README: Add GnuTLS seciont on GNUTLS_NO_EXPLICIT_INIT

Warn users of GnuTLS about the behavior of gnutls_global_init() which
might block the loading of ConnMan.

1 files changed, 16 insertions, 0 deletions

diff --git a/README b/README
index f4d18951..1e066ce7 100644
--- a/README
+++ b/README
@@ -355,6 +355,22 @@ network. While the same setup works well for a WiFi or ethernet
 uplink.
 
 
+GnuTLS
+======
+
+When using GnuTLS be aware that depending on the configuration of
+GnuTLS does either an lazy or eager initialization of an internal
+entropy pool using /dev/urandom. On eager initialization the loading
+of ConnMan will be delayed by the link loader until the entropy pool
+is filled. On smaller system this can easily delay the startup of
+ConnMan by several seconds (we had reports of 25 seconds and more
+delay).
+
+GnuTLS allows to switch back to lazy evaluation when the environment
+variable GNUTLS_NO_EXPLICIT_INIT. For more details please read
+the man page to gnutls_global_init(3).
+
+
 Online check
 ============