Add yotta test builds to all.sh
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 14abd2d..8b171ba 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -41,7 +41,7 @@
 {
     make clean
 
-    find . -iname '*cmake*' -not -name CMakeLists.txt -exec rm -rf {} \+
+    find . -name yotta -prune -o -iname '*cmake*' -not -name CMakeLists.txt -exec rm -rf {} \+
     rm -f include/Makefile include/mbedtls/Makefile programs/*/Makefile
     git update-index --no-skip-worktree Makefile library/Makefile programs/Makefile tests/Makefile
     git checkout -- Makefile library/Makefile programs/Makefile tests/Makefile
@@ -83,6 +83,10 @@
 cleanup
 tests/scripts/check-names.sh
 
+msg "build: create and build yotta module" # ~ 30s
+cleanup
+tests/scripts/yotta-build.sh
+
 msg "build: cmake, gcc, ASan" # ~ 1 min 50s
 cleanup
 CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
diff --git a/tests/scripts/yotta-build.sh b/tests/scripts/yotta-build.sh
new file mode 100755
index 0000000..59cedf4
--- /dev/null
+++ b/tests/scripts/yotta-build.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+
+# Do test builds of the yotta module for all supported targets
+
+set -eu
+
+yotta/create-module.sh
+cd yotta/module
+# yt update # needs network
+
+yotta_build()
+{
+    TARGET=$1
+    echo; echo "*** $TARGET ***"
+    yt target $TARGET
+    yt build
+}
+
+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