OVMS3-idf/components/bootloader_support/include/esp_efuse.h

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// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef _ESP_EFUSE_H
#define _ESP_EFUSE_H
#include "soc/efuse_reg.h"
#include "esp_err.h"
#ifdef __cplusplus
extern "C" {
#endif
/* @brief Permanently update values written to the efuse write registers
*
* After updating EFUSE_BLKx_WDATAx_REG registers with new values to
* write, call this function to permanently write them to efuse.
*
* @note Setting bits in efuse is permanent, they cannot be unset.
*
* @note Due to this restriction you don't need to copy values to
* Efuse write registers from the matching read registers, bits which
* are set in the read register but unset in the matching write
* register will be unchanged when new values are burned.
*
* @note This function is not threadsafe, if calling code updates
* efuse values from multiple tasks then this is caller's
* responsibility to serialise.
*
* After burning new efuses, the read registers are updated to match
* the new efuse values.
*/
void esp_efuse_burn_new_values(void);
/* @brief Reset efuse write registers
*
* Efuse write registers are written to zero, to negate
* any changes that have been staged here.
*/
void esp_efuse_reset(void);
/* @brief Disable BASIC ROM Console via efuse
*
* By default, if booting from flash fails the ESP32 will boot a
* BASIC console in ROM.
*
* Call this function (from bootloader or app) to permanently
* disable the console on this chip.
*/
void esp_efuse_disable_basic_rom_console(void);
/* @brief Encode one or more sets of 6 byte sequences into
* 8 bytes suitable for 3/4 Coding Scheme.
*
* This function is only useful if the CODING_SCHEME efuse
* is set to value 1 for 3/4 Coding Scheme.
*
* @param[in] in_bytes Pointer to a sequence of bytes to encode for 3/4 Coding Scheme. Must have length in_bytes_len. After being written to hardware, these bytes will read back as little-endian words.
* @param[out] out_words Pointer to array of words suitable for writing to efuse write registers. Array must contain 2 words (8 bytes) for every 6 bytes in in_bytes_len. Can be a pointer to efuse write registers.
* @param in_bytes_len. Length of array pointed to by in_bytes, in bytes. Must be a multiple of 6.
*
* @return ESP_ERR_INVALID_ARG if either pointer is null or in_bytes_len is not a multiple of 6. ESP_OK otherwise.
*/
esp_err_t esp_efuse_apply_34_encoding(const uint8_t *in_bytes, uint32_t *out_words, size_t in_bytes_len);
/* @brief Write random data to efuse key block write registers
*
* @note Caller is responsible for ensuring efuse
* block is empty and not write protected, before calling.
*
* @note Behaviour depends on coding scheme: a 256-bit key is
* generated and written for Coding Scheme "None", a 192-bit key
* is generated, extended to 256-bits by the Coding Scheme,
* and then writtten for 3/4 Coding Scheme.
*
* @note This function does not burn the new values, caller should
* call esp_efuse_burn_new_values() when ready to do this.
*
* @param blk_wdata0_reg Address of the first data write register
* in the block
*/
void esp_efuse_write_random_key(uint32_t blk_wdata0_reg);
#ifdef __cplusplus
}
#endif
#endif /* __ESP_EFUSE_H */