feat(example): support deepsleep wakestub example for esp32s31

components/esp_rom/esp32s31/Kconfig.soc_caps.in

@@ -106,3 +106,7 @@ config ESP_ROM_CACHE_WRITEBACK_NEEDS_SYNC_TWICE_MAP
 config ESP_ROM_SUPPORT_SECURE_BOOT_FAST_WAKEUP
     bool
     default y
+
+config ESP_ROM_SUPPORT_DEEP_SLEEP_WAKEUP_STUB
+    bool
+    default y

components/esp_rom/esp32s31/esp_rom_caps.h

@@ -33,3 +33,4 @@
 #define ESP_ROM_BOOTLOADER_OFFSET_FLASH     (0x2000) // Bootloader offset in flash determined by the ROM bootloader
 #define ESP_ROM_CACHE_WRITEBACK_NEEDS_SYNC_TWICE_MAP (1) // ROM cache writeback related needs patch to avoid sync loss, need map parameter
 #define ESP_ROM_SUPPORT_SECURE_BOOT_FAST_WAKEUP (1) // ROM supports the secure boot fast wakeup feature
+#define ESP_ROM_SUPPORT_DEEP_SLEEP_WAKEUP_STUB  (1) // ROM supports the HP core to jump to the RTC memory to execute stub code after waking up from deepsleep.

components/esp_rom/esp32s31/include/esp32s31/rom/rtc.h

@@ -11,6 +11,7 @@
 extern "C" {
 #endif
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
 #include "esp_assert.h"
 
@@ -180,6 +181,37 @@ void software_reset(void);
   */
 void software_reset_cpu(int cpu_no);
 
+typedef void (* esp_rom_wake_func_t)(void);
+
+/**
+  * @brief Read stored RTC wake function address
+  *
+  * Returns pointer to wake address if a value is set in RTC registers, and stored length & CRC all valid.
+  * valid means that both stored stub length and stored wake function address are four-byte aligned non-zero values
+  * and the crc check passes
+  *
+  * @param  None
+  *
+  * @return esp_rom_wake_func_t : Returns pointer to wake address if a value is set in RTC registers
+  */
+esp_rom_wake_func_t esp_rom_get_rtc_wake_addr(void);
+
+/**
+  * @brief Store new RTC wake function address
+  *
+  * Set a new RTC wake address function. If a non-NULL function pointer is set then the function
+  * memory is calculated and stored also.
+  *
+  * @param entry_addr Address of function. should be 4-bytes aligned otherwise it will not start from the stub after wake from deepsleep，
+  *                   if NULL length will be ignored and all registers are cleared to 0.
+  *
+  * @param length length of function in RTC fast memory. should be less than RTC Fast memory size and aligned to 4-bytes.
+  *               otherwise all registers are cleared to 0.
+  *
+  * @return None
+  */
+void esp_rom_set_rtc_wake_addr(esp_rom_wake_func_t entry_addr, size_t length);
+
 /**
   * @}
   */

examples/system/deep_sleep_wake_stub/README.md

@@ -1,5 +1,5 @@
-| Supported Targets | ESP32 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-H2 | ESP32-H21 | ESP32-S2 | ESP32-S3 |
-| ----------------- | ----- | -------- | -------- | -------- | -------- | --------- | -------- | -------- |
+| Supported Targets | ESP32 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-H2 | ESP32-H21 | ESP32-S2 | ESP32-S3 | ESP32-S31 |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | --------- | -------- | -------- | --------- |
 
 # Deep Sleep Wake Stub Example