esp-idf/components/bootloader_support/include_bootloader/bootloader_init.h

// 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.
#pragma once

#include "esp_err.h"
#include "esp_image_format.h"

/**@{*/
/**
 * @brief labels from bootloader linker script: bootloader.ld
 *
 */
extern int _bss_start;
extern int _bss_end;
extern int _data_start;
extern int _data_end;
/**@}*/

/**
 * @brief bootloader image header
 *
 */
extern esp_image_header_t bootloader_image_hdr;

/**@{*/
/**
 * @brief Common initialization steps that are applied to all targets.
 *
 */
esp_err_t bootloader_read_bootloader_header(void);
esp_err_t bootloader_check_bootloader_validity(void);
void bootloader_clear_bss_section(void);
void bootloader_config_wdt(void);
void bootloader_enable_random(void);
void bootloader_print_banner(void);
/**@}*/

/* @brief Prepares hardware for work.
 *
 * Setting up:
 * - Disable Cache access for both CPUs;
 * - Initialise cache mmu;
 * - Setting up pins and mode for SD, SPI, UART, Clocking.

 *  @return ESP_OK   - If the setting is successful.
 *          ESP_FAIL - If the setting is not successful.
 */
esp_err_t bootloader_init(void);