Merge branch 'feature/add_wakeup_cost_info_to_dslp_wakestub_example' …

…into 'master'

feature: add wake up time cost info to deep_sleep_wake_stub example

See merge request espressif/esp-idf!22683

components/esp_hw_support/sleep_modes.c

@@ -1652,7 +1652,13 @@ static uint32_t get_power_down_flags(void)
     return pd_flags;
 }
 
-void esp_deep_sleep_disable_rom_logging(void)
+#if CONFIG_IDF_TARGET_ESP32
+/* APP core of esp32 can't access to RTC FAST MEMORY, do not define it with RTC_IRAM_ATTR */
+void
+#else
+void RTC_IRAM_ATTR
+#endif
+esp_deep_sleep_disable_rom_logging(void)
 {
     rtc_suppress_rom_log();
 }

examples/system/deep_sleep_wake_stub/README.md

@@ -13,7 +13,7 @@ In this example, the `CONFIG_BOOTLOADER_SKIP_VALIDATE_IN_DEEP_SLEEP` Kconfig opt
 
 ### Hardware Required
 
-This example should be able to run on any commonly available ESP32/ESP32-S2/ESP32-S3/ESP32-C3 development board without any extra hardware if only **Timer** wake up sources are used.
+This example should be able to run on any commonly available ESP32/ESP32-S2/ESP32-S3/ESP32-C3/ESP32-C6 development board without any extra hardware if only **Timer** wake up sources are used.
 
 ### Configure the project
 
@@ -57,19 +57,28 @@ The ESP chips will then enter deep sleep. When a timer wake up occurs, if deep s
 
 ```
 ...
-ESP-ROM:esp32s3-20210327
-Build:Mar 27 2021
-rst:0x5 (DSLEEP),boot:0x8 (SPI_FAST_FLASH_BOOT)
-wake stub: wakeup count is 1, wakeup cause is 8
+ESP-ROM:esp32c6-20220919
+Build:Sep 19 2022
+rst:0x5 (SLEEP_WAKEUP),boot:0x2c (SPI_FAST_FLASH_BOOT)
+wake stub: wakeup count is 1, wakeup cause is 16, wakeup cost 6505 us
 wake stub: going to deep sleep
-ESP-ROM:esp32s3-20210327
-Build:Mar 27 2021
-rst:0x5 (DSLEEP),boot:0x8 (SPI_FAST_FLASH_BOOT)
-wake stub: wakeup count is 2, wakeup cause is 8
+ESP-ROM:esp32c6-20220919
+Build:Sep 19 2022
+rst:0x5 (SLEEP_WAKEUP),boot:0x2c (SPI_FAST_FLASH_BOOT)
+wake stub: wakeup count is 2, wakeup cause is 16, wakeup cost 6506 us
 wake stub: going to deep sleep
-ESP-ROM:esp32s3-20210327
-Build:Mar 27 2021
-rst:0x5 (DSLEEP),boot:0x8 (SPI_FAST_FLASH_BOOT)
-wake stub: wakeup count is 3, wakeup cause is 8
+ESP-ROM:esp32c6-20220919
+Build:Sep 19 2022
+rst:0x5 (SLEEP_WAKEUP),boot:0x2c (SPI_FAST_FLASH_BOOT)
+wake stub: wakeup count is 3, wakeup cause is 16, wakeup cost 6505 us
 wake stub: going to deep sleep
+
 ```
+
+> Note:
+
+> 1. The wakeup time cost printed in this example is not accurate, it does not take into account the hardware initialization time before the CPU starts, for most esp chips the initialization time cost is about 280us.
+
+> 2. And the wake-up time shown in this example is not the optimal wake-up time, because the ROM printing before the wake stub occupies most of the wake-up time, for most esp chips this ROM printing takes about 6100us. In the product firmware, users can temporarily or permanently turn off ROM printing via  call `esp_deep_sleep_disable_rom_logging` or set `menuconfig->Boot ROM Behavior->Permanently disable logging` to speed up the wake-up time.
+
+> 3. A method for roughly estimating optimal wake-up time: Taking esp32c6 as example, the wake-up time from stub printing is about 6500us, minus the ROM printing overhead of 6100us, plus the system initialization overhead of 280us, its optimal wake-up overhead is about 680us. Users also can modify the example to configure GPIO wake-up, and obtain a more realistic and accurate wake-up time by grabbing GPIO signals

examples/system/deep_sleep_wake_stub/main/rtc_wake_stub_example.c

@@ -6,6 +6,8 @@
 
 #include <inttypes.h>
 #include "esp_sleep.h"
+#include "esp_cpu.h"
+#include "esp_rom_sys.h"
 #include "esp_wake_stub.h"
 #include "sdkconfig.h"
 
@@ -33,15 +35,20 @@ static const uint32_t s_max_count = 20;
 // wakeup_cause stored in RTC memory
 static uint32_t wakeup_cause;
 
+// wakeup_time from CPU start to wake stub
+static uint32_t wakeup_time;
+
 // wake up stub function stored in RTC memory
 void wake_stub_example(void)
 {
+    // Get wakeup time.
+    wakeup_time = esp_cpu_get_cycle_count() / esp_rom_get_cpu_ticks_per_us();
     // Get wakeup cause.
     wakeup_cause = esp_wake_stub_get_wakeup_cause();
     // Increment the counter.
     s_count++;
     // Print the counter value and wakeup cause.
-    ESP_RTC_LOGI("wake stub: wakeup count is %d, wakeup cause is %d", s_count, wakeup_cause);
+    ESP_RTC_LOGI("wake stub: wakeup count is %d, wakeup cause is %d, wakeup cost %ld us", s_count, wakeup_cause, wakeup_time);
 
     if (s_count >= s_max_count) {
         // Reset s_count