unix: Allow to override MICROPY_GCREGS_SETJMP from cmdline.
diff --git a/unix/mpconfigport.h b/unix/mpconfigport.h
index 3426ae4..1559bdb 100644
--- a/unix/mpconfigport.h
+++ b/unix/mpconfigport.h
@@ -53,7 +53,9 @@
#define MICROPY_ERROR_REPORTING (MICROPY_ERROR_REPORTING_DETAILED)
// Define to 1 to use untested inefficient GC helper implementation
// (if more efficient arch-specific one is not available).
+#ifndef MICROPY_GCREGS_SETJMP
#define MICROPY_GCREGS_SETJMP (0)
+#endif
extern const struct _mp_obj_module_t mp_module_os;
extern const struct _mp_obj_module_t mp_module_time;