espressif/esp-idf
1
0
Fork 1
mirror of https://github.com/espressif/esp-idf.git synced 2025-08-05 05:34:32 +02:00
Code Issues Packages Projects Releases Wiki Activity

refactor (docs, rng): Clarify RNG usage

Browse Source
This commit is contained in:
Jakob Hasse
2022-04-06 16:45:43 +08:00
parent 77fcf15400
commit 3ceaba5b32
1 changed files with 10 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
components/bootloader_support/include/bootloader_random.h
View File

@@ -13,16 +13,21 @@ extern "C" {
#endif #endif
/** /**
* @brief Enable an entropy source for RNG if RF is disabled * @brief Enable an entropy source for RNG if RF subsystem is disabled
*
* @warning This function is not safe to use if any other subsystem is accessing the RF subsystem or
* the ADC at the same time!
* *
* The exact internal entropy source mechanism depends on the chip in use but * The exact internal entropy source mechanism depends on the chip in use but
* all SoCs use the SAR ADC to continuously mix random bits (an internal * all SoCs use the SAR ADC to continuously mix random bits (an internal
* noise reading) into the HWRNG. Consult the SoC Technical Reference * noise reading) into the HWRNG. Consult the SoC Technical Reference
* Manual for more information. * Manual for more information.
* *
* Can also be used from app code early during operation, if true * Can also be called from app code, if true random numbers are required without initialized RF subsystem.
* random numbers are required before RF is initialised. Consult * This might be the case in early startup code of the application when the RF subsystem has not
* ESP-IDF Programming Guide "Random Number Generation" section for * started yet or if the RF subsystem should not be enabled for power saving.
*
* Consult ESP-IDF Programming Guide "Random Number Generation" section for
* details. * details.
*/ */
void bootloader_random_enable(void); void bootloader_random_enable(void);
@@ -31,7 +36,7 @@ void bootloader_random_enable(void);
* @brief Disable entropy source for RNG * @brief Disable entropy source for RNG
* *
* Disables internal entropy source. Must be called after * Disables internal entropy source. Must be called after
* bootloader_random_enable() and before RF features, ADC, or * bootloader_random_enable() and before RF subsystem features, ADC, or
* I2S (ESP32 only) are initialized. * I2S (ESP32 only) are initialized.
* *
* Consult the ESP-IDF Programming Guide "Random Number Generation" * Consult the ESP-IDF Programming Guide "Random Number Generation"