diff --git a/litex/soc/cores/cpu/__init__.py b/litex/soc/cores/cpu/__init__.py
index 73ceed968..70ff1c22f 100644
--- a/litex/soc/cores/cpu/__init__.py
+++ b/litex/soc/cores/cpu/__init__.py
@@ -34,7 +34,7 @@ class CPUNone(CPU):
     io_regions           = {0x00000000: 0x100000000} # origin, length
     periph_buses         = []
     memory_buses         = []
-    mem_map              = {"csr": 0x00000000}
+    mem_map              = {"csr": 0x00000000, "ethmac": 0x00020000} # FIXME: remove ethmac.
 
 CPU_GCC_TRIPLE_RISCV32 = (
     "riscv64-unknown-elf",