Merge pull request #3038 from srcshelton/note-bootloader-settings

Note which settings pertain only to the bootloader...

documentation/asciidoc/computers/config_txt/what_is_config_txt.adoc

@@ -44,7 +44,21 @@ Causes the content of the specified file to be inserted into the current file.
 
 For example, adding the line `include extraconfig.txt` to `config.txt` will include the content of `extraconfig.txt` file in the `config.txt` file.
 
-*Include directives are not supported by bootcode.bin or the EEPROM bootloader*
+[NOTE]
+====
+
+*Include directives are not supported by the bootcode.bin or EEPROM bootloaders*.
+
+Settings which are handled by the bootloader and so which will only take effect if they are specified in `config.txt` (rather than any additional included file) are:
+
+* `bootcode_delay`,
+* `gpu_mem`, `gpu_mem_256`, `gpu_mem_512`, `gpu_mem_1024`,
+* `total_mem`,
+* `sdram_freq`,
+* `start_x`, `start_debug`, `start_file`, `fixup_file`,
+* `uart_2ndstage`.
+
+====
 
 ==== Conditional Filtering