$OpenBSD$
https://code.google.com/p/nvidia-texture-tools/source/detail?r=1156
http://trac.wildfiregames.com/browser/ps/trunk/libraries/nvtt/issue176.patch
--- src/nvcore/nvcore.h.orig	Fri May 14 19:59:28 2010
+++ src/nvcore/nvcore.h	Fri Nov  2 01:24:40 2012
@@ -38,6 +38,9 @@
 #if defined POSH_OS_LINUX
 #	define NV_OS_LINUX 1
 #	define NV_OS_UNIX 1
+#elif defined POSH_OS_OPENBSD
+#	define NV_OS_OPENBSD 1
+#	define NV_OS_UNIX 1
 #elif defined POSH_OS_CYGWIN32
 #	define NV_OS_CYGWIN 1
 #elif defined POSH_OS_MINGW
@@ -99,6 +102,23 @@
 #define NV_ENDIAN_STRING	POSH_ENDIAN_STRING
 
 
+// Type definitions:
+typedef posh_u8_t   uint8;
+typedef posh_i8_t   int8;
+
+typedef posh_u16_t  uint16;
+typedef posh_i16_t  int16;
+
+typedef posh_u32_t  uint32;
+typedef posh_i32_t  int32;
+
+typedef posh_u64_t  uint64;
+typedef posh_i64_t  int64;
+
+// Aliases
+typedef uint32      uint;
+
+
 // Version string:
 #define NV_VERSION_STRING \
 	NV_OS_STRING "/" NV_CC_STRING "/" NV_CPU_STRING"/" \
@@ -158,7 +178,7 @@
 #elif NV_CC_GNUC
 #	if NV_OS_LINUX
 #		include "DefsGnucLinux.h"
-#	elif NV_OS_DARWIN
+#	elif NV_OS_DARWIN || NV_OS_OPENBSD
 #		include "DefsGnucDarwin.h"
 #	elif NV_OS_MINGW
 #		include "DefsGnucWin32.h"