tests: Add more details to help with initial setup configuration

This documents some more steps needed during initial test setup
configuration to make it easier to get this running even without
thorough knowledge of the network setup used by the operating system.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

tests/hwsim/README

@@ -51,10 +51,21 @@ make
 cd ../mac80211_hwsim/tools
 make
 
+Alternatively, the build.sh script here can be used to run these steps
+with conditional creation of .config files only if they do not exist.
+
 The test scripts can find the binaries in the locations where they were
 built. It is also possible to install hwsim_test and wlantest_cli
 somewhat on the path to use pre-built tools.
 
+Please note that some of the configuration parameters used to enable
+more testing coverage may require development packages that may not be
+installed by default in many distributions. For example, following
+Debian/Ubuntu packages are likely to be needed:
+- binutils-dev
+- libsqlite3-dev
+- libpcap-dev
+
 
 wpaspy
 ------
@@ -102,6 +113,16 @@ wlan0..4 gets assigned as the interface names for the mac80211_hwsim
 radios. It may also be possible to rename the interface expectations in
 run-tests.py to allow other names to be used.
 
+Please also note that some commonly enabled tools, like NetworkManager,
+may end up trying to control new network interfaces automatically. This
+can result in conflicts with the test scripts and you may need to
+disable such network services or at least mark the mac80211_hwsim wlan#
+interfaces as umanaged. As an example, this can be done in
+/etc/NetworkManager/NetworkManager.conf with following addition:
+
+[keyfile]
+unmanaged-devices=mac:02:00:00:00:00:00;mac:02:00:00:00:01:00;mac:02:00:00:00:02:00;mac:02:00:00:00:03:00;mac:02:00:00:00:04:00
+
 
 Running tests
 -------------