diff --git a/cores/esp8266/umm_malloc/umm_malloc.cpp b/cores/esp8266/umm_malloc/umm_malloc.cpp
index 8314c5ec60..09cfbdda71 100644
--- a/cores/esp8266/umm_malloc/umm_malloc.cpp
+++ b/cores/esp8266/umm_malloc/umm_malloc.cpp
@@ -520,7 +520,7 @@ extern int umm_last_fail_alloc_size;
 #endif
 
 // Macro to place constant strings into PROGMEM and print them properly
-#define printf(fmt, ...)  do { static const char fstr[] PROGMEM = fmt; char rstr[sizeof(fmt)]; for (size_t i=0; i<sizeof(rstr); i++) rstr[i] = fstr[i]; printf(rstr, ##__VA_ARGS__); } while (0)
+#define printf(fmt, ...) printf(PSTR(fmt), ## __VA_ARGS__ )
 
 /* -- dbglog {{{ */
 
diff --git a/tests/device/Makefile b/tests/device/Makefile
index f0efa23d13..3412bc96dc 100644
--- a/tests/device/Makefile
+++ b/tests/device/Makefile
@@ -23,6 +23,7 @@ TEST_REPORT_HTML := test_report.html
 
 ifneq ("$(V)","1")
 	SILENT = @
+	REDIR = >& /dev/null
 else
 	BUILDER_DEBUG_FLAG = -verbose
 	RUNNER_DEBUG_FLAG = -d
@@ -50,10 +51,11 @@ $(TEST_LIST):
 ifneq ("$(NO_BUILD)","1")
 	@test -n "$(ARDUINO_IDE_PATH)" || (echo "Please export ARDUINO_IDE_PATH" && exit 1)
 	@echo Compiling $(notdir $@)
+	@rm -f $(LOCAL_BUILD_DIR)/build.options.json
 	$(SILENT)$(BUILD_TOOL) -compile -logger=human \
 		-libraries "$(PWD)/libraries" \
 		-core-api-version="10608" \
-		-warnings=none \
+		-warnings=all \
 		$(BUILDER_DEBUG_FLAG) \
 		-build-path $(LOCAL_BUILD_DIR) \
 		-tools $(ARDUINO_IDE_PATH)/tools-builder \
@@ -64,16 +66,17 @@ ifneq ("$(NO_BUILD)","1")
 endif
 ifneq ("$(NO_UPLOAD)","1")
 	@test -n "$(UPLOAD_PORT)" || (echo "Failed to detect upload port, please export UPLOAD_PORT manually" && exit 1)
-	@test -e $(dir $@)/make_spiffs.py && (echo "Generating and uploading SPIFFS" && \
-		(cd $(dir $@) && $(PYTHON) ./make_spiffs.py) && \
+	@test -e $(dir $@)/make_spiffs.py && ( \
+		echo "Generating and uploading SPIFFS" && \
+		(cd $(dir $@) && $(PYTHON) ./make_spiffs.py $(REDIR) ) && \
 		$(MKSPIFFS) --create $(dir $@)data/ --size 0xFB000 \
-			--block 8192 --page 256 $(LOCAL_BUILD_DIR)/spiffs.img && \
+			--block 8192 --page 256 $(LOCAL_BUILD_DIR)/spiffs.img $(REDIR) && \
 		$(ESPTOOL) $(UPLOAD_VERBOSE_FLAG) \
 			--chip esp8266 \
 			--port $(UPLOAD_PORT) \
 			--baud $(UPLOAD_BAUD) \
 			--after no_reset \
-			write_flash 0x300000 $(LOCAL_BUILD_DIR)/spiffs.img ) \
+			write_flash 0x300000 $(LOCAL_BUILD_DIR)/spiffs.img $(REDIR) ) \
 			|| (echo "No SPIFFS to upload")
 	@echo Uploading binary
 	$(SILENT)$(ESPTOOL) $(UPLOAD_VERBOSE_FLAG)  \
@@ -81,7 +84,7 @@ ifneq ("$(NO_UPLOAD)","1")
 		--port $(UPLOAD_PORT) \
 		--baud $(UPLOAD_BAUD) \
 		--after no_reset \
-		write_flash 0x0 $(LOCAL_BUILD_DIR)/$(notdir $@).bin # no reset
+		write_flash 0x0 $(LOCAL_BUILD_DIR)/$(notdir $@).bin $(REDIR) # no reset
 endif
 ifneq ("$(NO_RUN)","1")
 	@test -n "$(UPLOAD_PORT)" || (echo "Failed to detect upload port, please export UPLOAD_PORT manually" && exit 1)
@@ -90,7 +93,7 @@ ifneq ("$(NO_RUN)","1")
 		--chip esp8266 \
 		--port $(UPLOAD_PORT) \
 		--baud $(UPLOAD_BAUD) \
-		read_flash_status # reset
+		read_flash_status $(REDIR) # reset
 	$(SILENT)source $(BS_DIR)/virtualenv/bin/activate && \
 		$(PYTHON) $(BS_DIR)/runner.py \
 			$(RUNNER_DEBUG_FLAG) \
diff --git a/tests/device/libraries/BSTest/runner.py b/tests/device/libraries/BSTest/runner.py
index 5cf10f478b..9778f35ada 100644
--- a/tests/device/libraries/BSTest/runner.py
+++ b/tests/device/libraries/BSTest/runner.py
@@ -104,6 +104,10 @@ def run_tests(self):
                     if res != BSTestRunner.SUCCESS:
                         print('failed to set environment variables')
                         break;
+                    res = self.pretest()
+                    if res != BSTestRunner.SUCCESS:
+                        print('failed to run pretest init')
+                        break;
                     should_update_env = False
                 if name in self.mocks:
                     debug_print('setting up mocks')
@@ -198,6 +202,21 @@ def update_env(self, env_to_set):
                 return BSTestRunner.TIMEOUT
         return BSTestRunner.SUCCESS
 
