diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index afbcaff..ee0df0c 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -181,6 +181,12 @@
 echo "GNUTLS_LEGACY_CLI: $GNUTLS_LEGACY_CLI"
 echo "GNUTLS_LEGACY_SERV: $GNUTLS_LEGACY_SERV"
 
+# To avoid setting OpenSSL and GnuTLS for each call to compat.sh and ssl-opt.sh
+# we just export the variables they require
+export OPENSSL_CMD="$OPENSSL"
+export GNUTLS_CLI="$GNUTLS_CLI"
+export GNUTLS_SERV="$GNUTLS_SERV"
+
 # Make sure the tools we need are available.
 check_tools "$OPENSSL" "$OPENSSL_LEGACY" "$GNUTLS_CLI" "$GNUTLS_SERV" \
     "$GNUTLS_LEGACY_CLI" "$GNUTLS_LEGACY_SERV" "doxygen" "dot" \
diff --git a/tests/scripts/basic-build-test.sh b/tests/scripts/basic-build-test.sh
index e8b6164..b405871 100755
--- a/tests/scripts/basic-build-test.sh
+++ b/tests/scripts/basic-build-test.sh
@@ -36,11 +36,30 @@
     exit 1
 fi
 
+: ${OPENSSL:="openssl"}
+: ${OPENSSL_LEGACY:="$OPENSSL"}
+: ${GNUTLS_CLI:="gnutls-cli"}
+: ${GNUTLS_SERV:="gnutls-serv"}
+: ${GNUTLS_LEGACY_CLI:="$GNUTLS_CLI"}
+: ${GNUTLS_LEGACY_SERV:="$GNUTLS_SERV"}
+
+# To avoid setting OpenSSL and GnuTLS for each call to compat.sh and ssl-opt.sh
+# we just export the variables they require
+export OPENSSL_CMD="$OPENSSL"
+export GNUTLS_CLI="$GNUTLS_CLI"
+export GNUTLS_SERV="$GNUTLS_SERV"
+
 CONFIG_H='include/mbedtls/config.h'
 CONFIG_BAK="$CONFIG_H.bak"
 
 # Step 0 - print build environment info
-scripts/output_env.sh
+OPENSSL="$OPENSSL"                           \
+    OPENSSL_LEGACY="$OPENSSL_LEGACY"         \
+    GNUTLS_CLI="$GNUTLS_CLI"                 \
+    GNUTLS_SERV="$GNUTLS_SERV"               \
+    GNUTLS_LEGACY_CLI="$GNUTLS_LEGACY_CLI"   \
+    GNUTLS_LEGACY_SERV="$GNUTLS_LEGACY_SERV" \
+    scripts/output_env.sh
 echo
 
 # Step 1 - Make and instrumented build for code coverage
@@ -65,7 +84,15 @@
 echo
 
 # Step 2c - Compatibility tests
-sh compat.sh |tee compat-test-$TEST_OUTPUT
+sh compat.sh -m 'tls1 tls1_1 tls1_2 dtls1 dtls1_2' | \
+    tee compat-test-$TEST_OUTPUT
+OPENSSL_CMD="$OPENSSL_LEGACY"                               \
+    sh compat.sh -m 'ssl3' |tee -a compat-test-$TEST_OUTPUT
+OPENSSL_CMD="$OPENSSL_LEGACY"                                       \
+    GNUTLS_CLI="$GNUTLS_LEGACY_CLI"                                 \
+    GNUTLS_SERV="$GNUTLS_LEGACY_SERV"                               \
+    sh compat.sh -e '3DES\|DES-CBC3' -f 'NULL\|DES\|RC4\|ARCFOUR' | \
+    tee -a compat-test-$TEST_OUTPUT
 echo
 
 # Step 3 - Process the coverage report
@@ -128,9 +155,9 @@
 # Step 4c - System Compatibility tests
 echo "System/Compatibility tests - tests/compat.sh"
 
