diff --git a/makefiles/pseudomodules.inc.mk b/makefiles/pseudomodules.inc.mk
index e71195bf85..c26a8776cd 100644
--- a/makefiles/pseudomodules.inc.mk
+++ b/makefiles/pseudomodules.inc.mk
@@ -64,7 +64,6 @@ PSEUDOMODULES += event_%
 PSEUDOMODULES += event_timeout
 PSEUDOMODULES += event_timeout_ztimer
 PSEUDOMODULES += evtimer_mbox
-PSEUDOMODULES += evtimer_on_ztimer
 PSEUDOMODULES += fatfs_vfs_format
 PSEUDOMODULES += fmt_%
 PSEUDOMODULES += gcoap_forward_proxy
diff --git a/sys/Kconfig b/sys/Kconfig
index 6a505b70e9..fc11536036 100644
--- a/sys/Kconfig
+++ b/sys/Kconfig
@@ -74,6 +74,8 @@ choice LOG
 endchoice
 
 rsource "coding/Kconfig"
+rsource "ecc/Kconfig"
+rsource "evtimer/Kconfig"
 rsource "log_color/Kconfig"
 rsource "log_printfnoformat/Kconfig"
 rsource "luid/Kconfig"
@@ -85,6 +87,7 @@ rsource "net/Kconfig"
 rsource "od/Kconfig"
 rsource "oneway-malloc/Kconfig"
 rsource "phydat/Kconfig"
+rsource "pipe/Kconfig"
 rsource "pm_layered/Kconfig"
 rsource "posix/Kconfig"
 rsource "preprocessor/Kconfig"
@@ -100,6 +103,7 @@ rsource "sema_inv/Kconfig"
 rsource "senml/Kconfig"
 rsource "seq/Kconfig"
 rsource "shell/Kconfig"
+rsource "shell_lock/Kconfig"
 rsource "ssp/Kconfig"
 rsource "test_utils/Kconfig"
 rsource "timex/Kconfig"
diff --git a/sys/Makefile.dep b/sys/Makefile.dep
index b8a0dd8b11..b27127765e 100644
--- a/sys/Makefile.dep
+++ b/sys/Makefile.dep
@@ -998,14 +998,7 @@ ifneq (,$(filter ztimer64%,$(USEMODULE)))
 endif
 
 ifneq (,$(filter evtimer,$(USEMODULE)))
-  ifneq (,$(filter evtimer_on_ztimer,$(USEMODULE)))
-    USEMODULE += ztimer_msec
-  else
-    USEMODULE += xtimer
-    ifneq (,$(filter ztimer_xtimer_compat,$(USEMODULE)))
-      USEMODULE += evtimer_on_ztimer
-    endif
-  endif
+  USEMODULE += ztimer_msec
 endif
 
