pass nolutram for 4k

litex_boards/platforms/sipeed_tang_nano_4k.py

@@ -92,10 +92,13 @@ def __init__(self, toolchain="gowin"):
         # Licensed GoWin IDE v. 1.9.7.06 Beta
         # GowinPlatform.__init__(self, "GW1NSR-LV4CQN48PC7/I6", _io, _connectors, toolchain=toolchain, devicename="GW1NSR-4C")
 
-        # this is just a software check that doesn't translate to hardware
-        # apicula does not implement this check, so beware of bricking your board
         if toolchain=="gowin":
+            # this is just a software check that doesn't translate to hardware
+            # apicula does not implement this check, so beware of bricking your board
             self.toolchain.options["use_mode_as_gpio"] = 1
+        else:
+            # yosys doesn't know that 4K doesn't have lutram so we tell it
+            self.toolchain._synth_opts += " -nolutram"
 
         self.toolchain.options["use_mspi_as_gpio"] = 1
         self.toolchain.options["use_done_as_gpio"] = 1