From 427fea0ba6e4c9fd5a5a5f8e41dfd0916006abc8 Mon Sep 17 00:00:00 2001
From: Bill Paul <wpaul@FreeBSD.org>
Date: Sun, 17 Apr 2005 19:36:08 +0000
Subject: [PATCH] Now that the GDT has been reorganized and GNDIS_SEL has been
 reserved for us, use it if it's available, otherwise default to using slot 7
 as before.

---
 sys/compat/ndis/kern_windrv.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/sys/compat/ndis/kern_windrv.c b/sys/compat/ndis/kern_windrv.c
index 81b3a6dbe779..cd631fd36a58 100644
--- a/sys/compat/ndis/kern_windrv.c
+++ b/sys/compat/ndis/kern_windrv.c
@@ -52,6 +52,10 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/queue.h>
 
+#ifdef __i386__
+#include <machine/segments.h>
+#endif
+
 #include <compat/ndis/pe_var.h>
 #include <compat/ndis/cfg_var.h>
 #include <compat/ndis/resource_var.h>
@@ -545,7 +549,19 @@ extern void x86_setldt(struct gdt *, uint16_t);
 
 #define SEL_LDT	4		/* local descriptor table */
 #define SEL_TO_FS(x)		(((x) << 3))
-#define FREEBSD_EMPTYSEL	7
+
+/*
+ * FreeBSD 6.0 and later has a special GDT segment reserved
+ * specifically for us, so if GNDIS_SEL is defined, use that.
+ * If not, use GTGATE_SEL, which is uninitialized and infrequently
+ * used.
+ */
+
+#ifdef GNDIS_SEL
+#define FREEBSD_EMPTYSEL	GNDIS_SEL
+#else
+#define FREEBSD_EMPTYSEL	GTGATE_SEL	/* slot 7 */
+#endif
 
 /*
  * The meanings of various bits in a descriptor vary a little