X11 stuff doesn't build correctly on Cygwin

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1474 42af7a65-404d-4744-a932-0658087f49c3

arch/sim/src/Makefile

@@ -45,7 +45,10 @@ CSRCS		= up_initialize.c up_idle.c up_interruptcontext.c \
 		  up_releasepending.c up_reprioritizertr.c \
 		  up_exit.c up_schedulesigaction.c up_allocateheap.c \
 		  up_devconsole.c up_framebuffer.c
-HOSTSRCS	= up_stdio.c up_hostusleep.c up_x11framebuffer.c
+HOSTSRCS	= up_stdio.c up_hostusleep.c
+ifneq ($(HOSTOS),Cygwin) 
+  HOSTSRCS	+=  up_x11framebuffer.c
+endif
 ifeq ($(CONFIG_FS_FAT),y)
 CSRCS		+= up_blockdevice.c up_deviceimage.c
 endif
@@ -63,7 +66,11 @@ SRCS		= $(ASRCS) $(CSRCS) $(HOSTSRCS)
 OBJS		= $(AOBJS) $(COBJS) $(HOSTOBJS)
 
 LDFLAGS		= $(ARCHSCRIPT)
-STDLIBS		= -lX11 -lXext -lc
+ifneq ($(HOSTOS),Cygwin)
+  STDLIBS	= -lX11 -lXext -lc
+else
+  STDLIBS       = -lc
+endif
 ifeq ($(CONFIG_FS_FAT),y)
 STDLIBS		+= -lz
 endif