1  // Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
  2  //
  3  // Licensed under the Apache License, Version 2.0 (the "License");
  4  // you may not use this file except in compliance with the License.
  5  // You may obtain a copy of the License at
  6  //
  7  //     http://www.apache.org/licenses/LICENSE-2.0
  8  //
  9  // Unless required by applicable law or agreed to in writing, software
 10  // distributed under the License is distributed on an "AS IS" BASIS,
 11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 12  // See the License for the specific language governing permissions and
 13  // limitations under the License.
 14  #include <string.h>
 15  #include <stdint.h>
 16  #include "sdkconfig.h"
 17  #include "esp_attr.h"
 18  #include "esp_log.h"
 19  #include "bootloader_init.h"
 20  #include "bootloader_flash_priv.h"
 21  #include "bootloader_flash_config.h"
 22  #include "bootloader_random.h"
 23  #include "bootloader_clock.h"
 24  #include "bootloader_common.h"
 25  #include "esp_flash_encrypt.h"
 26  #include "soc/cpu.h"
 27  #include "soc/rtc.h"
 28  #include "hal/wdt_hal.h"
 29  
 30  static const char *TAG = "boot";
 31  
 32  esp_image_header_t WORD_ALIGNED_ATTR bootloader_image_hdr;
 33  
 34  void bootloader_clear_bss_section(void)
 35  {
 36      memset(&_bss_start, 0, (&_bss_end - &_bss_start) * sizeof(_bss_start));
 37  }
 38  
 39  esp_err_t bootloader_read_bootloader_header(void)
 40  {
 41      /* load bootloader image header */
 42      if (bootloader_flash_read(ESP_BOOTLOADER_OFFSET, &bootloader_image_hdr, sizeof(esp_image_header_t), true) != ESP_OK) {
 43          ESP_LOGE(TAG, "failed to load bootloader image header!");
 44          return ESP_FAIL;
 45      }
 46      return ESP_OK;
 47  }
 48  
 49  esp_err_t bootloader_check_bootloader_validity(void)
 50  {
 51      /* read chip revision from efuse */
 52      uint8_t revision = bootloader_common_get_chip_revision();
 53      ESP_LOGI(TAG, "chip revision: %d", revision);
 54      /* compare with the one set in bootloader image header */
 55      if (bootloader_common_check_chip_validity(&bootloader_image_hdr, ESP_IMAGE_BOOTLOADER) != ESP_OK) {
 56          return ESP_FAIL;
 57      }
 58      return ESP_OK;
 59  }
 60  
 61  void bootloader_config_wdt(void)
 62  {
 63      /*
 64       * At this point, the flashboot protection of RWDT and MWDT0 will have been
 65       * automatically enabled. We can disable flashboot protection as it's not
 66       * needed anymore. If configured to do so, we also initialize the RWDT to
 67       * protect the remainder of the bootloader process.
 68       */
 69      //Disable RWDT flashboot protection.
 70      wdt_hal_context_t rtc_wdt_ctx = {.inst = WDT_RWDT, .rwdt_dev = &RTCCNTL};
 71      wdt_hal_write_protect_disable(&rtc_wdt_ctx);
 72      wdt_hal_set_flashboot_en(&rtc_wdt_ctx, false);
 73      wdt_hal_write_protect_enable(&rtc_wdt_ctx);
 74  
 75  #ifdef CONFIG_BOOTLOADER_WDT_ENABLE
 76      //Initialize and start RWDT to protect the  for bootloader if configured to do so
 77      ESP_LOGD(TAG, "Enabling RTCWDT(%d ms)", CONFIG_BOOTLOADER_WDT_TIME_MS);
 78      wdt_hal_init(&rtc_wdt_ctx, WDT_RWDT, 0, false);
 79      uint32_t stage_timeout_ticks = (uint32_t)((uint64_t)CONFIG_BOOTLOADER_WDT_TIME_MS * rtc_clk_slow_freq_get_hz() / 1000);
 80      wdt_hal_write_protect_disable(&rtc_wdt_ctx);
 81      wdt_hal_config_stage(&rtc_wdt_ctx, WDT_STAGE0, stage_timeout_ticks, WDT_STAGE_ACTION_RESET_RTC);
 82      wdt_hal_enable(&rtc_wdt_ctx);
 83      wdt_hal_write_protect_enable(&rtc_wdt_ctx);
 84  #endif
 85  
 86      //Disable MWDT0 flashboot protection. But only after we've enabled the RWDT first so that there's not gap in WDT protection.
 87      wdt_hal_context_t wdt_ctx = {.inst = WDT_MWDT0, .mwdt_dev = &TIMERG0};
 88      wdt_hal_write_protect_disable(&wdt_ctx);
 89      wdt_hal_set_flashboot_en(&wdt_ctx, false);
 90      wdt_hal_write_protect_enable(&wdt_ctx);
 91  }
 92  
 93  void bootloader_enable_random(void)
 94  {
 95      ESP_LOGI(TAG, "Enabling RNG early entropy source...");
 96      bootloader_random_enable();
 97  }
 98  
 99  void bootloader_print_banner(void)
100  {
101      ESP_LOGI(TAG, "ESP-IDF %s 2nd stage bootloader", IDF_VER);
102      ESP_LOGI(TAG, "compile time " __TIME__);
103  }