+    def pretest(self):
+        # Environment now set up, call the pretest init (wifi connect, etc.)
+        self.sp.sendline('pretest');
+        timeout = 10
+        while timeout > 0:
+            res = self.sp.expect(['>>>>>bs_test_pretest result=1', EOF, TIMEOUT]) # Only expect a pass, abort testing if failure
+            if res == 0:
+                break
+            time.sleep(0.1)
+            timeout -= 0.1
+        if res != 0:
+            return BSTestRunner.TIMEOUT
+        else:
+            return BSTestRunner.SUCCESS
+
     def request_env(self, key):
         self.sp.sendline('getenv "{}"'.format(key))
         timeout = 10
diff --git a/tests/device/libraries/BSTest/src/BSArgs.h b/tests/device/libraries/BSTest/src/BSArgs.h
index e4a7008f15..060bcdf18c 100644
--- a/tests/device/libraries/BSTest/src/BSArgs.h
+++ b/tests/device/libraries/BSTest/src/BSArgs.h
@@ -69,7 +69,7 @@ inline size_t split_args(char *line, char **argv, size_t argv_size)
     const int ESCAPE = '\\';
     const int SPACE = ' ';
     split_state_t state = SS_SPACE;
-    int argc = 0;
+    size_t argc = 0;
     char *next_arg_start = line;
     char *out_ptr = line;
     for (char *in_ptr = line; argc < argv_size - 1; ++in_ptr) {
@@ -148,4 +148,4 @@ inline size_t split_args(char *line, char **argv, size_t argv_size)
 
 } // namespace protocol
 
-#endif //BS_ARGS_H
\ No newline at end of file
+#endif //BS_ARGS_H
diff --git a/tests/device/libraries/BSTest/src/BSProtocol.h b/tests/device/libraries/BSTest/src/BSProtocol.h
index f4ed73bd7a..05a874f956 100644
--- a/tests/device/libraries/BSTest/src/BSProtocol.h
+++ b/tests/device/libraries/BSTest/src/BSProtocol.h
@@ -5,6 +5,8 @@
 
 #define BS_LINE_PREFIX ">>>>>bs_test_"
 
+extern bool pretest();
+
 namespace bs
 {
 namespace protocol
@@ -58,6 +60,12 @@ void output_getenv_result(IO& io, const char* key, const char* value)
     io.printf(BS_LINE_PREFIX "getenv value=\"%s\"\n", value);
 }
 
