Document uio/vfio configure options as --without-* since they are enabled by default when available

README

@@ -160,6 +160,10 @@ BFGMiner specific configuration options:
 	--with-system-libblkmaker  Use system libblkmaker rather than bundled one
 	                           (default disabled)
 	--with-udevrulesdir=DIR Install udev rules into this directory
+	--without-uio           Compile support for PCI devices via Linux UIO
+	                        interface (default enabled)
+	--without-vfio          Compile support for PCI devices via Linux VFIO
+	                        interface (default enabled)
 	--without-sensors       Build with libsensors monitoring (default enabled)
 	--without-curses        Compile support for curses TUI (default enabled)
 	--without-libmicrohttpd Compile support for libmicrohttpd getwork server

configure.ac

@@ -224,11 +224,11 @@ AC_CHECK_DECL([HASH_ITER],[
 lowl_pci=no
 if test "x$ac_cv_header_sys_mman_h" = "xyes"; then
 	AC_ARG_WITH([uio],
-		[AC_HELP_STRING([--with-uio],[Compile support for PCI devices via Linux UIO interface (default enabled)])],
+		[AC_HELP_STRING([--without-uio],[Compile support for PCI devices via Linux UIO interface (default enabled)])],
 		[uio=$withval],
 		[uio=yes])
 	AC_ARG_WITH([vfio],
-		[AC_HELP_STRING([--with-vfio],[Compile support for PCI devices via Linux VFIO interface (default enabled)])],
+		[AC_HELP_STRING([--without-vfio],[Compile support for PCI devices via Linux VFIO interface (default enabled)])],
 		[vfio=$enableval],
 		[vfio=auto])
 	if test "x$vfio" != "xno"; then