 # handle xtimer's deps. Needs to be done *after* ztimer
diff --git a/sys/ecc/Kconfig b/sys/ecc/Kconfig
new file mode 100644
index 0000000000..3e257fa863
--- /dev/null
+++ b/sys/ecc/Kconfig
@@ -0,0 +1,35 @@
+# Copyright (c) 2023 Inria
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+menuconfig MODULE_ECC
+    bool "Error Correction Code (ECC) algorithms"
+    depends on TEST_KCONFIG
+    help
+        Provides Golay1412, Hamming256 and Repetition algorithms.
+
+if MODULE_ECC
+
+menu "ECC algorithms"
+
+config MODULE_ECC_GOLAY1412
+    bool "Golay1412 Error Correction Code (ECC) algorithm"
+    help
+        Provides Golay1412 ECC algorithm.
+
+config MODULE_ECC_HAMMING256
+    bool "Hamming256 Error Correction Code (ECC) algorithm"
+    help
+        Provides Hamming256 ECC algorithm.
+
+config MODULE_ECC_REPETITION
+    bool "Repetition Error Correction Code (ECC) algorithm"
+    help
+        Provides Repetition ECC algorithm.
+
+endmenu  # ECC algorithms
+
+endif
diff --git a/sys/evtimer/Kconfig b/sys/evtimer/Kconfig
new file mode 100644
index 0000000000..8cbe1cea3b
--- /dev/null
+++ b/sys/evtimer/Kconfig
@@ -0,0 +1,19 @@
+# Copyright (c) 2023 Inria
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+config MODULE_EVTIMER
+    bool "Event timer module"
+    depends on TEST_KCONFIG
+    select MODULE_ZTIMER
+    select MODULE_ZTIMER_MSEC
+
+config MODULE_EVTIMER_MBOX
+    bool "Use message box"
+    select MODULE_CORE_MBOX
+    select MODULE_EVTIMER
+    help
+        Use message box to implement event timer.
diff --git a/sys/evtimer/evtimer.c b/sys/evtimer/evtimer.c
index 4821336d37..a8f8132446 100644
--- a/sys/evtimer/evtimer.c
+++ b/sys/evtimer/evtimer.c
@@ -93,19 +93,9 @@ static void _del_event_from_list(evtimer_t *evtimer, evtimer_event_t *event)
 static void _set_timer(evtimer_t *evtimer)
 {
     evtimer_event_t *next_event = evtimer->events;
-
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
     evtimer->base = ztimer_set(ZTIMER_MSEC, &evtimer->timer, next_event->offset);
     DEBUG("evtimer: now=%" PRIu32 " ms setting ztimer to %" PRIu32 " ms\n",
           evtimer->base, next_event->offset);
-#else
-    uint64_t offset_us = (uint64_t)next_event->offset * US_PER_MS;
-
-    DEBUG("evtimer: now=%" PRIu32 " us setting xtimer to %" PRIu32 ":%" PRIu32 " us\n",
-          xtimer_now_usec(), (uint32_t)(offset_us >> 32), (uint32_t)(offset_us));
-
-    xtimer_set64(&evtimer->timer, offset_us);
-#endif
 }
 
 static void _update_timer(evtimer_t *evtimer)
@@ -114,15 +104,10 @@ static void _update_timer(evtimer_t *evtimer)
         _set_timer(evtimer);
     }
     else {
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
         ztimer_remove(ZTIMER_MSEC, &evtimer->timer);
-#else
-        xtimer_remove(&evtimer->timer);
-#endif
     }
 }
 
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
 static void _update_head_offset(evtimer_t *evtimer)
 {
     if (evtimer->events) {
@@ -137,23 +122,6 @@ static void _update_head_offset(evtimer_t *evtimer)
         evtimer->base = now;
     }
 }
-#else /* IS_USED(MODULE_EVTIMER_ON_ZTIMER) */
-static uint32_t _get_offset(xtimer_t *timer)
-{
-    uint64_t left = xtimer_left_usec(timer);
-    /* add half of 125 so integer division rounds to nearest */
-    return div_u64_by_125((left >> 3) + 62);
-}
-
-static void _update_head_offset(evtimer_t *evtimer)
-{
-    if (evtimer->events) {
-        evtimer_event_t *event = evtimer->events;
-        event->offset = _get_offset(&evtimer->timer);
-        DEBUG("evtimer: _update_head_offset(): new head offset %" PRIu32 "\n", event->offset);
-    }
-}
-#endif /* !IS_USED(MODULE_EVTIMER_ON_ZTIMER) */
 
