bootloader: Refactoring

Need to make the bootloader modular so that users can redefine its functional part.

- refactoring and moving functions to the bootloader_support component
- Changed function to `void` bootloader_utility_load_image(...);

TW19596

components/bootloader_support/src/bootloader_common.c

@@ -0,0 +1,26 @@
+// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#include <stdbool.h>
+#include "rom/crc.h"
+#include "esp_flash_data_types.h"
+
+uint32_t bootloader_common_ota_select_crc(const esp_ota_select_entry_t *s)
+{
+    return crc32_le(UINT32_MAX, (uint8_t*)&s->ota_seq, 4);
+}
+
+bool bootloader_common_ota_select_valid(const esp_ota_select_entry_t *s)
+{
+    return s->ota_seq != UINT32_MAX && s->crc == bootloader_common_ota_select_crc(s);
+}