diff --git a/app/tests/benchmarks.c b/app/tests/benchmarks.c
index e5b4d9d4..a4672f99 100644
--- a/app/tests/benchmarks.c
+++ b/app/tests/benchmarks.c
@@ -247,7 +247,7 @@ __NO_INLINE static void bench_sincos(void)
 
 #endif // WITH_LIB_LIBM
 
-void benchmarks(void)
+int benchmarks(int argc, const cmd_args *argv)
 {
     bench_set_overhead();
     bench_memset();
@@ -269,5 +269,7 @@ void benchmarks(void)
 #if WITH_LIB_LIBM
     bench_sincos();
 #endif
+
+    return NO_ERROR;
 }
 
diff --git a/app/tests/clock_tests.c b/app/tests/clock_tests.c
index a5052250..c75cdc2b 100644
--- a/app/tests/clock_tests.c
+++ b/app/tests/clock_tests.c
@@ -30,7 +30,7 @@
 #include <kernel/event.h>
 #include <platform.h>
 
-void clock_tests(void)
+int clock_tests(int argc, const cmd_args *argv)
 {
     uint32_t c;
     lk_time_t t;
@@ -118,4 +118,6 @@ void clock_tests(void)
         cycles = arch_cycle_count() - cycles;
         printf("%u cycles per second\n", cycles);
     }
+
+    return NO_ERROR;
 }
diff --git a/app/tests/include/app/tests.h b/app/tests/include/app/tests.h
index 3292ac81..e0a14a17 100644
--- a/app/tests/include/app/tests.h
+++ b/app/tests/include/app/tests.h
@@ -27,13 +27,13 @@
 
 int cbuf_tests(int argc, const cmd_args *argv);
 int fibo(int argc, const cmd_args *argv);
-int port_tests(void);
+int port_tests(int argc, const cmd_args *argv);
 int spinner(int argc, const cmd_args *argv);
-int thread_tests(void);
-void benchmarks(void);
-void clock_tests(void);
-void printf_tests(void);
-void printf_tests_float(void);
+int thread_tests(int argc, const cmd_args *argv);
+int benchmarks(int argc, const cmd_args *argv);
+int clock_tests(int argc, const cmd_args *argv);
+int printf_tests(int argc, const cmd_args *argv);
+int printf_tests_float(int argc, const cmd_args *argv);
 
 #endif
 
diff --git a/app/tests/printf_tests.c b/app/tests/printf_tests.c
index e3b55bff..3a9747fa 100644
--- a/app/tests/printf_tests.c
+++ b/app/tests/printf_tests.c
@@ -21,11 +21,12 @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #include <app/tests.h>
+#include <err.h>
 #include <stdio.h>
 #include <string.h>
 #include <debug.h>
 
-void printf_tests(void)
+int printf_tests(int argc, const cmd_args *argv)
 {
     printf("printf tests\n");
 
@@ -116,11 +117,13 @@ void printf_tests(void)
     err = snprintf(buf, 15, "0123456789abcdef012345678");
     printf("snprintf returns %d\n", err);
     hexdump8(buf, sizeof(buf));
+
+    return NO_ERROR;
 }
 
 #include "float_test_vec.c"
 
-void printf_tests_float(void)
+int printf_tests_float(int argc, const cmd_args *argv)
 {
     printf("floating point printf tests\n");
 
@@ -128,6 +131,7 @@ void printf_tests_float(void)
         PRINT_FLOAT;
     }
 
+    return NO_ERROR;
 }
 
 
diff --git a/app/tests/tests.c b/app/tests/tests.c
index 2fadd8bb..55c03b42 100644
--- a/app/tests/tests.c
+++ b/app/tests/tests.c
@@ -29,14 +29,14 @@
 #include <lib/console.h>
 