 void evtimer_add(evtimer_t *evtimer, evtimer_event_t *event)
 {
diff --git a/sys/include/evtimer.h b/sys/include/evtimer.h
index 66ff0a5d4b..28844200c2 100644
--- a/sys/include/evtimer.h
+++ b/sys/include/evtimer.h
@@ -15,24 +15,20 @@
  *
  * @note    Experimental and likely to replaced with unified timer API
  *
- * RIOT's main timer subsystem is @ref sys_xtimer "xtimer", but for many
- * applications @ref sys_xtimer "xtimer's" 64-bit absolute time values are
- * wasteful or clumsy to use.
- *
- * Compared to @ref sys_xtimer "xtimer", evtimer offers:
+ * RIOT's main timer subsystem is @ref sys_ztimer "ztimer" but compared to
+ * @ref sys_ztimer "ztimer", evtimer offers:
  *
  * - only relative 32-bit millisecond timer values
  *   Events can be scheduled with a relative offset of up to ~49.7 days in the
  *   future.
- *   **For time-critical stuff, use @ref sys_xtimer "xtimer"!**
+ *   **For time-critical stuff, use @ref sys_ztimer "ztimer"!**
  * - more flexible, "intrusive" timer type @ref evtimer_event_t only contains
  *   the necessary fields, which can be extended as needed, and handlers define
  *   actions taken on timer triggers. Check out @ref evtimer_msg_event_t as
  *   example.
- * - uses @ref sys_xtimer "xtimer" as backend by default. Alternatively, with
- *   the pseudomodule "evtimer_on_ztimer" compiled in, evtimer is backend by
- *   @ref sys_ztimer "ZTIMER_MSEC".
- *
+ * - when a number of timeouts with the same callback function need to be
+ *   scheduled, evtimer is using less RAM (due to storing the callback function
+ *   only once), while each ztimer has a function pointer for the callback.
  * @{
  *
  * @file
@@ -48,13 +44,7 @@
 #include <stdint.h>
 #include "modules.h"
 
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
 #include "ztimer.h"
-#else
-#include "xtimer.h"
-#endif
-
-#include "timex.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -77,12 +67,8 @@ typedef void(*evtimer_callback_t)(evtimer_event_t* event);
  * @brief   Event timer
  */
 typedef struct {
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
     ztimer_t timer;                 /**< Timer */
     uint32_t base;                  /**< Absolute time the first event is built on */
-#else
-    xtimer_t timer;                 /**< Timer */
-#endif
     evtimer_callback_t callback;    /**< Handler function for this evtimer's
                                          event type */
     evtimer_event_t *events;        /**< Event queue */
@@ -128,11 +114,7 @@ void evtimer_print(const evtimer_t *evtimer);
  */
 static inline uint32_t evtimer_now_msec(void)
 {
-#if IS_USED(MODULE_EVTIMER_ON_ZTIMER)
     return ztimer_now(ZTIMER_MSEC);
-#else
-    return xtimer_now_usec64() / US_PER_MS;
-#endif
 }
 