+template<typename IO>
+void output_pretest_result(IO& io, bool res)
+{
+    io.printf(BS_LINE_PREFIX "pretest result=%d\n", res?1:0);
+}
+
 template<typename IO>
 bool input_handle(IO& io, char* line_buf, size_t line_buf_size, int& test_num)
 {
@@ -87,6 +95,14 @@ bool input_handle(IO& io, char* line_buf, size_t line_buf_size, int& test_num)
         output_getenv_result(io, argv[1], (value != NULL) ? value : "");
         return false;
     }
+    if (strcmp(argv[0], "pretest") == 0) {
+        if (argc != 1) {
+            return false;
+        }
+        bool res = ::pretest();
+        output_pretest_result(io, res);
+        return false;
+    }
     /* not one of the commands, try to parse as test number */
     char* endptr;
     test_num = (int) strtol(argv[0], &endptr, 10);
diff --git a/tests/device/test_BearSSL/test_BearSSL.ino b/tests/device/test_BearSSL/test_BearSSL.ino
index 675c24de60..e4db2fdc0e 100644
--- a/tests/device/test_BearSSL/test_BearSSL.ino
+++ b/tests/device/test_BearSSL/test_BearSSL.ino
@@ -33,6 +33,11 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.mode(WIFI_STA);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
@@ -45,22 +50,11 @@ void setup()
     Serial.printf("Number of CA certs read: %d\n", numCerts);
     if (numCerts == 0) {
         Serial.printf("No certs found. Did you run certs-from-mozill.py and upload the SPIFFS directory before running?\n");
-        REQUIRE(1==0);
+        return false;
     }
-    BS_RUN(Serial);
-}
-
-static void stopAll()
-{
-    WiFiClient::stopAll();
-}
-
-static void disconnectWiFI()
-{
-    wifi_station_disconnect();
+    return true;
 }
 
-
 // Set time via NTP, as required for x.509 validation
 void setClock() {
   configTime(3 * 3600, 0, "pool.ntp.org", "time.nist.gov");
@@ -143,7 +137,7 @@ int run(const char *str)
     return maxUsage;
 }
 
-#define TC(x) TEST_CASE("BearSSL - Maximum stack usage < 5600 bytes @ "x".badssl.org", "[bearssl]") { REQUIRE(run(x) < 5600); }
+#define TC(x) TEST_CASE("BearSSL - Maximum stack usage < 5600 bytes @ " x ".badssl.org", "[bearssl]") { REQUIRE(run(x) < 5600); }
 
 TC("expired")
 TC("wrong.host")
diff --git a/tests/device/test_ClientContext/test_ClientContext.ino b/tests/device/test_ClientContext/test_ClientContext.ino
index 10cedf1076..25f4db2cf5 100644
--- a/tests/device/test_ClientContext/test_ClientContext.ino
+++ b/tests/device/test_ClientContext/test_ClientContext.ino
@@ -23,13 +23,18 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.mode(WIFI_STA);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
-    BS_RUN(Serial);
+    return true;
 }
 
 TEST_CASE("WiFi release ClientContext", "[clientcontext]")
diff --git a/tests/device/test_FS/test_FS.ino b/tests/device/test_FS/test_FS.ino
index b516c8b16f..0a33dc8586 100644
--- a/tests/device/test_FS/test_FS.ino
+++ b/tests/device/test_FS/test_FS.ino
@@ -10,6 +10,10 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
 
 
 TEST_CASE("read-write test","[fs]")
diff --git a/tests/device/test_Print_printf/test_Print_printf.ino b/tests/device/test_Print_printf/test_Print_printf.ino
index 7396572625..1411467f9f 100644
--- a/tests/device/test_Print_printf/test_Print_printf.ino
+++ b/tests/device/test_Print_printf/test_Print_printf.ino
@@ -9,13 +9,18 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("Print::printf works for any reasonable output length", "[Print]")
 {
 
     auto test_printf = [](size_t size) {
         StreamString str;
         auto buf = new char[size + 1];
-        for (int i = 0; i < size; ++i) {
+        for (size_t i = 0; i < size; ++i) {
             buf[i] = 'a';
         }
         buf[size] = 0;
diff --git a/tests/device/test_WiFiClient/test_WiFiClient.ino b/tests/device/test_WiFiClient/test_WiFiClient.ino
index 4d7eb73913..239d44e35d 100644
--- a/tests/device/test_WiFiClient/test_WiFiClient.ino
+++ b/tests/device/test_WiFiClient/test_WiFiClient.ino
@@ -13,13 +13,18 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.mode(WIFI_STA);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
-    BS_RUN(Serial);
+    return true;
 }
 
