cc3200: Implement safe boot pin and system led behaviour.

The safe boot pin, when pulled high during reset rolls back the
firmware to the "factory" image and skips execution of 'boot.py'
and 'main.py'. This is useful to recover from a crash condition.
The system led is used mostly to signal errors.

10 files changed, 172 insertions, 75 deletions

diff --git a/cc3200/boards/LAUNCHXL/mpconfigboard.h b/cc3200/boards/LAUNCHXL/mpconfigboard.h
index c4472c77b..2d12d4f6c 100644
--- a/cc3200/boards/LAUNCHXL/mpconfigboard.h
+++ b/cc3200/boards/LAUNCHXL/mpconfigboard.h
@@ -37,3 +37,12 @@
 #define MICROPY_STDIO_UART                          PYB_UART_0
 #define MICROPY_STDIO_UART_BAUD                     115200
 
+#define MICROPY_SYS_LED_PRCM                        PRCM_GPIOA1
+#define MICROPY_SAFE_BOOT_PRCM                        PRCM_GPIOA2
+#define MICROPY_SYS_LED_PORT                        GPIOA1_BASE
+#define MICROPY_SAFE_BOOT_PORT                        GPIOA2_BASE
+#define MICROPY_SYS_LED_PIN_NUM                     PIN_64      // GPIO9
+#define MICROPY_SAFE_BOOT_PIN_NUM                     PIN_15      // GPIO22
+#define MICROPY_SYS_LED_PORT_PIN                    GPIO_PIN_1
+#define MICROPY_SAFE_BOOT_PORT_PIN                    GPIO_PIN_6
+
diff --git a/cc3200/bootmgr/bootloader.mk b/cc3200/bootmgr/bootloader.mk
index 64d7f671a..1f687d9b8 100644
--- a/cc3200/bootmgr/bootloader.mk
+++ b/cc3200/bootmgr/bootloader.mk
@@ -5,6 +5,7 @@ BOOT_INC += -Ibootmgr/sl
 BOOT_INC += -Ihal
 BOOT_INC += -Ihal/inc
 BOOT_INC += -I../drivers/cc3100/inc
+BOOT_INC += -Imisc
 BOOT_INC += -Imods
 BOOT_INC += -Isimplelink
 BOOT_INC += -Isimplelink/oslib
@@ -39,6 +40,10 @@ BOOT_CC3100_SRC_C = $(addprefix drivers/cc3100/,\
 	src/wlan.c \
 	)
 
+BOOT_MISC_SRC_C = $(addprefix misc/,\
+	mperror.c \
+	)
+
 BOOT_MODS_SRC_C = $(addprefix mods/,\
 	pybwdt.c \
 	)
@@ -68,7 +73,7 @@ BOOT_STM_SRC_C = $(addprefix stmhal/,\
 	)
 	
 OBJ  = $(addprefix $(BUILD)/, $(BOOT_HAL_SRC_C:.c=.o) $(BOOT_MODS_SRC_C:.c=.o) $(BOOT_SL_SRC_C:.c=.o) $(BOOT_CC3100_SRC_C:.c=.o) $(BOOT_UTIL_SRC_C:.c=.o))
-OBJ += $(addprefix $(BUILD)/, $(BOOT_MAIN_SRC_C:.c=.o) $(BOOT_MAIN_SRC_S:.s=.o) $(BOOT_PY_SRC_C:.c=.o) $(BOOT_STM_SRC_C:.c=.o))
+OBJ += $(addprefix $(BUILD)/, $(BOOT_MISC_SRC_C:.c=.o) $(BOOT_MAIN_SRC_C:.c=.o) $(BOOT_MAIN_SRC_S:.s=.o) $(BOOT_PY_SRC_C:.c=.o) $(BOOT_STM_SRC_C:.c=.o))
 