 #ifdef __cplusplus
diff --git a/sys/include/net/gnrc/ipv6/nib/abr.h b/sys/include/net/gnrc/ipv6/nib/abr.h
index 32747c89ac..fbba10b4ea 100644
--- a/sys/include/net/gnrc/ipv6/nib/abr.h
+++ b/sys/include/net/gnrc/ipv6/nib/abr.h
@@ -26,6 +26,7 @@
 /* prevent cascading include error to xtimer if it is not compiled in or not
  * supported by board */
 #if IS_USED(MODULE_EVTIMER)
+#include "timex.h"
 #include "evtimer.h"
 #endif
 #include "net/ipv6/addr.h"
diff --git a/sys/include/shell.h b/sys/include/shell.h
index 3ef67822a5..ac8c808d38 100644
--- a/sys/include/shell.h
+++ b/sys/include/shell.h
@@ -50,7 +50,7 @@ extern "C" {
  * Instead terminate RIOT, which is also the behavior a user would
  * expect from a CLI application.
  */
-#  if defined(CPU_NATIVE) && !IS_ACTIVE(KCONFIG_USEMODULE_SHELL)
+#  if defined(CPU_NATIVE)
 #    define CONFIG_SHELL_SHUTDOWN_ON_EXIT 1
 #  else
 #    define CONFIG_SHELL_SHUTDOWN_ON_EXIT 0
diff --git a/sys/pipe/Kconfig b/sys/pipe/Kconfig
new file mode 100644
index 0000000000..3cde3abf76
--- /dev/null
+++ b/sys/pipe/Kconfig
@@ -0,0 +1,12 @@
+# Copyright (c) 2023 Inria
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+config MODULE_PIPE
+    bool "Statically allocated pipes"
+    depends on TEST_KCONFIG
+    help
+        Implementation for statically allocated pipes.
diff --git a/sys/shell_lock/Kconfig b/sys/shell_lock/Kconfig
new file mode 100644
index 0000000000..db54920df8
--- /dev/null
+++ b/sys/shell_lock/Kconfig
@@ -0,0 +1,29 @@
+# Copyright (c) 2023 Inria
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+menuconfig MODULE_SHELL_LOCK
+    bool "Shell Locking module"
+    depends on TEST_KCONFIG
+    select MODULE_ZTIMER
+    select MODULE_ZTIMER_MSEC
+
+if MODULE_SHELL_LOCK
+
+config SHELL_LOCK_PASSWORD
+    string "Lock password"
+    default "password"
+
+config SHELL_LOCK_AUTO_LOCK_TIMEOUT_MS
+    int "Timeout in ms before automatic locking"
+    default 7000
+
+endif # MODULE_SHELL_LOCK
+
+config MODULE_SHELL_LOCK_AUTO_LOCKING
+    bool "Automatic locking of the shell"
+    depends on TEST_KCONFIG
+    select MODULE_SHELL_LOCK
diff --git a/sys/ztimer/Makefile.dep b/sys/ztimer/Makefile.dep
index eec51b70b0..e20ba7e2a7 100644
--- a/sys/ztimer/Makefile.dep
+++ b/sys/ztimer/Makefile.dep
@@ -11,13 +11,6 @@ ifneq (,$(filter ztimer,$(USEMODULE)))
   DEFAULT_MODULE += ztimer_init
 endif
 
-# unless ztimer_xtimer_compat is used, make xtimer use ztimer_usec as backend.
-ifneq (,$(filter ztimer,$(USEMODULE)))
-  ifneq (,$(filter evtimer,$(USEMODULE)))
-    USEMODULE += evtimer_on_ztimer
-  endif
-endif
-
 ifneq (,$(filter ztimer_xtimer_compat,$(USEMODULE)))
   USEMODULE += ztimer_usec
 endif
@@ -27,11 +20,6 @@ ifneq (,$(filter ztimer64_xtimer_compat,$(USEMODULE)))
   USEMODULE += ztimer_xtimer_compat
 endif
 
-# make evtimer use ztimer_msec as low level timer
-ifneq (,$(filter evtimer_on_ztimer,$(USEMODULE)))
-  USEMODULE += ztimer_msec
-endif
-
 ifneq (,$(filter ztimer_%,$(USEMODULE)))
   USEMODULE += ztimer_core
   USEMODULE += ztimer_extend
diff --git a/tests/net/gnrc_mac_timeout/Makefile b/tests/net/gnrc_mac_timeout/Makefile
index 6a78094e52..9675b41cf2 100644
--- a/tests/net/gnrc_mac_timeout/Makefile
+++ b/tests/net/gnrc_mac_timeout/Makefile
@@ -1,5 +1,6 @@
 include ../Makefile.net_common
 
+USEMODULE += ztimer_msec
 USEMODULE += gnrc_mac
 
 include $(RIOTBASE)/Makefile.include
diff --git a/tests/net/gnrc_mac_timeout/main.c b/tests/net/gnrc_mac_timeout/main.c
index cd00eed78f..78e895a0fd 100644
--- a/tests/net/gnrc_mac_timeout/main.c
+++ b/tests/net/gnrc_mac_timeout/main.c
@@ -23,7 +23,7 @@
 #include "net/gnrc/mac/timeout.h"
 #include "thread.h"
 #include "msg.h"
-#include "xtimer.h"
+#include "ztimer.h"
 