 static void stopAll()
@@ -53,4 +58,4 @@ TEST_CASE("WiFi disconnect during WiFiClient::connect", "[wificlient]")
 
 void loop()
 {
-}
\ No newline at end of file
+}
diff --git a/tests/device/test_WiFiServer/test_WiFiServer.ino b/tests/device/test_WiFiServer/test_WiFiServer.ino
index 2040df54c8..5af9cfce27 100644
--- a/tests/device/test_WiFiServer/test_WiFiServer.ino
+++ b/tests/device/test_WiFiServer/test_WiFiServer.ino
@@ -10,13 +10,18 @@ BS_ENV_DECLARE();
 void setup()
 {
     Serial.begin(115200);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
     MDNS.begin("esp8266-wfs-test");
-    BS_RUN(Serial);
+    return true;
 }
 
 TEST_CASE("Simple echo server", "[WiFiServer]")
diff --git a/tests/device/test_WiFi_events/test_WiFi_events.ino b/tests/device/test_WiFi_events/test_WiFi_events.ino
index 704f3c3c7d..88777b61ab 100644
--- a/tests/device/test_WiFi_events/test_WiFi_events.ino
+++ b/tests/device/test_WiFi_events/test_WiFi_events.ino
@@ -11,9 +11,14 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(false);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.mode(WIFI_OFF);
-    BS_RUN(Serial);
+    return true;
 }
 
 static std::map<WiFiEvent_t, int> sEventsReceived;
@@ -29,10 +34,13 @@ TEST_CASE("WiFi.onEvent is called for specific events", "[wifi][events]")
     sEventsReceived[WIFI_EVENT_STAMODE_DISCONNECTED] = 0;
     sEventsReceived[WIFI_EVENT_STAMODE_GOT_IP] = 0;
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
     WiFi.onEvent(onWiFiEvent, WIFI_EVENT_STAMODE_CONNECTED);
     WiFi.onEvent(onWiFiEvent, WIFI_EVENT_STAMODE_DISCONNECTED);
     WiFi.onEvent(onWiFiEvent, WIFI_EVENT_STAMODE_GOT_IP);
     WiFi.onEvent(onWiFiEvent, WIFI_EVENT_ANY);
+#pragma GCC diagnostic pop
 
     WiFi.mode(WIFI_STA);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
@@ -44,9 +52,12 @@ TEST_CASE("WiFi.onEvent is called for specific events", "[wifi][events]")
     WiFi.disconnect();
     delay(100);
     WiFi.mode(WIFI_OFF);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
     REQUIRE(sEventsReceived[WIFI_EVENT_STAMODE_CONNECTED] == 2);
     REQUIRE(sEventsReceived[WIFI_EVENT_STAMODE_DISCONNECTED] >= 2 && sEventsReceived[WIFI_EVENT_STAMODE_DISCONNECTED] % 2 == 0);
     REQUIRE(sEventsReceived[WIFI_EVENT_STAMODE_GOT_IP] == 2);
+#pragma GCC diagnostic pop
 }
 
 TEST_CASE("STA mode events are called both when using DHCP and static config", "[wifi][events]")
@@ -54,14 +65,17 @@ TEST_CASE("STA mode events are called both when using DHCP and static config", "
     String events;
     
     auto handler1 = WiFi.onStationModeConnected([&](const WiFiEventStationModeConnected& evt){
+        (void) evt;
         events += "connected,";
     });  
     auto handler2 = WiFi.onStationModeDisconnected([&](const WiFiEventStationModeDisconnected& evt){
+        (void) evt;
         if (events.length()) {
             events += "disconnected,";
         }
     });
     auto handler3 = WiFi.onStationModeGotIP([&](const WiFiEventStationModeGotIP& evt){
+        (void) evt;
         events += "got_ip,";
     });
 
@@ -104,12 +118,15 @@ TEST_CASE("Events are not called if handler is deleted", "[wifi][events]")
     String events;
     