 # Add the linker script
 LINKER_SCRIPT = bootmgr/bootmgr.lds
@@ -90,6 +95,7 @@ ifeq ($(BTYPE), debug)
 CFLAGS += -DDEBUG=DEBUG
 # Optimize the stable sources only
 $(BUILD)/hal/%.o: CFLAGS += -Os
+$(BUILD)/misc/%.o: CFLAGS += -Os
 $(BUILD)/simplelink/%.o: CFLAGS += -Os
 $(BUILD)/drivers/cc3100/%.o: CFLAGS += -Os
 $(BUILD)/py/%.o: CFLAGS += -Os
diff --git a/cc3200/bootmgr/main.c b/cc3200/bootmgr/main.c
index 839e23ecd..0e7ecd01b 100644
--- a/cc3200/bootmgr/main.c
+++ b/cc3200/bootmgr/main.c
@@ -26,8 +26,10 @@
 
 #include <stdint.h>
 #include <stdbool.h>
-
 #include <std.h>
+
+#include "py/mpconfig.h"
+#include MICROPY_HAL_H
 #include "hw_ints.h"
 #include "hw_types.h"
 #include "hw_gpio.h"
@@ -50,6 +52,7 @@
 #include "cc3200_hal.h"
 #include "debug.h"
 #include "pybwdt.h"
+#include "mperror.h"
 
 
 //*****************************************************************************
@@ -60,19 +63,11 @@
 #define BOOTMGR_HASH_SIZE                   32
 #define BOOTMGR_BUFF_SIZE                   512
 
-#define BOOTMGR_WAIT_SAFE_MODE_MS           2000
-#define BOOTMGR_WAIT_SAFE_MODE_TOOGLE_MS    250
-
-#define BOOTMGR_SAFE_MODE_ENTER_MS          1000
-#define BOOTMGR_SAFE_MODE_ENTER_TOOGLE_MS   100
-
-#define BOOTMGR_PINS_PRCM                   PRCM_GPIOA3
-#define BOOTMGR_PINS_PORT                   GPIOA3_BASE
-#define BOOTMGR_LED_PIN_NUM                 PIN_21
-#define BOOTMGR_SFE_PIN_NUM                 PIN_18
-#define BOOTMGR_LED_PORT_PIN                GPIO_PIN_1      // GPIO25
-#define BOOTMGR_SFE_PORT_PIN                GPIO_PIN_4      // GPIO28
+#define BOOTMGR_WAIT_SAFE_MODE_MS           1600
+#define BOOTMGR_WAIT_SAFE_MODE_TOOGLE_MS    200
 
+#define BOOTMGR_SAFE_MODE_ENTER_MS          700
+#define BOOTMGR_SAFE_MODE_ENTER_TOOGLE_MS   70
 
 //*****************************************************************************
 // Exported functions declarations
@@ -159,18 +154,12 @@ static void bootmgr_board_init(void) {
     // Enable the Data Hashing Engine
     HASH_Init();
 
-    // Enable GPIOA3 Peripheral Clock
-    MAP_PRCMPeripheralClkEnable(BOOTMGR_PINS_PRCM, PRCM_RUN_MODE_CLK);
-
-    // Configure the bld
-    MAP_PinTypeGPIO(BOOTMGR_LED_PIN_NUM, PIN_MODE_0, false);
-    MAP_PinConfigSet(BOOTMGR_LED_PIN_NUM, PIN_STRENGTH_6MA, PIN_TYPE_STD);
-    MAP_GPIODirModeSet(BOOTMGR_PINS_PORT, BOOTMGR_LED_PORT_PIN, GPIO_DIR_MODE_OUT);
+    // Init the system led and the system switch
+    mperror_init0();
 
-    // Configure the safe mode pin
-    MAP_PinTypeGPIO(BOOTMGR_SFE_PIN_NUM, PIN_MODE_0, false);
-    MAP_PinConfigSet(BOOTMGR_SFE_PIN_NUM, PIN_STRENGTH_4MA, PIN_TYPE_STD_PU);
-    MAP_GPIODirModeSet(BOOTMGR_PINS_PORT, BOOTMGR_SFE_PORT_PIN, GPIO_DIR_MODE_IN);
+    // clear the safe boot request, since we should not trust
+    // the register's state after reset
+    mperror_clear_safe_boot();
 }
 