 #define TIMEOUT_COUNT    3
 #define TIMEOUT_1_DURATION    1000
@@ -34,7 +34,7 @@ static gnrc_mac_timeout_event_t test_timeouts[TIMEOUT_COUNT];
 static gnrc_mac_timeout_type_t timeout_1;
 static gnrc_mac_timeout_type_t timeout_2;
 static gnrc_mac_timeout_type_t timeout_3;
-static uint32_t start_time;
+static ztimer_now_t start_time;
 
 static char worker_stack[THREAD_STACKSIZE_MAIN];
 
@@ -47,10 +47,10 @@ void *worker_thread(void *arg)
 
     while (1) {
         msg_t m;
-        uint32_t now;
+        ztimer_now_t now;
 
         msg_receive(&m);
-        now = xtimer_now_usec() / US_PER_MS;
+        now = ztimer_now(ZTIMER_MSEC);
 
         if (gnrc_mac_timeout_is_expired(&mac_timeout, timeout_1)) {
             printf("At %6" PRIu32 " ms received msg %i: timeout_1 (set at %" PRIu32 " ms) expired, "
@@ -102,7 +102,7 @@ int main(void)
     timeout_2 = -2;
     timeout_3 = -3;
 
-    start_time = xtimer_now_usec() / US_PER_MS;
+    start_time = ztimer_now(ZTIMER_MSEC);
     gnrc_mac_init_timeouts(&mac_timeout, test_timeouts, TIMEOUT_COUNT);
     gnrc_mac_set_timeout(&mac_timeout, timeout_1, TIMEOUT_1_DURATION, pid);
     gnrc_mac_set_timeout(&mac_timeout, timeout_2, TIMEOUT_2_DURATION, pid);
diff --git a/tests/net/gnrc_netif/main.c b/tests/net/gnrc_netif/main.c
index 34fff1e905..caf86553e1 100644
--- a/tests/net/gnrc_netif/main.c
+++ b/tests/net/gnrc_netif/main.c
@@ -38,7 +38,6 @@
 #include "net/netif.h"
 #include "test_utils/expect.h"
 #include "utlist.h"
-#include "xtimer.h"
 
 #define ETHERNET_STACKSIZE          (THREAD_STACKSIZE_MAIN)
 #define IEEE802154_STACKSIZE        (THREAD_STACKSIZE_MAIN)
diff --git a/tests/sys/evtimer_mbox/app.config.test b/tests/sys/evtimer_mbox/app.config.test
new file mode 100644
index 0000000000..4f02c158e2
--- /dev/null
+++ b/tests/sys/evtimer_mbox/app.config.test
@@ -0,0 +1 @@
+CONFIG_MODULE_EVTIMER_MBOX=y
diff --git a/tests/sys/evtimer_msg/Makefile b/tests/sys/evtimer_msg/Makefile
index aacc3125a5..007687a90c 100644
--- a/tests/sys/evtimer_msg/Makefile
+++ b/tests/sys/evtimer_msg/Makefile
@@ -1,7 +1,7 @@
 include ../Makefile.sys_common
 
 USEMODULE += evtimer
-USEMODULE += xtimer
+USEMODULE += ztimer_msec
 
 # This test randomly fails on `native` so disable it from CI
 TEST_ON_CI_BLACKLIST += native
diff --git a/tests/sys/evtimer_msg/app.config.test b/tests/sys/evtimer_msg/app.config.test
new file mode 100644
index 0000000000..77160ead67
--- /dev/null
+++ b/tests/sys/evtimer_msg/app.config.test
@@ -0,0 +1 @@
+CONFIG_MODULE_EVTIMER=y
diff --git a/tests/sys/evtimer_msg/main.c b/tests/sys/evtimer_msg/main.c
index 961e2f5c8e..59e4f6de14 100644
--- a/tests/sys/evtimer_msg/main.c
+++ b/tests/sys/evtimer_msg/main.c
@@ -23,7 +23,7 @@
 #include "evtimer_msg.h"
 #include "thread.h"
 #include "msg.h"
-#include "xtimer.h"
+#include "ztimer.h"
 
 static char worker_stack[THREAD_STACKSIZE_MAIN];
 static evtimer_t evtimer;
@@ -111,7 +111,7 @@ int main(void)
            NEVENTS);
 
