adapted suggestions

src/lib/bootloader/bootloader_factory.rb

@@ -54,7 +54,9 @@ def supported_names
         if Yast::Mode.config
           # default means bootloader use what it think is the best
           result = BootloaderFactory::SUPPORTED_BOOTLOADERS.clone
-          result << SYSTEMDBOOT if Yast::ProductFeatures.GetBooleanFeature("globals", "enable_systemd_boot")
+          if Yast::ProductFeatures.GetBooleanFeature("globals", "enable_systemd_boot") &&
+             Yast::Arch.x86_64 # only x86_64 is supported
+            result << SYSTEMDBOOT
           result << DEFAULT_KEYWORD
           return result
         end

src/lib/bootloader/systemdboot.rb

@@ -30,7 +30,6 @@ def initialize
       super
 
       textdomain "bootloader"
-      self.menue_timeout = Yast::ProductFeatures.GetIntegerFeature("globals", "boot_timeout").to_i
     end
 
     def merge(other)
@@ -41,14 +40,6 @@ def merge(other)
       self.secure_boot = other.secure_boot unless other.secure_boot.nil?
     end
 
-    def cpu_mitigations
-      Bootloader::CpuMitigations.new(:manual)
-    end
-
-    def cpu_mitigations=(value)
-      log.info "ignoring set of cpu_mitigations (#{value}) in systemd bootloader."
-    end
-
     def read
       super
 
@@ -72,6 +63,8 @@ def write(etc_only: false)
     def propose
       super
       log.info("Propose settings...")
+      self.menue_timeout = Yast::ProductFeatures.GetIntegerFeature("globals", "boot_timeout").to_i
+      self.secure_boot = Systeminfo.secure_boot_supported?
     end
 
     def status_string(status)
@@ -116,7 +109,7 @@ def packages
       res = super
 
       case Yast::Arch.architecture
-      when "x86_64", "aarch64"
+      when "x86_64"
         res << "shim" << "mokutil" if secure_boot
       else
         log.warn "Unknown architecture #{Yast::Arch.architecture} for EFI"