 //*****************************************************************************
@@ -252,13 +241,14 @@ static void bootmgr_load_and_execute (_u8 *image) {
 //*****************************************************************************
 static bool safe_mode_boot (void) {
     _u32 count = 0;
-    while (!MAP_GPIOPinRead(BOOTMGR_PINS_PORT, BOOTMGR_SFE_PORT_PIN) &&
-            ((BOOTMGR_WAIT_SAFE_MODE_TOOGLE_MS * count++) < BOOTMGR_WAIT_SAFE_MODE_MS)) {
+    while (MAP_GPIOPinRead(MICROPY_SAFE_BOOT_PORT, MICROPY_SAFE_BOOT_PORT_PIN) &&
+           ((BOOTMGR_WAIT_SAFE_MODE_TOOGLE_MS * count++) < BOOTMGR_WAIT_SAFE_MODE_MS)) {
         // toogle the led
-        MAP_GPIOPinWrite(BOOTMGR_PINS_PORT, BOOTMGR_LED_PORT_PIN, ~MAP_GPIOPinRead(GPIOA3_BASE, BOOTMGR_LED_PORT_PIN));
+        MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, ~MAP_GPIOPinRead(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN));
         UtilsDelay(UTILS_DELAY_US_TO_COUNT(BOOTMGR_WAIT_SAFE_MODE_TOOGLE_MS * 1000));
     }
-    return MAP_GPIOPinRead(BOOTMGR_PINS_PORT, BOOTMGR_SFE_PORT_PIN) ? false : true;
+    mperror_deinit_sfe_pin();
+    return MAP_GPIOPinRead(MICROPY_SAFE_BOOT_PORT, MICROPY_SAFE_BOOT_PORT_PIN) ? true : false;
 }
 
 //*****************************************************************************
@@ -268,14 +258,16 @@ static void bootmgr_image_loader(sBootInfo_t *psBootInfo) {
     _i32 fhandle;
     if (safe_mode_boot()) {
          _u32 count = 0;
-         while ((BOOTMGR_SAFE_MODE_ENTER_TOOGLE_MS * count++) > BOOTMGR_SAFE_MODE_ENTER_MS) {
+         while ((BOOTMGR_SAFE_MODE_ENTER_TOOGLE_MS * count++) < BOOTMGR_SAFE_MODE_ENTER_MS) {
              // toogle the led
-             MAP_GPIOPinWrite(BOOTMGR_PINS_PORT, BOOTMGR_LED_PORT_PIN, ~MAP_GPIOPinRead(GPIOA3_BASE, BOOTMGR_LED_PORT_PIN));
+             MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, ~MAP_GPIOPinRead(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN));
              UtilsDelay(UTILS_DELAY_US_TO_COUNT(BOOTMGR_SAFE_MODE_ENTER_TOOGLE_MS * 1000));
          }
          psBootInfo->ActiveImg = IMG_ACT_FACTORY;
          // turn the led off
-         MAP_GPIOPinWrite(BOOTMGR_PINS_PORT, BOOTMGR_LED_PORT_PIN, 0);
+         MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, 0);
+         // request a safe boot to the application
+         mperror_request_safe_boot();
     }
     // do we have a new update image that needs to be verified?
     else if ((psBootInfo->ActiveImg == IMG_ACT_UPDATE) && (psBootInfo->Status == IMG_STATUS_CHECK)) {
@@ -350,7 +342,7 @@ int main (void) {
     // could not be loaded, so, loop forever and signal the crash to the user
     while (true) {
         // keep the bld on
-        MAP_GPIOPinWrite(BOOTMGR_PINS_PORT, BOOTMGR_LED_PORT_PIN, BOOTMGR_LED_PORT_PIN);
+        MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, MICROPY_SYS_LED_PORT_PIN);
         __asm volatile("    dsb      \n"
                        "    isb      \n"
                        "    wfi      \n");
diff --git a/cc3200/main.c b/cc3200/main.c
index 6f0ce3f1b..24a42c524 100644
--- a/cc3200/main.c
+++ b/cc3200/main.c
@@ -63,7 +63,7 @@ int main (void) {
     // Initialize the clocks and the interrupt system
     HAL_SystemInit();
 
-    // Start the watchdog
+    // Init the watchdog
     pybwdt_init0();
 