     /* The last offset is the largest, wait for it and a tiny bit more */
-    xtimer_msleep((offsets[3] + 10));
+    ztimer_sleep(ZTIMER_MSEC, (offsets[3] + 10));
     puts("By now all msgs should have been received");
     puts("If yes, the tests were successful");
 }
diff --git a/tests/sys/evtimer_underflow/Makefile b/tests/sys/evtimer_underflow/Makefile
index 485222d0a7..071591b0b1 100644
--- a/tests/sys/evtimer_underflow/Makefile
+++ b/tests/sys/evtimer_underflow/Makefile
@@ -1,7 +1,7 @@
 include ../Makefile.sys_common
 
 USEMODULE += evtimer
-USEMODULE += xtimer
+USEMODULE += ztimer_msec
 
 # microbit qemu lacks rtt
 TEST_ON_CI_BLACKLIST += microbit
diff --git a/tests/sys/evtimer_underflow/app.config.test b/tests/sys/evtimer_underflow/app.config.test
new file mode 100644
index 0000000000..77160ead67
--- /dev/null
+++ b/tests/sys/evtimer_underflow/app.config.test
@@ -0,0 +1 @@
+CONFIG_MODULE_EVTIMER=y
diff --git a/tests/sys/evtimer_underflow/main.c b/tests/sys/evtimer_underflow/main.c
index 89768ee4ec..43ecfb2122 100644
--- a/tests/sys/evtimer_underflow/main.c
+++ b/tests/sys/evtimer_underflow/main.c
@@ -23,7 +23,7 @@
 #include "evtimer_msg.h"
 #include "thread.h"
 #include "msg.h"
-#include "xtimer.h"
+#include "ztimer.h"
 
 #define WORKER_MSG_QUEUE_SIZE   (8)
 
@@ -61,7 +61,7 @@ void *worker_thread(void *arg)
 
 void sleep_msec(uint16_t t)
 {
-    xtimer_msleep(t);
+    ztimer_sleep(ZTIMER_MSEC, t);
 }
 
 int main(void)
diff --git a/tests/sys/pipe/app.config.test b/tests/sys/pipe/app.config.test
new file mode 100644
index 0000000000..18cf9c2314
--- /dev/null
+++ b/tests/sys/pipe/app.config.test
@@ -0,0 +1 @@
+CONFIG_MODULE_PIPE=y
diff --git a/tests/sys/shell_lock/Makefile b/tests/sys/shell_lock/Makefile
index 6b67361fde..a9da2d0033 100644
--- a/tests/sys/shell_lock/Makefile
+++ b/tests/sys/shell_lock/Makefile
@@ -7,8 +7,10 @@ USEMODULE += shell_cmds_default
 USEMODULE += shell_lock
 USEMODULE += shell_lock_auto_locking
 
+ifneq (1,$(TEST_KCONFIG))
 CFLAGS += -DCONFIG_SHELL_LOCK_PASSWORD=\"password\"
 CFLAGS += -DCONFIG_SHELL_LOCK_AUTO_LOCK_TIMEOUT_MS=7000
+endif
 
 # This config defaults to 1 on native, such that pm_off() would be called as soon as
 # shell_run_once is terminated in shell_run_forever. We do not want this behavior for this test.
diff --git a/tests/sys/shell_lock/app.config.test b/tests/sys/shell_lock/app.config.test
new file mode 100644
index 0000000000..c11575af5a
--- /dev/null
+++ b/tests/sys/shell_lock/app.config.test
@@ -0,0 +1,6 @@
+CONFIG_MODULE_SHELL=y
+CONFIG_MODULE_SHELL_CMDS_DEFAULT=y
+CONFIG_MODULE_SHELL_LOCK=y
+CONFIG_MODULE_SHELL_LOCK_AUTO_LOCKING=y
+CONFIG_MODULE_TEST_UTILS_INTERACTIVE_SYNC_SHELL=n
+CONFIG_SHELL_SHUTDOWN_ON_EXIT=n