+#ifdef __riscv_f
+
+#define kernel_fpu_begin() \
+	static_assert(false, "floating-point code must use a separate translation unit")
+#define kernel_fpu_end() kernel_fpu_begin()
+
+#else
+
+void kernel_fpu_begin(void);
+void kernel_fpu_end(void);
+
+#endif

I'll assume this is related to trick that places code in a separate
translation unit, but I fail to understand it.  Can you add a comment
explaining it?