 #ifdef DEBUG
diff --git a/cc3200/misc/FreeRTOSHooks.c b/cc3200/misc/FreeRTOSHooks.c
index 4268980d6..9383000b0 100644
--- a/cc3200/misc/FreeRTOSHooks.c
+++ b/cc3200/misc/FreeRTOSHooks.c
@@ -35,6 +35,7 @@
 #include "pybuart.h"
 #include "osi.h"
 #include "pybwdt.h"
+#include "mperror.h"
 
 
 //*****************************************************************************
@@ -66,15 +67,13 @@ void vApplicationIdleHook (void)
 void vApplicationMallocFailedHook (void)
 {
 #ifdef DEBUG
-    // Break into the debugger
+    // break into the debugger
     __asm volatile ("bkpt #0  \n");
-
-    printf("\nFATAL ERROR: FreeRTOS malloc failed!\n");
 #endif
 
     for ( ; ; )
     {
-        // TODO: Blink the BLD
+        __fatal_error("FreeRTOS malloc failed!");
     }
 }
 
@@ -92,13 +91,11 @@ void vApplicationStackOverflowHook (OsiTaskHandle *pxTask, signed char *pcTaskNa
 #ifdef DEBUG
     // Break into the debugger
     __asm volatile ("bkpt #0  \n");
-
-    printf("\nFATAL ERROR: Application: %s stack overflow!\n", pcTaskName);
 #endif
 
     for ( ; ; )
     {
-        // TODO: Blink the BLD
+        __fatal_error("Stack overflow!");
     }
 }
 
diff --git a/cc3200/misc/mperror.c b/cc3200/misc/mperror.c
index a615a0f06..bfb17a2b4 100644
--- a/cc3200/misc/mperror.c
+++ b/cc3200/misc/mperror.c
@@ -32,12 +32,78 @@
 #include "py/mpconfig.h"
 #include MICROPY_HAL_H
 #include "py/obj.h"
-#include "inc/hw_memmap.h"
+#include "hw_ints.h"
+#include "hw_types.h"
+#include "hw_gpio.h"
+#include "hw_memmap.h"
+#include "hw_gprcm.h"
+#include "hw_common_reg.h"
+#include "pin.h"
+#include "gpio.h"
+#include "rom.h"
+#include "rom_map.h"
+#include "prcm.h"
 #include "pybuart.h"
 #include "utils.h"
 
