show the most important compiled-in features on startup screen

c64/kernal/assets/kernal_messages.s

@@ -25,6 +25,9 @@
 .label __MSG_KERNAL_PANIC_ROM_MISMATCH = __msg_kernalpanic_rom_mismatch - __msg_kernal_first
 #endif
 
+#if CONFIG_SHOW_FEATURES
+.label __MSG_KERNAL_FEATURES           = __msg_kernalfeatures           - __msg_kernal_first
+#endif
 
 __msg_kernal_first:
 
@@ -59,12 +62,14 @@ __msg_kernalto_hex:
 #if CONFIG_SHOW_PAL_NTSC
 
 __msg_kernalpal:
-	.text "PAL,"
-	.byte $80 + $20 // end of string mark + space
+	.text "PAL"
+	.byte $0D
+	.byte $80 + $0D // end of string mark + return
 
 __msg_kernalntsc:
-	.text "NTSC,"
-	.byte $80 + $20 // end of string mark + space
+	.text "NTSC"
+	.byte $0D
+	.byte $80 + $0D // end of string mark + return
 
 #endif // CONFIG_SHOW_PAL_NTSC
 
@@ -79,3 +84,11 @@ __msg_kernalpanic_rom_mismatch:
 	.byte $80 + $48 // end of string mark + 'H'
 
 #endif // CONFIG_PANIC_SCREEN
+
+#if CONFIG_SHOW_FEATURES
+
+__msg_kernalfeatures:
+	.text BUILD_FEATURES_STR()
+	.byte $80 + $0D // end of string mark + return
+
+#endif // CONFIG_SHOW_FEATURES