     WiFi.onStationModeConnected([&](const WiFiEventStationModeConnected& evt){
+        (void) evt;
         events += "connected,";
     });  
     WiFi.onStationModeDisconnected([&](const WiFiEventStationModeDisconnected& evt){
+        (void) evt;
         events += "disconnected,";
     });
     WiFi.onStationModeGotIP([&](const WiFiEventStationModeGotIP& evt){
+        (void) evt;
         events += "got_ip,";
     });
 
diff --git a/tests/device/test_http_client/test_http_client.ino b/tests/device/test_http_client/test_http_client.ino
index c2c9b60e54..4757fdb4fe 100644
--- a/tests/device/test_http_client/test_http_client.ino
+++ b/tests/device/test_http_client/test_http_client.ino
@@ -11,12 +11,17 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
-    BS_RUN(Serial);
+    return true;
 }
 
 const char* fp = "44 40 9E 34 92 2D E4 61 A4 89 A8 D5 7F 71 B7 62 B3 FD DD E1";
@@ -43,7 +48,7 @@ TEST_CASE("HTTP GET & POST requests", "[HTTPClient]")
         String payload = http.getString();
         auto len = payload.length();
         REQUIRE(len == 8000);
-        for (int i = 0; i < len; ++i) {
+        for (size_t i = 0; i < len; ++i) {
             if (payload[i] != 'a') {
                 REQUIRE(false);
             }
@@ -196,7 +201,7 @@ TEST_CASE("HTTPS GET request", "[HTTPClient]")
         String payload = http.getString();
         auto len = payload.length();
         REQUIRE(len == 4000);
-        for (int i = 0; i < len; ++i) {
+        for (size_t i = 0; i < len; ++i) {
             if (payload[i] != 'a') {
                 REQUIRE(false);
             }
@@ -207,7 +212,10 @@ TEST_CASE("HTTPS GET request", "[HTTPClient]")
     //
     {
         // small request
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         axTLS::WiFiClientSecure client;
+#pragma GCC diagnostic pop
         HTTPClient http;
         http.begin(client, getenv("SERVER_IP"), 8088, "/", fp);
         auto httpCode = http.GET();
@@ -217,7 +225,10 @@ TEST_CASE("HTTPS GET request", "[HTTPClient]")
     }
     {
         // request which returns 4000 bytes
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         axTLS::WiFiClientSecure client;
+#pragma GCC diagnostic pop
         HTTPClient http;
         http.begin(client, getenv("SERVER_IP"), 8088, "/data?size=4000", fp);
         auto httpCode = http.GET();
@@ -225,7 +236,7 @@ TEST_CASE("HTTPS GET request", "[HTTPClient]")
         String payload = http.getString();
         auto len = payload.length();
         REQUIRE(len == 4000);
-        for (int i = 0; i < len; ++i) {
+        for (size_t i = 0; i < len; ++i) {
             if (payload[i] != 'a') {
                 REQUIRE(false);
             }
diff --git a/tests/device/test_http_server/test_http_server.ino b/tests/device/test_http_server/test_http_server.ino
index c408555822..e9f8bda923 100644
--- a/tests/device/test_http_server/test_http_server.ino
+++ b/tests/device/test_http_server/test_http_server.ino
@@ -16,6 +16,11 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
@@ -24,7 +29,7 @@ void setup()
     MDNS.begin("etd");
     server.onNotFound([](){ server.send(404); });
     server.begin();
-    BS_RUN(Serial);
+    return true;
 }
 
 void handle_request()
diff --git a/tests/device/test_iostream/test_iostream.ino b/tests/device/test_iostream/test_iostream.ino
index b644882bf2..db803ffe82 100644
--- a/tests/device/test_iostream/test_iostream.ino
+++ b/tests/device/test_iostream/test_iostream.ino
@@ -11,6 +11,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("can print to std::cout", "[iostream]")
 {
     std::stringstream test_stream("");
diff --git a/tests/device/test_libc/test_libc.ino b/tests/device/test_libc/test_libc.ino
index f4490fa2f9..a3ab6c223d 100644
--- a/tests/device/test_libc/test_libc.ino
+++ b/tests/device/test_libc/test_libc.ino
@@ -9,6 +9,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 extern "C" {
   extern void memmove_main(void);
   extern void memcpy_main(void);
diff --git a/tests/device/test_millis_mm/test_millis_mm.ino b/tests/device/test_millis_mm/test_millis_mm.ino
index e7cb59cea7..c5e25bdcdc 100644
--- a/tests/device/test_millis_mm/test_millis_mm.ino
+++ b/tests/device/test_millis_mm/test_millis_mm.ino
@@ -40,6 +40,8 @@ static uint32_t    cntref = 0;             // Ref. comparision count
 // Callback for usec counter overflow timer interrupt
 void  us_overflow_tick ( void* arg )
 {
+  (void) arg;
+
   us_cnt = system_get_time();
 
