+ /*
+ * Opening poke device on systems with the linked change below
+ * automatically changes process IOPL to 3 and closing its file
+ * descriptor changes process IOPL back to 0, which give access
+ * to all x86 IO ports via x86 in/out instructions for this
+ * userspace process. To support also older systems without this
+ * change, access IO ports via ioctl() instead of x86 in/out.
+ * https://review.haiku-os.org/c/haiku/+/1077
+ */