 STATIC_COMMAND_START
-STATIC_COMMAND("printf_tests", "test printf", (console_cmd)&printf_tests)
-STATIC_COMMAND("printf_tests_float", "test printf with floating point", (console_cmd)&printf_tests_float)
-STATIC_COMMAND("thread_tests", "test the scheduler", (console_cmd)&thread_tests)
-STATIC_COMMAND("port_tests", "test the ports", (console_cmd)&port_tests)
-STATIC_COMMAND("clock_tests", "test clocks", (console_cmd)&clock_tests)
-STATIC_COMMAND("bench", "miscellaneous benchmarks", (console_cmd)&benchmarks)
-STATIC_COMMAND("fibo", "threaded fibonacci", (console_cmd)&fibo)
-STATIC_COMMAND("spinner", "create a spinning thread", (console_cmd)&spinner)
+STATIC_COMMAND("printf_tests", "test printf", &printf_tests)
+STATIC_COMMAND("printf_tests_float", "test printf with floating point", &printf_tests_float)
+STATIC_COMMAND("thread_tests", "test the scheduler", &thread_tests)
+STATIC_COMMAND("port_tests", "test the ports", &port_tests)
+STATIC_COMMAND("clock_tests", "test clocks", &clock_tests)
+STATIC_COMMAND("bench", "miscellaneous benchmarks", &benchmarks)
+STATIC_COMMAND("fibo", "threaded fibonacci", &fibo)
+STATIC_COMMAND("spinner", "create a spinning thread", &spinner)
 STATIC_COMMAND("cbuf_tests", "test lib/cbuf", &cbuf_tests)
 STATIC_COMMAND_END(tests);
 
@@ -48,6 +48,6 @@ static void tests_init(const struct app_descriptor *app)
 
 APP_START(tests)
 .init = tests_init,
- .flags = 0,
-  APP_END
+.flags = 0,
+APP_END
 
diff --git a/app/tests/thread_tests.c b/app/tests/thread_tests.c
index 802aa442..20c5b399 100644
--- a/app/tests/thread_tests.c
+++ b/app/tests/thread_tests.c
@@ -616,7 +616,7 @@ static void spinlock_test(void)
 #undef COUNT
 }
 
-int thread_tests(void)
+int thread_tests(int argc, const cmd_args *argv)
 {
     mutex_test();
     semaphore_test();
diff --git a/external/platform/lpc15xx/lpcopen/rules.mk b/external/platform/lpc15xx/lpcopen/rules.mk
index 57569105..c2daeceb 100644
--- a/external/platform/lpc15xx/lpcopen/rules.mk
+++ b/external/platform/lpc15xx/lpcopen/rules.mk
@@ -35,5 +35,7 @@ MODULE_SRCS += \
 	$(LOCAL_DIR)/lpc_chip_15xx/src/uart_15xx.c \
 	$(LOCAL_DIR)/lpc_chip_15xx/src/wwdt_15xx.c \
 
+MODULE_COMPILEFLAGS += -Wno-error
+
 include make/module.mk
 
diff --git a/external/platform/stellaris/ti-driverlib/driverlib/mpu.c b/external/platform/stellaris/ti-driverlib/driverlib/mpu.c
index a855336c..85ba95af 100644
--- a/external/platform/stellaris/ti-driverlib/driverlib/mpu.c
+++ b/external/platform/stellaris/ti-driverlib/driverlib/mpu.c
@@ -323,7 +323,7 @@ MPURegionSet(unsigned long ulRegion, unsigned long ulAddr,
     // Check the arguments.
     //
     ASSERT(ulRegion < 8);
-    ASSERT((ulAddr & ~0 << (((ulFlags & NVIC_MPU_ATTR_SIZE_M) >> 1) + 1))
+    ASSERT((ulAddr & ~0u << (((ulFlags & NVIC_MPU_ATTR_SIZE_M) >> 1) + 1))
             == ulAddr);
 
     //
diff --git a/external/platform/stm32f0xx/STM32F0xx_HAL_Driver/rules.mk b/external/platform/stm32f0xx/STM32F0xx_HAL_Driver/rules.mk
index 55b88aab..a81ec8ca 100644
--- a/external/platform/stm32f0xx/STM32F0xx_HAL_Driver/rules.mk
+++ b/external/platform/stm32f0xx/STM32F0xx_HAL_Driver/rules.mk
@@ -46,4 +46,6 @@ MODULE_SRCS += $(LOCAL_DIR)/stm32f0xx_hal.c \
 							 $(LOCAL_DIR)/stm32f0xx_hal_usart.c \
 							 $(LOCAL_DIR)/stm32f0xx_hal_wwdg.c
 
