esp_bootloader_format: Adds bootloader description structure to read bootloader version from app

Closes https://github.com/espressif/esp-idf/issues/8800
Closes https://github.com/espressif/esp-idf/issues/9132

components/esp_bootloader_format/esp_bootloader_desc.c

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <assert.h>
+#include <sys/param.h>
+#include "esp_bootloader_desc.h"
+#include "sdkconfig.h"
+
+
+// Bootloader version info
+const __attribute__((weak)) __attribute__((section(".data_bootloader_desc"))) esp_bootloader_desc_t esp_bootloader_desc = {
+    .magic_byte = ESP_BOOTLOADER_DESC_MAGIC_BYTE,
+    .reserved = { 0 },
+    .version = CONFIG_BOOTLOADER_PROJECT_VER,
+    .idf_ver = IDF_VER,
+#ifdef CONFIG_BOOTLOADER_COMPILE_TIME_DATE
+    .date_time = __DATE__ " " __TIME__,
+#else
+    .date_time = "",
+#endif
+    .reserved2 = { 0 },
+};
+
+_Static_assert(sizeof(IDF_VER) <= sizeof(esp_bootloader_desc.idf_ver), "IDF_VER is longer than idf_ver field in structure");
+
+const esp_bootloader_desc_t *esp_bootloader_get_description(void)
+{
+    return &esp_bootloader_desc;
+}