Index: src/platform.h
==================================================================
--- src/platform.h
+++ src/platform.h
@@ -87,10 +87,15 @@
 # if defined(__mc68020__) || defined(OF_M68030)
 #  define OF_M68020
 # endif
 # if defined(__mc68010__) || defined(OF_M68020)
 #  define OF_M68010
+# endif
+# if defined(__riscv) && defined(__riscv_xlen) && __riscv_xlen == 64
+#  define OF_RISCV64
+# elif defined(__riscv)
+#  define OF_RISCV
 # endif
 #endif
 
 #if defined(__APPLE__)
 # include <TargetConditionals.h>