+MODULE_COMPILEFLAGS += -Wno-error
+
 include make/module.mk
diff --git a/external/platform/stm32f2xx/STM32F2xx_StdPeriph_Driver/src/system_stm32f2xx.c b/external/platform/stm32f2xx/STM32F2xx_StdPeriph_Driver/src/system_stm32f2xx.c
index cdc57fbd..f6d00d4a 100644
--- a/external/platform/stm32f2xx/STM32F2xx_StdPeriph_Driver/src/system_stm32f2xx.c
+++ b/external/platform/stm32f2xx/STM32F2xx_StdPeriph_Driver/src/system_stm32f2xx.c
@@ -392,8 +392,6 @@ static void SetSysClock(void)
 
     /* Wait till the main PLL is used as system clock source */
     while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
-    {
-    }
   }
   else
   { /* If HSE fails to start-up, the application will have wrong clock
diff --git a/external/platform/stm32f4xx/STM32F4xx_StdPeriph_Driver/src/system_stm32f4xx.c b/external/platform/stm32f4xx/STM32F4xx_StdPeriph_Driver/src/system_stm32f4xx.c
index 0676dc46..f58c47cf 100644
--- a/external/platform/stm32f4xx/STM32F4xx_StdPeriph_Driver/src/system_stm32f4xx.c
+++ b/external/platform/stm32f4xx/STM32F4xx_StdPeriph_Driver/src/system_stm32f4xx.c
@@ -753,8 +753,6 @@ static void SetSysClock(void)
 
     /* Wait till the main PLL is used as system clock source */
     while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
-    {
-    }
   }
   else
   { /* If HSE fails to start-up, the application will have wrong clock
diff --git a/external/platform/stm32f7xx/STM32F7xx_HAL_Driver/rules.mk b/external/platform/stm32f7xx/STM32F7xx_HAL_Driver/rules.mk
index f1212647..8204fd14 100644
--- a/external/platform/stm32f7xx/STM32F7xx_HAL_Driver/rules.mk
+++ b/external/platform/stm32f7xx/STM32F7xx_HAL_Driver/rules.mk
@@ -71,5 +71,7 @@ MODULE_SRCS += \
 
 include $(LOCAL_DIR)/CMSIS/rules.mk
 
+MODULE_COMPILEFLAGS += -Wno-error
+
 include make/module.mk
 
diff --git a/include/kernel/thread.h b/include/kernel/thread.h
index 4c40bde3..3f2c4d0d 100644
--- a/include/kernel/thread.h
+++ b/include/kernel/thread.h
@@ -186,7 +186,8 @@ void uthread_context_switch(thread_t *oldthread, thread_t *newthread);
 #endif
 
 /* called on every timer tick for the scheduler to do quantum expiration */
-enum handler_return thread_timer_tick(void);
+struct timer;
+enum handler_return thread_timer_tick(struct timer *, lk_time_t now, void *arg);
 
 /* the current thread */
 thread_t *get_current_thread(void);
diff --git a/kernel/thread.c b/kernel/thread.c
index da81e57d..08c05170 100644
--- a/kernel/thread.c
+++ b/kernel/thread.c
@@ -565,7 +565,7 @@ void thread_resched(void)
         dprintf(ALWAYS, "arch_context_switch: start preempt, cpu %d, old %p (%s), new %p (%s)\n",
                 cpu, oldthread, oldthread->name, newthread, newthread->name);
 #endif
-        timer_set_periodic(&preempt_timer[cpu], 10, (timer_callback)thread_timer_tick, NULL);
+        timer_set_periodic(&preempt_timer[cpu], 10, thread_timer_tick, NULL);
     }
 #endif
 
@@ -726,7 +726,7 @@ void thread_unblock(thread_t *t, bool resched)
         thread_resched();
 }
 
-enum handler_return thread_timer_tick(void)
+enum handler_return thread_timer_tick(struct timer *t, lk_time_t now, void *arg)
 {
     thread_t *current_thread = get_current_thread();
 
diff --git a/kernel/timer.c b/kernel/timer.c
index 00d89cac..840c8109 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -291,7 +291,7 @@ static enum handler_return timer_tick(void *arg, lk_time_t now)
 