 
+#define MPERROR_TOOGLE_MS                           (200)
+#define MPERROR_SIGNAL_ERROR_MS                     (2000)
+
+#define MPERROR_SAFE_BOOT_REG_IDX                   (0)
+
+
+void mperror_init0 (void) {
+    // Enable SYS GPIOs peripheral clocks
+    MAP_PRCMPeripheralClkEnable(MICROPY_SYS_LED_PRCM, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK);
+#ifdef BOOTLOADER
+    MAP_PRCMPeripheralClkEnable(MICROPY_SAFE_BOOT_PRCM, PRCM_RUN_MODE_CLK | PRCM_SLP_MODE_CLK);
+#endif
+
+    // Configure the bld
+    MAP_PinTypeGPIO(MICROPY_SYS_LED_PIN_NUM, PIN_MODE_0, false);
+    MAP_PinConfigSet(MICROPY_SYS_LED_PIN_NUM, PIN_STRENGTH_6MA, PIN_TYPE_STD);
+    MAP_GPIODirModeSet(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, GPIO_DIR_MODE_OUT);
+
+#ifdef BOOTLOADER
+    // Configure the safe boot pin
+    MAP_PinTypeGPIO(MICROPY_SAFE_BOOT_PIN_NUM, PIN_MODE_0, false);
+    MAP_PinConfigSet(MICROPY_SAFE_BOOT_PIN_NUM, PIN_STRENGTH_4MA, PIN_TYPE_STD_PD);
+    MAP_GPIODirModeSet(MICROPY_SAFE_BOOT_PORT, MICROPY_SAFE_BOOT_PORT_PIN, GPIO_DIR_MODE_IN);
+#endif
+}
+
+void mperror_deinit_sfe_pin (void) {
+    // disable the pull-down
+    MAP_PinConfigSet(MICROPY_SAFE_BOOT_PIN_NUM, PIN_STRENGTH_4MA, PIN_TYPE_STD);
+}
+
+void mperror_signal_error (void) {
+    uint32_t count = 0;
+    while ((MPERROR_TOOGLE_MS * count++) > MPERROR_SIGNAL_ERROR_MS) {
+        // toogle the led
+        MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, ~MAP_GPIOPinRead(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN));
+        UtilsDelay(UTILS_DELAY_US_TO_COUNT(MPERROR_TOOGLE_MS * 1000));
+    }
+}
+
+void mperror_request_safe_boot (void) {
+    MAP_PRCMOCRRegisterWrite(MPERROR_SAFE_BOOT_REG_IDX, 1);
+}
+
+void mperror_clear_safe_boot (void) {
+    MAP_PRCMOCRRegisterWrite(MPERROR_SAFE_BOOT_REG_IDX, 0);
+}
+
+// returns the last state of the safe boot request and clears the register
+bool mperror_safe_boot_requested (void) {
+    bool ret = MAP_PRCMOCRRegisterRead(MPERROR_SAFE_BOOT_REG_IDX);
+    mperror_clear_safe_boot();
+    return ret;
+}
+
 void NORETURN __fatal_error(const char *msg) {
+#ifdef DEBUG
     if (msg != NULL) {
         // wait for 20ms
         UtilsDelay(UTILS_DELAY_US_TO_COUNT(20000));
@@ -45,6 +111,9 @@ void NORETURN __fatal_error(const char *msg) {
         mp_hal_stdout_tx_str(msg);
         mp_hal_stdout_tx_str("\r\n");
     }
+#endif
+    // signal the crash with the system led
+    MAP_GPIOPinWrite(MICROPY_SYS_LED_PORT, MICROPY_SYS_LED_PORT_PIN, MICROPY_SYS_LED_PORT_PIN);
     for ( ;; ) {__WFI();}
 }
 
@@ -63,4 +132,3 @@ void nlr_jump_fail(void *val) {
     __fatal_error(NULL);
 #endif
 }
-
diff --git a/cc3200/misc/mperror.h b/cc3200/misc/mperror.h
index 89a2abe8e..827d00a9f 100644
--- a/cc3200/misc/mperror.h
+++ b/cc3200/misc/mperror.h
@@ -25,8 +25,16 @@
  * THE SOFTWARE.
  */
 
-#ifdef DEBUG
+#ifndef MPERROR_H_
+#define MPERROR_H_
+
 extern void NORETURN __fatal_error(const char *msg);
-#else
-#define __fatal_error(...)     for ( ;; ) {__WFI();}
-#endif
+
+void mperror_init0 (void);
+void mperror_deinit_sfe_pin (void);
+void mperror_signal_error (void);
+void mperror_request_safe_boot (void);
+void mperror_clear_safe_boot (void);
+bool mperror_safe_boot_requested (void);
+
+#endif // MPERROR_H_
diff --git a/cc3200/mods/pybextint.c b/cc3200/mods/pybextint.c
index a98dbdba7..c135c4f56 100644
--- a/cc3200/mods/pybextint.c
+++ b/cc3200/mods/pybextint.c
@@ -46,6 +46,7 @@
 #include "mpexception.h"
 #include "interrupt.h"
 #include "cc3200_asm.h"
+#include "mperror.h"
 
 /// \moduleref pyb
 /// \class ExtInt - configure I/O pins to interrupt on external events
@@ -218,8 +219,8 @@ STATIC void ExecuteIntCallback (extint_obj_t *self) {
             extint_disable(self);
             // printing an exception here will cause a stack overflow that ends up in a
             // hard fault so, is better to signal the uncaught (probably non-recoverable)
-            // exception by blinkg the BLD
-            // TODO: Blink the BLD
+            // exception by blinkg the system led
+            mperror_signal_error();
         }
         gc_unlock();
         enable_irq(primsk);
diff --git a/cc3200/mptask.c b/cc3200/mptask.c
index 90bb7e9a2..733191969 100644
--- a/cc3200/mptask.c
+++ b/cc3200/mptask.c
@@ -96,12 +96,20 @@ void TASK_Micropython (void *pvParameters) {
     // Initialize the garbage collector with the top of our stack
     uint32_t sp = gc_helper_get_sp();
     gc_collect_init (sp);
+    bool safeboot;
     FRESULT res;
 
