esp-idf/components/bootloader_support/src/esp32c2/bootloader_esp32c2.c

/*
 * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#include <stdint.h>
#include "sdkconfig.h"
#include "esp_attr.h"
#include "esp_log.h"
#include "esp_image_format.h"
#include "flash_qio_mode.h"
#include "esp_rom_gpio.h"
#include "esp_rom_efuse.h"
#include "esp_rom_uart.h"
#include "esp_rom_sys.h"
#include "esp_rom_spiflash.h"
#include "soc/efuse_reg.h"
#include "soc/gpio_sig_map.h"
#include "soc/io_mux_reg.h"
#include "soc/assist_debug_reg.h"
#include "esp_cpu.h"
#include "soc/rtc.h"
#include "soc/spi_periph.h"
#include "soc/extmem_reg.h"
#include "soc/io_mux_reg.h"
#include "soc/system_reg.h"
#include "esp32c2/rom/efuse.h"
#include "esp32c2/rom/ets_sys.h"
#include "esp32c2/rom/rtc.h"
#include "bootloader_common.h"
#include "bootloader_init.h"
#include "bootloader_clock.h"
#include "bootloader_flash_config.h"
#include "bootloader_mem.h"
#include "bootloader_console.h"
#include "bootloader_flash_priv.h"
#include "bootloader_soc.h"
#include "esp_private/bootloader_flash_internal.h"
#include "esp_efuse.h"
#include "hal/mmu_hal.h"
#include "hal/cache_hal.h"
#include "hal/rwdt_ll.h"

static const char *TAG = "boot.esp32c2";

static void wdt_reset_cpu0_info_enable(void)
{
    REG_SET_BIT(SYSTEM_CPU_PERI_CLK_EN_REG, SYSTEM_CLK_EN_ASSIST_DEBUG);
    REG_CLR_BIT(SYSTEM_CPU_PERI_RST_EN_REG, SYSTEM_RST_EN_ASSIST_DEBUG);
    REG_WRITE(ASSIST_DEBUG_CORE_0_RCD_EN_REG, ASSIST_DEBUG_CORE_0_RCD_PDEBUGEN | ASSIST_DEBUG_CORE_0_RCD_RECORDEN);
}

static void wdt_reset_info_dump(int cpu)
{
    (void) cpu;
    // saved PC was already printed by the ROM bootloader.
    // nothing to do here.
}

static void bootloader_check_wdt_reset(void)
{
    int wdt_rst = 0;
    soc_reset_reason_t rst_reason = esp_rom_get_reset_reason(0);
    if (rst_reason == RESET_REASON_CORE_RTC_WDT || rst_reason == RESET_REASON_CORE_MWDT0 ||
        rst_reason == RESET_REASON_CPU0_MWDT0 || rst_reason == RESET_REASON_CPU0_RTC_WDT) {
        ESP_LOGW(TAG, "PRO CPU has been reset by WDT.");
        wdt_rst = 1;
    }
    if (wdt_rst) {
        // if reset by WDT dump info from trace port
        wdt_reset_info_dump(0);
    }
    wdt_reset_cpu0_info_enable();
}

static void bootloader_super_wdt_auto_feed(void)
{
    REG_WRITE(RTC_CNTL_SWD_WPROTECT_REG, RTC_CNTL_SWD_WKEY_VALUE);
    REG_SET_BIT(RTC_CNTL_SWD_CONF_REG, RTC_CNTL_SWD_AUTO_FEED_EN);
    REG_WRITE(RTC_CNTL_SWD_WPROTECT_REG, 0);
}

static inline void bootloader_ana_reset_config(void)
{
    //Enable super WDT reset.
    bootloader_ana_super_wdt_reset_config(true);
    //Enable BOD reset
    bootloader_ana_bod_reset_config(true);
}

esp_err_t bootloader_init(void)
{
    esp_err_t ret = ESP_OK;

    bootloader_ana_reset_config();
    bootloader_super_wdt_auto_feed();

// In RAM_APP, memory will be initialized in `call_start_cpu0`
#if !CONFIG_APP_BUILD_TYPE_RAM
    // protect memory region
    bootloader_init_mem();
    /* check that static RAM is after the stack */
    assert(&_bss_start <= &_bss_end);
    assert(&_data_start <= &_data_end);
    // clear bss section
    bootloader_clear_bss_section();
#endif // !CONFIG_APP_BUILD_TYPE_RAM

    // init eFuse virtual mode (read eFuses to RAM)
#ifdef CONFIG_EFUSE_VIRTUAL
    ESP_LOGW(TAG, "eFuse virtual mode is enabled. If Secure boot or Flash encryption is enabled then it does not provide any security. FOR TESTING ONLY!");
#ifndef CONFIG_EFUSE_VIRTUAL_KEEP_IN_FLASH
    esp_efuse_init_virtual_mode_in_ram();
#endif
#endif
    // config clock
    bootloader_clock_configure();
    // initialize console, from now on, we can use esp_log
    bootloader_console_init();
    /* print 2nd bootloader banner */
    bootloader_print_banner();

#if !CONFIG_APP_BUILD_TYPE_RAM
    //init cache hal
    cache_hal_init();
    //init mmu
    mmu_hal_init();
    // update flash ID
    bootloader_flash_update_id();
    // read bootloader header
    if ((ret = bootloader_read_bootloader_header()) != ESP_OK) {
        return ret;
    }
    // read chip revision and check if it's compatible to bootloader
    if ((ret = bootloader_check_bootloader_validity()) != ESP_OK) {
        return ret;
    }
    // initialize spi flash
    if ((ret = bootloader_init_spi_flash()) != ESP_OK) {
        return ret;
    }
#endif // !CONFIG_APP_BUILD_TYPE_RAM

    // check whether a WDT reset happend
    bootloader_check_wdt_reset();
    // config WDT
    bootloader_config_wdt();
    // enable RNG early entropy source
    bootloader_enable_random();
    return ret;
}