     /* let the scheduler have a shot to do quantum expiration, etc */
     /* in case of dynamic timer, the scheduler will set up a periodic timer */
-    if (thread_timer_tick() == INT_RESCHEDULE)
+    if (thread_timer_tick(NULL, now, NULL) == INT_RESCHEDULE)
         ret = INT_RESCHEDULE;
 #endif
 
diff --git a/lib/fs/spifs/test/spifstest.c b/lib/fs/spifs/test/spifstest.c
index 218dec4d..1f8a1c6e 100644
--- a/lib/fs/spifs/test/spifstest.c
+++ b/lib/fs/spifs/test/spifstest.c
@@ -265,9 +265,9 @@ static bool test_full_toc(const char *dev_name)
         filenum[1] += (i / 10) % 10;
         filenum[2] += i % 10;
 
-        strncat(test_file_name, MNT_PATH, strlen(MNT_PATH));
-        strncat(test_file_name, "/", 1);
-        strncat(test_file_name, filenum, strlen(filenum));
+        strlcat(test_file_name, MNT_PATH, sizeof(test_file_name));
+        strlcat(test_file_name, "/", sizeof(test_file_name));
+        strlcat(test_file_name, filenum, sizeof(test_file_name));
 
         status_t status =
             fs_create_file(test_file_name, &handle, 1);
diff --git a/lib/ptable/ptable.c b/lib/ptable/ptable.c
index d056e896..54322fc7 100644
--- a/lib/ptable/ptable.c
+++ b/lib/ptable/ptable.c
@@ -735,10 +735,11 @@ status_t ptable_create_default(const char *bdev_name, uint64_t offset)
 
     /* Publish the ptable partition */
     struct ptable_entry ptable_entry;
+    memset(&ptable_entry, 0, sizeof(ptable_entry));
     ptable_entry.offset = offset;
     ptable_entry.length = len;
     ptable_entry.flags  = 0;
-    strncpy((char *)ptable_entry.name, PTABLE_PART_NAME, sizeof(ptable_entry.name));
+    strlcpy((char *)ptable_entry.name, PTABLE_PART_NAME, sizeof(ptable_entry.name));
     err = ptable_publish(&ptable_entry);
     if (err < 0) {
         LTRACEF("Failed to publish ptable partition\n");
@@ -816,10 +817,11 @@ status_t ptable_add(const char *name, uint64_t min_len, uint32_t flags)
 
     /* Attempt to publish the partition */
     struct ptable_entry ptable_entry;
+    memset(&ptable_entry, 0, sizeof(ptable_entry));
     ptable_entry.offset = part_loc;
     ptable_entry.length = min_len;
     ptable_entry.flags  = 0;
-    strncpy((char *)ptable_entry.name, name, sizeof(ptable_entry.name));
+    strlcpy((char *)ptable_entry.name, name, sizeof(ptable_entry.name));
     status_t err = ptable_publish(&ptable_entry);
     if (err < 0) {
         LTRACEF("Failed to publish\n");
diff --git a/platform/amlogic-s912d/uart.c b/platform/amlogic-s912d/uart.c
index 2ddc6fc6..c37720a0 100644
--- a/platform/amlogic-s912d/uart.c
+++ b/platform/amlogic-s912d/uart.c
@@ -106,7 +106,7 @@ int uart_getc(int port, bool wait)
     }
 }
 
-void uart_irq_handler(void)
+enum handler_return uart_irq_handler(void *arg)
 {
     while ( (UARTREG(uart_base, S912D_UART_STATUS) & S912D_UART_STATUS_RXCOUNT_MASK) > 0 ) {
         if (cbuf_space_avail(&uart_rx_buf) == 0) {
@@ -115,6 +115,8 @@ void uart_irq_handler(void)
         char c = UARTREG(uart_base, S912D_UART_RFIFO);
         cbuf_write_char(&uart_rx_buf, c,false);
     }
+
+    return INT_RESCHEDULE;
 }
 
 void uart_init_early(void)
@@ -177,4 +179,4 @@ void uart_init(void)
     // enable interrupts
     unmask_interrupt(uart_irq);
 
-}
\ No newline at end of file
+}
diff --git a/platform/mediatek/mt6735/timer.c b/platform/mediatek/mt6735/timer.c
index e2ed0cc3..25e6fb14 100644
--- a/platform/mediatek/mt6735/timer.c
+++ b/platform/mediatek/mt6735/timer.c
@@ -32,7 +32,6 @@
 
 #include <kernel/thread.h>
 
-static lk_time_t system_time = 0;
 static volatile lk_time_t ticks = 0;
 static lk_time_t tick_interval;