feat(cmakev2/test): add fatfs_example and hello_world_example

Add two components: fatfs_example and hello_world_example. These are
simply copies of the main components from the existing examples.

Enhance the test_executable test to create targets for two
executables, which can be built after CMake configuration.

```
cmake --build build/ --target hello_world_example
cmake --build build/ --target fatfs_example
```

Additionally, move the test_component_priority to the end of the test
chain, as it modifies the esp_system component, which interferes with
the linkage of the executables.

Signed-off-by: Frantisek Hrbata <frantisek.hrbata@espressif.com>

tools/cmakev2/test/CMakeLists.txt

@@ -15,7 +15,6 @@ add_custom_target(flash)
 
 idf_project_init()
 
-
 # Test component priority
 function(test_component_priority)
     # Set the idf component to be replaced with a testing component of higher
@@ -205,14 +204,27 @@ function(test_include_component)
     endif()
 endfunction()
 
+# Add two executables fatfs_example and hello_world_example
+# After configuration these can be build with
+# cmake --build build/ --target hello_world_example
+# cmake --build build/ --target fatfs_example
 function(test_executable)
-    add_executable(test_executable components/component1/component1.c)
-    idf_build_library(INTERFACE test_executable_lib)
-    target_link_libraries(test_executable PRIVATE test_executable_lib)
+    idf_build_get_property(build_dir BUILD_DIR)
+    file(TOUCH "${build_dir}/test_executable.c")
+
+    add_executable(fatfs_example "${build_dir}/test_executable.c")
+    idf_build_library(INTERFACE fatfs_lib
+                      COMPONENTS fatfs_example)
+    target_link_libraries(fatfs_example PRIVATE fatfs_lib)
+
+    add_executable(hello_world_example "${build_dir}/test_executable.c")
+    idf_build_library(INTERFACE hello_world_lib
+                      COMPONENTS hello_world_example)
+    target_link_libraries(hello_world_example PRIVATE hello_world_lib)
+
 endfunction()
 
 # Run tests
-test_component_priority()
 test_idf_version()
 test_python()
 test_toolchain()
@@ -221,6 +233,10 @@ test_kconfig()
 test_project_properties()
 test_include_component()
 test_executable()
+
+# Call this test last because it replaces the ESP system component.
+test_component_priority()
+
 __dump_all_properties()
 __generate_project_info()
 

tools/cmakev2/test/components/fatfs_example/CMakeLists.txt

@@ -0,0 +1,3 @@
+idf_component_register(SRCS "fatfs_getting_started_main.c"
+                    PRIV_REQUIRES vfs fatfs lwip
+                    INCLUDE_DIRS ".")

tools/cmakev2/test/components/fatfs_example/fatfs_getting_started_main.c

@@ -0,0 +1,86 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "esp_vfs.h"
+#include "esp_vfs_fat.h"
+#include "sdkconfig.h"
+
+static const char *TAG = "example";
+
+// Mount path for the partition
+const char *base_path = "/spiflash";
+
+// Handle of the wear levelling library instance
+static wl_handle_t s_wl_handle = WL_INVALID_HANDLE;
+
+void app_main(void)
+{
+    ESP_LOGI(TAG, "Mounting FAT filesystem");
+    // To mount device we need name of device partition, define base_path
+    // and allow format partition in case if it is new one and was not formatted before
+    const esp_vfs_fat_mount_config_t mount_config = {
+        .max_files = 4, // Number of files that can be open at a time
+        .format_if_mount_failed = true, // If true, try to format the partition if mount fails
+        .allocation_unit_size = CONFIG_WL_SECTOR_SIZE, // Size of allocation unit, cluster size.
+        .use_one_fat = false, // Use only one FAT table (reduce memory usage), but decrease reliability of file system in case of power failure.
+    };
+
+    // Mount FATFS filesystem located on "storage" partition in read-write mode
+    esp_err_t err = esp_vfs_fat_spiflash_mount_rw_wl(base_path, "storage", &mount_config, &s_wl_handle);
+    if (err != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to mount FATFS (%s)", esp_err_to_name(err));
+        return;
+    }
+
+    ESP_LOGI(TAG, "Filesystem mounted");
+
+    ESP_LOGI(TAG, "Opening file");
+
+    const char *filename = "/spiflash/example.txt";
+
+    FILE *f = fopen(filename, "wb");
+    if (f == NULL) {
+        perror("fopen"); // Print reason why fopen failed
+        ESP_LOGE(TAG, "Failed to open file for writing");
+        return;
+    }
+
+    fprintf(f, "Hello World!\n");
+    fclose(f);
+
+    ESP_LOGI(TAG, "File written");
+
+    // Open file for reading
+    ESP_LOGI(TAG, "Reading file");
+
+    f = fopen(filename, "r");
+    if (f == NULL) {
+        ESP_LOGE(TAG, "Failed to open file for reading");
+        return;
+    }
+
+    char line[128];
+
+    fgets(line, sizeof(line), f);
+    fclose(f);
+
+    // strip newline
+    char *pos = strchr(line, '\n');
+    if (pos) {
+        *pos = '\0';
+    }
+
+    ESP_LOGI(TAG, "Read from file: '%s'", line);
+
+    // Unmount FATFS
+    ESP_LOGI(TAG, "Unmounting FAT filesystem");
+
+    ESP_ERROR_CHECK(esp_vfs_fat_spiflash_unmount_rw_wl(base_path, s_wl_handle));
+
+    ESP_LOGI(TAG, "Done");
+}

tools/cmakev2/test/components/hello_world_example/CMakeLists.txt

@@ -0,0 +1,3 @@
+idf_component_register(SRCS "hello_world_main.c"
+                       PRIV_REQUIRES spi_flash
+                       INCLUDE_DIRS "")

tools/cmakev2/test/components/hello_world_example/hello_world_main.c

@@ -0,0 +1,51 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <stdio.h>
+#include <inttypes.h>
+#include "sdkconfig.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_chip_info.h"
+#include "esp_flash.h"
+#include "esp_system.h"
+
+void app_main(void)
+{
+    printf("Hello world!\n");
+
+    /* Print chip information */
+    esp_chip_info_t chip_info;
+    uint32_t flash_size;
+    esp_chip_info(&chip_info);
+    printf("This is %s chip with %d CPU core(s), %s%s%s%s, ",
+           CONFIG_IDF_TARGET,
+           chip_info.cores,
+           (chip_info.features & CHIP_FEATURE_WIFI_BGN) ? "WiFi/" : "",
+           (chip_info.features & CHIP_FEATURE_BT) ? "BT" : "",
+           (chip_info.features & CHIP_FEATURE_BLE) ? "BLE" : "",
+           (chip_info.features & CHIP_FEATURE_IEEE802154) ? ", 802.15.4 (Zigbee/Thread)" : "");
+
+    unsigned major_rev = chip_info.revision / 100;
+    unsigned minor_rev = chip_info.revision % 100;
+    printf("silicon revision v%d.%d, ", major_rev, minor_rev);
+    if (esp_flash_get_size(NULL, &flash_size) != ESP_OK) {
+        printf("Get flash size failed");
+        return;
+    }
+
+    printf("%" PRIu32 "MB %s flash\n", flash_size / (uint32_t)(1024 * 1024),
+           (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "embedded" : "external");
+
+    printf("Minimum free heap size: %" PRIu32 " bytes\n", esp_get_minimum_free_heap_size());
+
+    for (int i = 10; i >= 0; i--) {
+        printf("Restarting in %d seconds...\n", i);
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+    }
+    printf("Restarting now.\n");
+    fflush(stdout);
+    esp_restart();
+}