/* * SPDX-FileCopyrightText: 2017-2022 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #include "sdkconfig.h" #include "soc/soc.h" #include "soc/rtc.h" #include "hal/efuse_hal.h" #include "soc/rtc_cntl_reg.h" #if CONFIG_IDF_TARGET_ESP32 #include "hal/clk_tree_ll.h" #endif #include "esp_rom_sys.h" #include "esp_rom_uart.h" __attribute__((weak)) void bootloader_clock_configure(void) { // ROM bootloader may have put a lot of text into UART0 FIFO. // Wait for it to be printed. // This is not needed on power on reset, when ROM bootloader is running at // 40 MHz. But in case of TG WDT reset, CPU may still be running at >80 MHZ, // and will be done with the bootloader much earlier than UART FIFO is empty. esp_rom_uart_tx_wait_idle(0); /* Set CPU to 80MHz. Keep other clocks unmodified. */ int cpu_freq_mhz = 80; #if CONFIG_IDF_TARGET_ESP32 /* On ESP32 rev 0, switching to 80/160 MHz if clock was previously set to * 240 MHz may cause the chip to lock up (see section 3.5 of the errata * document). For rev. 0, switch to 240 instead if it has been enabled * previously. */ if (efuse_hal_get_major_chip_version() == 0 && clk_ll_cpu_get_freq_mhz_from_pll() == CLK_LL_PLL_240M_FREQ_MHZ) { cpu_freq_mhz = 240; } #elif CONFIG_IDF_TARGET_ESP32H2 cpu_freq_mhz = 64; #endif if (esp_rom_get_reset_reason(0) != RESET_REASON_CPU0_SW || rtc_clk_apb_freq_get() < APB_CLK_FREQ) { rtc_clk_config_t clk_cfg = RTC_CLK_CONFIG_DEFAULT(); clk_cfg.cpu_freq_mhz = cpu_freq_mhz; clk_cfg.slow_clk_src = rtc_clk_slow_src_get(); if (clk_cfg.slow_clk_src == SOC_RTC_SLOW_CLK_SRC_INVALID) { clk_cfg.slow_clk_src = SOC_RTC_SLOW_CLK_SRC_RC_SLOW; } clk_cfg.fast_clk_src = rtc_clk_fast_src_get(); if (clk_cfg.fast_clk_src == SOC_RTC_FAST_CLK_SRC_INVALID) { clk_cfg.fast_clk_src = SOC_RTC_FAST_CLK_SRC_XTAL_DIV; } rtc_clk_init(clk_cfg); } /* As a slight optimization, if 32k XTAL was enabled in sdkconfig, we enable * it here. Usually it needs some time to start up, so we amortize at least * part of the start up time by enabling 32k XTAL early. * App startup code will wait until the oscillator has started up. */ #if CONFIG_ESP_SYSTEM_RTC_EXT_XTAL if (!rtc_clk_32k_enabled()) { rtc_clk_32k_bootstrap(CONFIG_ESP_SYSTEM_RTC_EXT_XTAL_BOOTSTRAP_CYCLES); } #endif // CONFIG_ESP_SYSTEM_RTC_EXT_XTAL REG_WRITE(RTC_CNTL_INT_ENA_REG, 0); REG_WRITE(RTC_CNTL_INT_CLR_REG, UINT32_MAX); }