size;
   static grub_efi_guid_t global = GRUB_EFI_GLOBAL_VARIABLE_GUID;
 
+  if (!efifwsetup_is_supported ())
+         return grub_error (GRUB_ERR_INVALID_COMMAND,
+                            N_("reboot to firmware setup is not supported by the current firmware"));
+
   grub_efi_get_variable ("OsIndications", &global, &oi_size,
                         (void **) &old_os_indications);
 
@@ -82,10 +88,8 @@ efifwsetup_is_supported (void)
 
 GRUB_MOD_INIT (efifwsetup)
 {
-  if (efifwsetup_is_supported ())
-    cmd = grub_register_command ("fwsetup", grub_cmd_fwsetup, NULL,
-                                N_("Reboot into firmware setup menu."));
-
+  cmd = grub_register_command ("fwsetup", grub_cmd_fwsetup, NULL,
+                               N_("Reboot into firmware setup menu."));
 }
 
 GRUB_MOD_FINI (efifwsetup)