   // Check for usec counter overflow
@@ -461,11 +463,17 @@ void setup ()
 {
   Serial.begin(115200);
   WiFi.mode( WIFI_OFF );
-  us_count_init();        // Start up timer overflow sampling  
   BS_RUN(Serial);
-
 } //setup
 
+
+//---------------------------------------------------------------------------
+bool pretest ()
+{
+  us_count_init();        // Start up timer overflow sampling  
+  return true;
+} //pretest
+
 //---------------------------------------------------------------------------
 void loop(void)
 {
diff --git a/tests/device/test_newlib/test_newlib.ino b/tests/device/test_newlib/test_newlib.ino
index 46e9167347..32abbb9141 100644
--- a/tests/device/test_newlib/test_newlib.ino
+++ b/tests/device/test_newlib/test_newlib.ino
@@ -8,6 +8,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("Floating point formatting works", "[newlib]")
 {
     char buf[16];
diff --git a/tests/device/test_overrides/test_overrides.ino b/tests/device/test_overrides/test_overrides.ino
index 655f12084d..e8737f7cb7 100644
--- a/tests/device/test_overrides/test_overrides.ino
+++ b/tests/device/test_overrides/test_overrides.ino
@@ -15,11 +15,16 @@ static unsigned setup_micros;
 
 void setup()
 {
-	setup_micros = micros();
+    setup_micros = micros();
     Serial.begin(115200);
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("ADC_MODE override works", "[core]")
 {
     auto vcc = ESP.getVcc();
diff --git a/tests/device/test_ping/test_ping.ino b/tests/device/test_ping/test_ping.ino
index 1ac7c82699..a5bb98afff 100644
--- a/tests/device/test_ping/test_ping.ino
+++ b/tests/device/test_ping/test_ping.ino
@@ -10,13 +10,18 @@ void setup()
 {
     Serial.begin(115200);
     Serial.setDebugOutput(true);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.mode(WIFI_STA);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
-    BS_RUN(Serial);
+    return true;
 }
 
 static struct ping_option po;
diff --git a/tests/device/test_random/test_random.ino b/tests/device/test_random/test_random.ino
index 5d71350d5e..39563b221c 100644
--- a/tests/device/test_random/test_random.ino
+++ b/tests/device/test_random/test_random.ino
@@ -8,16 +8,21 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 
 TEST_CASE("If randomSeed is not called, random() uses hardware PRNG", "[random]")
 {
     int32_t data[32];
     srand(10);
-    for (int i = 0; i < sizeof(data)/sizeof(data[0]); ++i) {
+    for (size_t i = 0; i < sizeof(data)/sizeof(data[0]); ++i) {
         data[i] = random(0x7fffffff);
     }
     srand(10);
-    for (int i = 0; i < sizeof(data)/sizeof(data[0]); ++i) {
+    for (size_t i = 0; i < sizeof(data)/sizeof(data[0]); ++i) {
         CHECK(random(0x7fffffff) != data[i]);
     }
 }
@@ -44,7 +49,7 @@ TEST_CASE("If randomSeed is called, we get same random sequence every time", "[r
         730240988, 786466794, 1411137128, 1680096093, 
     };
     randomSeed(42);
-    for (int i = 0; i < sizeof(reference_sequence)/sizeof(reference_sequence[0]); ++i) {
+    for (size_t i = 0; i < sizeof(reference_sequence)/sizeof(reference_sequence[0]); ++i) {
         CHECK(random(0x7fffffff) == reference_sequence[i]);
     }
 }
diff --git a/tests/device/test_schedule/test_schedule.ino b/tests/device/test_schedule/test_schedule.ino
index 963635a681..26c7d114db 100644
--- a/tests/device/test_schedule/test_schedule.ino
+++ b/tests/device/test_schedule/test_schedule.ino
@@ -9,6 +9,10 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
 
