feat(soc): Added soc capabilities related to RNG for ESP32C5

components/bootloader_support/src/bootloader_random_esp32c5.c

@@ -9,6 +9,7 @@
 #include "hal/adc_ll.h"
 #include "hal/adc_types.h"
 #include "esp_private/regi2c_ctrl.h"
+#include "soc/lpperi_reg.h"
 
 #define I2C_SAR_ADC_INIT_CODE_VAL 2150
 
@@ -50,6 +51,9 @@ void bootloader_random_enable(void)
     adc_ll_digi_set_trigger_interval(200);
     adc_ll_digi_trigger_enable();
 
+    SET_PERI_REG_MASK(LPPERI_RNG_CFG_REG, LPPERI_RNG_SAMPLE_ENABLE);
+    REG_SET_FIELD(LPPERI_RNG_CFG_REG, LPPERI_RTC_TIMER_EN, 0x3);
+    SET_PERI_REG_MASK(LPPERI_RNG_CFG_REG, LPPERI_RNG_TIMER_EN);
 }
 
 void bootloader_random_disable(void)

components/esp_hw_support/hw_random.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2016-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2016-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -104,9 +104,18 @@ void esp_fill_random(void *buf, size_t len)
 }
 
 #if SOC_RNG_CLOCK_IS_INDEPENDENT && !ESP_TEE_BUILD
-ESP_SYSTEM_INIT_FN(init_rng_clock, SECONDARY, BIT(0), 102)
+ESP_SYSTEM_INIT_FN(init_rng, SECONDARY, BIT(0), 102)
 {
     _lp_clkrst_ll_enable_rng_clock(true);
+#if SOC_RNG_BUF_CHAIN_ENTROPY_SOURCE
+    SET_PERI_REG_MASK(LPPERI_RNG_CFG_REG, LPPERI_RNG_SAMPLE_ENABLE);
+#endif
+
+#if SOC_RNG_RTC_TIMER_ENTROPY_SOURCE
+    // This would only be effective if the RTC clock is enabled
+    REG_SET_FIELD(LPPERI_RNG_CFG_REG, LPPERI_RTC_TIMER_EN, 0x3);
+    SET_PERI_REG_MASK(LPPERI_RNG_CFG_REG, LPPERI_RNG_TIMER_EN);
+#endif
     return ESP_OK;
 }
 #endif

components/esp_system/system_init_fn.txt

@@ -72,8 +72,8 @@ SECONDARY: 100: esp_timer_init_os in components/esp_timer/src/esp_timer.c on ESP
 # HW stack guard via assist-debug module.
 SECONDARY: 101: esp_hw_stack_guard_init in components/esp_system/hw_stack_guard.c on ESP_SYSTEM_INIT_ALL_CORES
 
-# RNG module clock was disabled in `esp_perip_clk_init`, if hw_random is used, need to re-ebnabled it in startup
-SECONDARY: 102: init_rng_clock in components/esp_hw_support/hw_random.c on BIT(0)
+# Initialize RNG (enable clock which is disabled in `esp_perip_clk_init`, configure entropy sources)
+SECONDARY: 102: init_rng in components/esp_hw_support/hw_random.c on BIT(0)
 
 # Security specific initializations
 SECONDARY: 103: esp_security_init in components/esp_security/src/init.c on BIT(0)

components/soc/esp32c5/include/soc/Kconfig.soc_caps.in

@@ -1491,6 +1491,14 @@ config SOC_CRYPTO_DPA_PROTECTION_SUPPORTED
     bool
     default y
 
+config SOC_RNG_BUF_CHAIN_ENTROPY_SOURCE
+    bool
+    default y
+
+config SOC_RNG_RTC_TIMER_ENTROPY_SOURCE
+    bool
+    default y
+
 config SOC_UART_NUM
     int
     default 3
@@ -1703,6 +1711,10 @@ config SOC_MODEM_CLOCK_IS_INDEPENDENT
     bool
     default y
 
+config SOC_RNG_CLOCK_IS_INDEPENDENT
+    bool
+    default y
+
 config SOC_CLK_XTAL32K_SUPPORTED
     bool
     default y

components/soc/esp32c5/include/soc/soc_caps.h

@@ -585,6 +585,10 @@
 /*------------------------ Anti DPA (Security) CAPS --------------------------*/
 #define SOC_CRYPTO_DPA_PROTECTION_SUPPORTED     1
 
+/*-------------------------- RNG CAPS ---------------------------------------*/
+#define SOC_RNG_BUF_CHAIN_ENTROPY_SOURCE 1
+#define SOC_RNG_RTC_TIMER_ENTROPY_SOURCE 1
+
 /*-------------------------- UART CAPS ---------------------------------------*/
 // ESP32-C5 has 3 UARTs (2 HP UART, and 1 LP UART)
 #define SOC_UART_NUM                       (3)
@@ -669,6 +673,7 @@
 /*-------------------------- CLOCK SUBSYSTEM CAPS ----------------------------------------*/
 #define SOC_CLK_RC_FAST_SUPPORT_CALIBRATION       (1)
 #define SOC_MODEM_CLOCK_IS_INDEPENDENT            (1)
+#define SOC_RNG_CLOCK_IS_INDEPENDENT              (1)
 
 #define SOC_CLK_XTAL32K_SUPPORTED                 (1)     /*!< Support to connect an external low frequency crystal */
 #define SOC_CLK_OSC_SLOW_SUPPORTED                (1)     /*!< Support to connect an external oscillator, not a crystal */