Brownout works (in as far brownout can work...), int wdt works.

components/esp32/Kconfig

@@ -151,16 +151,13 @@ config INT_WDT
         interrupt handler did not return. It will try to invoke the panic handler first and failing that
         reset the SoC.
 
-config INT_WDT_TIMEOUT_MS_MIN
-    default (2000/CONFIG_FREERTOS_HZ)
-
 config INT_WDT_TIMEOUT_MS
     int "Interrupt watchdog timeout (ms)"
     depends on INT_WDT
-    default 100
-    range INT_WDT_TIMEOUT_MS_MIN 10000
+    default 10
+    range INT_WDT_TIMEOUT_MIN 10000
     help
-        The timeout of the watchdog, in miliseconds.
+        The timeout of the watchdog, in miliseconds. Make this higher than the FreeRTOS tick rate.
 
 config TASK_WDT
     bool "Task watchdog"

components/esp32/brownout.c

@@ -23,15 +23,9 @@
 
 
 void esp_brownout_init() {
-//    WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 
-//            RTC_CNTL_BROWN_OUT_ENA | (CONFIG_BROWNOUT_DET_LVL << RTC_CNTL_DBROWN_OUT_THRES_S) |
-//            RTC_CNTL_BROWN_OUT_RST_ENA | (((CONFIG_BROWNOUT_DET_RESETDELAY*150)/1000) << RTC_CNTL_BROWN_OUT_RST_WAIT_S) |
-//            RTC_CNTL_BROWN_OUT_PD_RF_ENA|RTC_CNTL_BROWN_OUT_CLOSE_FLASH_ENA);
-
-
     WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 
-            RTC_CNTL_BROWN_OUT_ENA | (4 << RTC_CNTL_DBROWN_OUT_THRES_S) |
-            RTC_CNTL_BROWN_OUT_RST_ENA | (0x3FF << RTC_CNTL_BROWN_OUT_RST_WAIT_S) |
-            RTC_CNTL_BROWN_OUT_PD_RF_ENA | RTC_CNTL_BROWN_OUT_CLOSE_FLASH_ENA);
+            RTC_CNTL_BROWN_OUT_ENA | (CONFIG_BROWNOUT_DET_LVL << RTC_CNTL_DBROWN_OUT_THRES_S) |
+            RTC_CNTL_BROWN_OUT_RST_ENA | (((CONFIG_BROWNOUT_DET_RESETDELAY*150)/1000) << RTC_CNTL_BROWN_OUT_RST_WAIT_S) |
+            RTC_CNTL_BROWN_OUT_PD_RF_ENA|RTC_CNTL_BROWN_OUT_CLOSE_FLASH_ENA);
 
 }

components/esp32/cpu_start.c

@@ -44,6 +44,8 @@
 #include "esp_log.h"
 
 #include "esp_brownout.h"
+#include "esp_int_wdt.h"
+#include "esp_task_wdt.h"
 
 void start_cpu0(void) __attribute__((weak, alias("start_cpu0_default")));
 void start_cpu0_default(void) IRAM_ATTR;
@@ -143,10 +145,10 @@ void start_cpu0_default(void)
     esp_brownout_init();
 #endif
 #if CONFIG_INT_WDT
-    int_wdt_init()
+    int_wdt_init();
 #endif
 #if CONFIG_TASK_WDT
-    task_wdt_init()
+    task_wdt_init();
 #endif
 
     xTaskCreatePinnedToCore(&main_task, "main",

components/esp32/int_wdt.c

@@ -47,11 +47,6 @@ This uses the TIMERG1 WDT.
 
 #define WDT_WRITE_KEY 0x50D83AA1
 
-static void esp_int_wdt_isr(void *arg) {
-	abort();
-}
-
-
 void int_wdt_init() {
 	TIMERG1.wdt_wprotect=WDT_WRITE_KEY;
 	TIMERG1.wdt_config0.sys_reset_length=7;				//3.2uS
@@ -67,7 +62,9 @@ void int_wdt_init() {
 	TIMERG1.wdt_wprotect=0;
 	ESP_INTR_DISABLE(WDT_INT_NUM);
 	intr_matrix_set(xPortGetCoreID(), ETS_TG1_WDT_LEVEL_INTR_SOURCE, WDT_INT_NUM);
-	xt_set_interrupt_handler(WDT_INT_NUM, int_wdt_isr, NULL);
+	//We do not register a handler for the interrupt because it is interrupt level 4 which
+	//is not servicable from C. Instead, xtensa_vectors.S has a call to the panic handler for
+	//this interrupt.
 	ESP_INTR_ENABLE(WDT_INT_NUM);
 }
 

components/freertos/xtensa_vectors.S

@@ -339,12 +339,12 @@ _xt_panic:
     rsr     a0, EXCSAVE_1                   /* save interruptee's a0 */
     s32i    a0, sp, XT_STK_A0
 
-    /* Set up PS for C, reenable hi-pri interrupts, and clear EXCM. */
-    movi    a0, PS_INTLEVEL(XCHAL_EXCM_LEVEL) | PS_UM | PS_WOE
+    /* Set up PS for C, disable all interrupts, and clear EXCM. */
+    movi    a0, PS_INTLEVEL(7) | PS_UM | PS_WOE
     wsr     a0, PS
 
 	//Call panic handler
-	mov		a2,sp
+	mov		a6,sp
 	call4 panicHandler
 
 1:  j       1b                              /* loop infinitely */
@@ -1607,6 +1607,13 @@ _xt_highint4:
     ADD HIGH PRIORITY LEVEL 4 INTERRUPT HANDLER CODE HERE.
     */
 
+    /* On the ESP32, this level is used for the INT_WDT handler. If that triggers, the program is stuck with interrupts
+       off and the CPU should panic. */
+	rsr     a0, EXCSAVE_4
+	wsr     a0, EXCSAVE_1 /* panic handler reads this register */
+    call0 _xt_panic
+
+
     .align  4
 .L_xt_highint4_exit:
     rsr     a0, EXCSAVE_4                   /* restore a0 */