-PASSED_TESTS=$(tail -n5 compat-test-$TEST_OUTPUT|sed -n -e 's/.* (\([0-9]*\) \/ [0-9]* tests ([0-9]* skipped))$/\1/p')
-SKIPPED_TESTS=$(tail -n5 compat-test-$TEST_OUTPUT|sed -n -e 's/.* ([0-9]* \/ [0-9]* tests (\([0-9]*\) skipped))$/\1/p')
-EXED_TESTS=$(tail -n5 compat-test-$TEST_OUTPUT|sed -n -e 's/.* ([0-9]* \/ \([0-9]*\) tests ([0-9]* skipped))$/\1/p')
+PASSED_TESTS=$(cat compat-test-$TEST_OUTPUT | sed -n -e 's/.* (\([0-9]*\) \/ [0-9]* tests ([0-9]* skipped))$/\1/p' | awk 'BEGIN{ s = 0 } { s += $1 } END{ print s }')
+SKIPPED_TESTS=$(cat compat-test-$TEST_OUTPUT | sed -n -e 's/.* ([0-9]* \/ [0-9]* tests (\([0-9]*\) skipped))$/\1/p' | awk 'BEGIN{ s = 0 } { s += $1 } END{ print s }')
+EXED_TESTS=$(cat compat-test-$TEST_OUTPUT | sed -n -e 's/.* ([0-9]* \/ \([0-9]*\) tests ([0-9]* skipped))$/\1/p' | awk 'BEGIN{ s = 0 } { s += $1 } END{ print s }')
 FAILED_TESTS=$(($EXED_TESTS - $PASSED_TESTS))
 
 echo "Passed             : $PASSED_TESTS"
diff --git a/tests/scripts/yotta-build.sh b/tests/scripts/yotta-build.sh
index 19cc576..4bae34a 100755
--- a/tests/scripts/yotta-build.sh
+++ b/tests/scripts/yotta-build.sh
@@ -1,12 +1,26 @@
 #!/bin/sh
 
-# Do test builds of the yotta module for all supported targets
+# yotta-build.sh
+#
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
+# Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
+#
+# Purpose
+#
+# To run test builds of the yotta module for all supported targets.
 
 set -eu
 
-yotta/create-module.sh
-cd yotta/module
-yt update || true # needs network
+check_tools()
+{
+    for TOOL in "$@"; do
+        if ! `hash "$TOOL" >/dev/null 2>&1`; then
+            echo "$TOOL not found!" >&2
+            exit 1
+        fi
+    done
+}
 
 yotta_build()
 {
@@ -19,22 +33,29 @@
     yt -t $TARGET build -d
 }
 
+# Make sure the tools we need are available.
+check_tools "arm-none-eabi-gcc" "armcc" "yotta"
+
+yotta/create-module.sh
+cd yotta/module
+yt update || true # needs network
+
 if uname -a | grep 'Linux.*x86' >/dev/null; then
     yotta_build x86-linux-native
 fi
 if uname -a | grep 'Darwin.*x86' >/dev/null; then
     yotta_build x86-osx-native
 fi
-if which armcc >/dev/null && armcc --help >/dev/null 2>&1; then
-    yotta_build frdm-k64f-armcc
-    #yotta_build nordic-nrf51822-16k-armcc
-fi
-if which arm-none-eabi-gcc >/dev/null; then
-    yotta_build frdm-k64f-gcc
-    #yotta_build st-nucleo-f401re-gcc # dirent
-    #yotta_build stm32f429i-disco-gcc # fails in mbed-hal-st-stm32f4
-    #yotta_build nordic-nrf51822-16k-gcc # fails in minar-platform
-    #yotta_build bbc-microbit-classic-gcc # fails in minar-platform
-    #yotta_build st-stm32f439zi-gcc # fails in mbed-hal-st-stm32f4
-    #yotta_build st-stm32f429i-disco-gcc # fails in mbed-hal-st-stm32f4
-fi
+
+# armcc build tests.
+yotta_build frdm-k64f-armcc
+#yotta_build nordic-nrf51822-16k-armcc
+
+# arm-none-eabi-gcc build tests.
+yotta_build frdm-k64f-gcc
+#yotta_build st-nucleo-f401re-gcc # dirent
+#yotta_build stm32f429i-disco-gcc # fails in mbed-hal-st-stm32f4
+#yotta_build nordic-nrf51822-16k-gcc # fails in minar-platform
+#yotta_build bbc-microbit-classic-gcc # fails in minar-platform
+#yotta_build st-stm32f439zi-gcc # fails in mbed-hal-st-stm32f4
+#yotta_build st-stm32f429i-disco-gcc # fails in mbed-hal-st-stm32f4