dasharo.ipxe: fail message within script

Make iPXE itself print out an error if either of the network boot
options fail, instead of quietly returning to the menu or passing the
error for EDK2 to handle.

Signed-off-by: Filip Lewiński <filip.lewinski@3mdeb.com>

dasharo/dasharo.ipxe

@@ -15,23 +15,43 @@ choose --default boot --timeout 3000 target && goto ${target}
 
 # main menu options
 :boot
-autoboot
+autoboot || goto autoboot_failed
 goto MENU
 
 :dasharo
-dhcp ||
-chain https://boot.dasharo.com/dts/dts.ipxe ||
-exit 1
+dhcp || goto dhcp_failed
+chain https://boot.dasharo.com/dts/dts.ipxe || goto dts_failed
+goto MENU
 
 :netbootxyz
-dhcp ||
-chain https://boot.netboot.xyz/menu.ipxe ||
-exit 1
+dhcp || goto dhcp_failed
+chain https://boot.netboot.xyz/menu.ipxe || goto netbootxyz_failed
+goto MENU
 
 :shell
 echo You are now in iPXE shell. Type "exit" to go back to the main menu.
 shell ||
 goto MENU
 
+:autoboot_failed
+echo Autoboot failed.
+prompt Press any key to return to menu...
+goto MENU
+
+:dhcp_failed
+echo DHCP command failed.
+prompt Press any key to return to menu...
+goto MENU
+
+:dts_failed
+echo Loading DTS failed.
+prompt Press any key to return to menu...
+goto MENU
+
+:netbootxyz_failed
+echo Loading netboot.xyz failed.
+prompt Press any key to return to menu...
+goto MENU
+
 autoboot