 TEST_CASE("scheduled functions are executed", "[schedule]")
 {
diff --git a/tests/device/test_serial/test_serial.ino b/tests/device/test_serial/test_serial.ino
index 19481f91ff..6cdf2b2673 100644
--- a/tests/device/test_serial/test_serial.ino
+++ b/tests/device/test_serial/test_serial.ino
@@ -55,6 +55,11 @@ void setup()
   BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 void test_setup()
 {
   Serial.begin(BAUD);
diff --git a/tests/device/test_stack_in_heap/test_stack_in_heap.ino b/tests/device/test_stack_in_heap/test_stack_in_heap.ino
index 02cb11e9f1..79b513c9b3 100644
--- a/tests/device/test_stack_in_heap/test_stack_in_heap.ino
+++ b/tests/device/test_stack_in_heap/test_stack_in_heap.ino
@@ -11,6 +11,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("stack in user's HEAP ram", "[bs]")
 {
     bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
diff --git a/tests/device/test_stack_in_sys/test_stack_in_sys.ino b/tests/device/test_stack_in_sys/test_stack_in_sys.ino
index 6a1595c5ad..09270e9666 100644
--- a/tests/device/test_stack_in_sys/test_stack_in_sys.ino
+++ b/tests/device/test_stack_in_sys/test_stack_in_sys.ino
@@ -10,6 +10,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("stack in SYS ram", "[bs]")
 {
     bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
diff --git a/tests/device/test_tests/test_tests.ino b/tests/device/test_tests/test_tests.ino
index 2420805fc0..62110126b6 100644
--- a/tests/device/test_tests/test_tests.ino
+++ b/tests/device/test_tests/test_tests.ino
@@ -8,6 +8,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 
 TEST_CASE("this test runs successfully", "[bs]")
 {
diff --git a/tests/device/test_time/test_time.ino b/tests/device/test_time/test_time.ino
index 6642d3687c..a79c0c247f 100644
--- a/tests/device/test_time/test_time.ino
+++ b/tests/device/test_time/test_time.ino
@@ -8,20 +8,22 @@ BS_ENV_DECLARE();
 void setup()
 {
     Serial.begin(115200);
+    BS_RUN(Serial);
+}
+
+bool pretest()
+{
     WiFi.persistent(false);
     WiFi.begin(getenv("STA_SSID"), getenv("STA_PASS"));
     while (WiFi.status() != WL_CONNECTED) {
         delay(500);
     }
-    BS_RUN(Serial);
+    return true;
 }
 
 
 TEST_CASE("Can sync time", "[time]")
 {
-    int timezone = 3;
-    int dst = 0;
-
     configTime(3 * 3600, 0, "pool.ntp.org", "time.nist.gov");
     Serial.println("\nWaiting for time");
     unsigned timeout = 5000;
@@ -48,7 +50,7 @@ TEST_CASE("#1745 mktime and localtime", "[time]")
     const int years[] = {2012, 2013, 2014};
     const time_t timestamps[] = {1332640800, 1364176800, 1395712800};
 
-    for (int i = 0; i < sizeof(years)/sizeof(years[0]); ++i) {
+    for (size_t i = 0; i < sizeof(years)/sizeof(years[0]); ++i) {
         tm_in.tm_year = years[i] - 1900;
         tm_in.tm_mon = 2;
         tm_in.tm_mday = 25;
diff --git a/tests/device/test_umm_malloc/test_umm_malloc.ino b/tests/device/test_umm_malloc/test_umm_malloc.ino
index b805f73f7d..419b23c3c0 100644
--- a/tests/device/test_umm_malloc/test_umm_malloc.ino
+++ b/tests/device/test_umm_malloc/test_umm_malloc.ino
@@ -11,6 +11,11 @@ void setup()
     BS_RUN(Serial);
 }
 
+bool pretest()
+{
+    return true;
+}
+
 TEST_CASE("umm_info can be called", "[umm_malloc]")
 {
     umm_info(NULL, 1);