$NetBSD: patch-ab,v 1.4 2015/03/31 15:50:36 joerg Exp $

--- config.h.orig	Thu Mar 23 10:38:56 1995
+++ config.h
@@ -108,6 +108,32 @@
 #   define USE_TESTS
 #endif
 
+#ifdef __NetBSD__
+#   define OPSYS "NetBSD"
+#   define USE_UNISTD
+#   define USE_CBREAK
+#   define USE_MMAP
+#   define USE_SIGNALS
+#   define USE_WAIT
+#   define UNIX
+#   define USE_ALLOCA
+#   define USE_READLINE
+#   define USE_MEMTEST
+#   define USE_TESTS
+#   define USE_SIGNAL_H
+#if defined(__x86_64__)
+#   define IN_OUT_INSTRUCTIONS
+#   define my_ioperm(x,y,z) x86_64_iopl(1)
+#elif defined(__i386__)
+#   define IN_OUT_INSTRUCTIONS
+#   define my_ioperm(x,y,z) i386_iopl(1)
+#else
+#   define my_ioperm(x,y,z) 0
+#endif
+
+#define SIGNAL_FUNCTION_CAST (void (*)())
+#endif
+
 /*
  * Here starts the section that provides defaults for most systems, that
  * can be overridden for a specific OS/compiler.