Merge branch 'bugfix/rtc_retain_mem_always_erased' into 'master'

Bootloader: retained memory can now be kept after reboot when custom data enabled

See merge request espressif/esp-idf!19809

components/bootloader/Kconfig.projbuild

@@ -403,7 +403,6 @@ menu "Bootloader config"
 
     config BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE
         hex "Size in bytes for custom purposes"
-        range 0 0x10
         default 0
         depends on BOOTLOADER_CUSTOM_RESERVE_RTC
         help

components/bootloader_support/.build-test-rules.yml

@@ -0,0 +1,7 @@
+# Documentation: .gitlab/ci/README.md#manifest-file-to-control-the-buildtest-apps
+
+components/bootloader_support/test_apps/rtc_custom_section:
+  disable:
+    - if: IDF_TARGET == "esp32c2"
+      temporary: false
+      reason: esp32c2 does not have RTC memory

components/bootloader_support/include/esp_image_format.h

@@ -53,8 +53,14 @@ typedef struct {
     uint32_t crc;                   /*!< Check sum crc32 */
 } rtc_retain_mem_t;
 
+
+_Static_assert(offsetof(rtc_retain_mem_t, crc) == sizeof(rtc_retain_mem_t) - sizeof(uint32_t), "CRC field must be the last field of rtc_retain_mem_t structure");
+
 #ifdef CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC
 _Static_assert(CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE % 4 == 0, "CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE must be a multiple of 4 bytes");
+/* The custom field must be the penultimate field */
+_Static_assert(offsetof(rtc_retain_mem_t, custom) == sizeof(rtc_retain_mem_t) - sizeof(uint32_t) - CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE,
+               "custom field in rtc_retain_mem_t structure must be the field before the CRC one");
 #endif
 
 #if defined(CONFIG_BOOTLOADER_SKIP_VALIDATE_IN_DEEP_SLEEP) || defined(CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC)

components/bootloader_support/src/bootloader_common_loader.c

@@ -116,6 +116,8 @@ int bootloader_common_select_otadata(const esp_ota_select_entry_t *two_otadata,
 
 #define RTC_RETAIN_MEM_ADDR (SOC_RTC_DRAM_HIGH - sizeof(rtc_retain_mem_t))
 
+_Static_assert(RTC_RETAIN_MEM_ADDR >= SOC_RTC_DRAM_LOW, "rtc_retain_mem_t structure size is bigger than the RTC memory size. Consider reducing RTC reserved memory size.");
+
 rtc_retain_mem_t *const rtc_retain_mem = (rtc_retain_mem_t *)RTC_RETAIN_MEM_ADDR;
 
 #ifndef BOOTLOADER_BUILD
@@ -128,14 +130,25 @@ rtc_retain_mem_t *const rtc_retain_mem = (rtc_retain_mem_t *)RTC_RETAIN_MEM_ADDR
 SOC_RESERVE_MEMORY_REGION(RTC_RETAIN_MEM_ADDR, RTC_RETAIN_MEM_ADDR + sizeof(rtc_retain_mem_t), rtc_retain_mem);
 #endif
 
+static uint32_t rtc_retain_mem_size(void) {
+#ifdef CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC
+    /* A custom memory has been reserved by the user, do not consider this memory into CRC calculation as it may change without
+     * the have the user updating the CRC. Return the offset of the custom field, which is equivalent to size of the structure
+     * minus the size of everything after (including) `custom` */
+    return offsetof(rtc_retain_mem_t, custom);
+#else
+    return sizeof(rtc_retain_mem_t) - sizeof(rtc_retain_mem->crc);
+#endif
+}
+
 static bool check_rtc_retain_mem(void)
 {
-    return esp_rom_crc32_le(UINT32_MAX, (uint8_t*)rtc_retain_mem, sizeof(rtc_retain_mem_t) - sizeof(rtc_retain_mem->crc)) == rtc_retain_mem->crc && rtc_retain_mem->crc != UINT32_MAX;
+    return esp_rom_crc32_le(UINT32_MAX, (uint8_t*)rtc_retain_mem, rtc_retain_mem_size()) == rtc_retain_mem->crc && rtc_retain_mem->crc != UINT32_MAX;
 }
 
 static void update_rtc_retain_mem_crc(void)
 {
-    rtc_retain_mem->crc = esp_rom_crc32_le(UINT32_MAX, (uint8_t*)rtc_retain_mem, sizeof(rtc_retain_mem_t) - sizeof(rtc_retain_mem->crc));
+    rtc_retain_mem->crc = esp_rom_crc32_le(UINT32_MAX, (uint8_t*)rtc_retain_mem, rtc_retain_mem_size());
 }
 
 void bootloader_common_reset_rtc_retain_mem(void)

components/bootloader_support/test_apps/rtc_custom_section/CMakeLists.txt

@@ -0,0 +1,6 @@
+# The following lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.16)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(test_rtc_custom_section)

components/bootloader_support/test_apps/rtc_custom_section/README.md

@@ -0,0 +1,2 @@
+| Supported Targets | ESP32 | ESP32-C3 | ESP32-S2 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- |

components/bootloader_support/test_apps/rtc_custom_section/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "test_main.c"
+                       INCLUDE_DIRS ".")

components/bootloader_support/test_apps/rtc_custom_section/main/test_main.c

@@ -0,0 +1,31 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "bootloader_common.h"
+#include <stdio.h>
+#include "sdkconfig.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define TEST_MAGIC_VALUE 0x42987561
+
+extern rtc_retain_mem_t* bootloader_common_get_rtc_retain_mem(void);
+
+void app_main(void) {
+    rtc_retain_mem_t* mem = bootloader_common_get_rtc_retain_mem();
+    uint32_t* _rtc_vars = (uint32_t*) mem->custom;
+
+    if (_rtc_vars[0] != TEST_MAGIC_VALUE) {
+        /* On the first boot, set the data inside the array */
+        _rtc_vars[0] = TEST_MAGIC_VALUE;
+    } else {
+        /* Second boot, the data was saved saved, success */
+        printf("SUCCESS: data were saved across reboot\n");
+        vTaskDelay(10000 / portTICK_PERIOD_MS);
+    }
+
+    esp_restart();
+}

components/bootloader_support/test_apps/rtc_custom_section/pytest_rtc_mem.py

@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: CC0-1.0
+
+import pytest
+from pytest_embedded import Dut
+
+
+@pytest.mark.generic
+@pytest.mark.esp32
+@pytest.mark.esp32c3
+@pytest.mark.esp32s2
+@pytest.mark.esp32s3
+def test_rtc_reserved_memory(dut: Dut) -> None:
+    dut.expect_exact('SUCCESS: data were saved across reboot', timeout=10)

components/bootloader_support/test_apps/rtc_custom_section/sdkconfig.defaults

@@ -0,0 +1,3 @@
+CONFIG_BOOTLOADER_RESERVE_RTC_SIZE=0x10
+CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC=y
+CONFIG_BOOTLOADER_CUSTOM_RESERVE_RTC_SIZE=0x200