From 8a656f006e8c22dfc047d1de7a6a27e17a78fb41 Mon Sep 17 00:00:00 2001
From: Konstantin Kondrashov <konstantin@espressif.com>
Date: Thu, 10 Jan 2019 20:17:04 +0800
Subject: [PATCH] esp32: Fix wdt settings in esp_restart_noos

Fixed compatibility the new apps with the old bootloaders.

Closes: https://github.com/espressif/esp-idf/issues/2927
---
 components/esp32/system_api.c        | 3 +--
 components/soc/esp32/rtc_wdt.c       | 5 +++++
 components/soc/include/soc/rtc_wdt.h | 9 +++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/components/esp32/system_api.c b/components/esp32/system_api.c
index 02993afa7d..d9b49183a3 100644
--- a/components/esp32/system_api.c
+++ b/components/esp32/system_api.c
@@ -279,8 +279,7 @@ void IRAM_ATTR esp_restart_noos()
     rtc_wdt_set_length_of_reset_signal(RTC_WDT_SYS_RESET_SIG, RTC_WDT_LENGTH_200ns);
     rtc_wdt_set_length_of_reset_signal(RTC_WDT_CPU_RESET_SIG, RTC_WDT_LENGTH_200ns);
     rtc_wdt_set_time(RTC_WDT_STAGE0, 1000);
-    rtc_wdt_enable();
-    rtc_wdt_protect_on();
+    rtc_wdt_flashboot_mode_enable();
 
     // Reset and stall the other CPU.
     // CPU must be reset before stalling, in case it was running a s32c1i
diff --git a/components/soc/esp32/rtc_wdt.c b/components/soc/esp32/rtc_wdt.c
index 67770709bc..1b01ce3046 100644
--- a/components/soc/esp32/rtc_wdt.c
+++ b/components/soc/esp32/rtc_wdt.c
@@ -38,6 +38,11 @@ void rtc_wdt_enable()
     SET_PERI_REG_MASK(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_EN | RTC_CNTL_WDT_PAUSE_IN_SLP);
 }
 
+void rtc_wdt_flashboot_mode_enable()
+{
+    REG_SET_BIT(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_FLASHBOOT_MOD_EN);
+}
+
 void rtc_wdt_disable()
 {
     bool protect = rtc_wdt_get_protect_status();
diff --git a/components/soc/include/soc/rtc_wdt.h b/components/soc/include/soc/rtc_wdt.h
index ec7175a002..bdaea942b4 100644
--- a/components/soc/include/soc/rtc_wdt.h
+++ b/components/soc/include/soc/rtc_wdt.h
@@ -118,6 +118,15 @@ void rtc_wdt_protect_off();
  */
 void rtc_wdt_enable();
 
+/**
+ * @brief Enable the flash boot protection procedure for WDT.
+ *
+ * Do not recommend to use it in the app.
+ * This function was added to be compatibility with the old bootloaders.
+ * This mode is disabled in bootloader or using rtc_wdt_disable() function.
+ */
+void rtc_wdt_flashboot_mode_enable();
+
 /**
  * @brief Disable rtc_wdt.
  */