 #if MICROPY_HW_ENABLE_RTC
     pybrtc_init();
 #endif
 
+#ifdef DEBUG
+    mperror_init0();
+    safeboot = false;
+#else
+    safeboot = mperror_safe_boot_requested();
+#endif
+
     // Create the simple link spawn task
     ASSERT (OSI_OK == VStartSimpleLinkSpawnTask(SIMPLELINK_SPAWN_TASK_PRIORITY));
 
@@ -170,16 +178,19 @@ soft_reset:
     // reset config variables; they should be set by boot.py
     MP_STATE_PORT(pyb_config_main) = MP_OBJ_NULL;
 
-    // run boot.py, if it exists
-    const char *boot_py = "BOOT.PY";
-    res = f_stat(boot_py, NULL);
-    if (res == FR_OK) {
-        int ret = pyexec_file(boot_py);
-        if (ret & PYEXEC_FORCED_EXIT) {
-            goto soft_reset_exit;
-        }
-        if (!ret) {
-            // TODO: Flash some LEDs
+    if (!safeboot) {
+        // run boot.py, if it exists
+        const char *boot_py = "BOOT.PY";
+        res = f_stat(boot_py, NULL);
+        if (res == FR_OK) {
+            int ret = pyexec_file(boot_py);
+            if (ret & PYEXEC_FORCED_EXIT) {
+                goto soft_reset_exit;
+            }
+            if (!ret) {
+                // flash the system led
+                mperror_signal_error();
+            }
         }
     }
 
@@ -189,22 +200,25 @@ soft_reset:
 
     // At this point everything is fully configured and initialised.
 
-    // Run the main script from the current directory.
-    if (pyexec_mode_kind == PYEXEC_MODE_FRIENDLY_REPL) {
-        const char *main_py;
-        if (MP_STATE_PORT(pyb_config_main) == MP_OBJ_NULL) {
-            main_py = "MAIN.PY";
-        } else {
-            main_py = mp_obj_str_get_str(MP_STATE_PORT(pyb_config_main));
-        }
-        res = f_stat(main_py, NULL);
-        if (res == FR_OK) {
-            int ret = pyexec_file(main_py);
-            if (ret & PYEXEC_FORCED_EXIT) {
-                goto soft_reset_exit;
+    if (!safeboot) {
+        // Run the main script from the current directory.
+        if (pyexec_mode_kind == PYEXEC_MODE_FRIENDLY_REPL) {
+            const char *main_py;
+            if (MP_STATE_PORT(pyb_config_main) == MP_OBJ_NULL) {
+                main_py = "MAIN.PY";
+            } else {
+                main_py = mp_obj_str_get_str(MP_STATE_PORT(pyb_config_main));
             }
-            if (!ret) {
-                // TODO: Flash some LEDs
+            res = f_stat(main_py, NULL);
+            if (res == FR_OK) {
+                int ret = pyexec_file(main_py);
+                if (ret & PYEXEC_FORCED_EXIT) {
+                    goto soft_reset_exit;
+                }
+                if (!ret) {
+                    // flash the system led
+                    mperror_signal_error();
+                }
             }
         }
     }
diff --git a/cc3200/telnet/telnet.c b/cc3200/telnet/telnet.c
index 7d11df913..31037aed2 100644
--- a/cc3200/telnet/telnet.c
+++ b/cc3200/telnet/telnet.c
@@ -36,6 +36,7 @@
 #include "debug.h"
 #include "mpexception.h"
 #include "serverstask.h"
+#include "mperror.h"
 #include "genhdr/py-version.h"
 
 
@@ -461,7 +462,8 @@ static bool telnet_send_with_retries (int16_t sd, const void *pBuf, int16_t len)
         } while (++retries <= TELNET_TX_RETRIES_MAX);
     }
     else {
-        // TODO: blink the BLD
+        // blink the system led
+        mperror_signal_error();
     }
 
     return false;