sha256.h

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/*
 * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
#ifndef _HARDWARE_SHA256_H
#define _HARDWARE_SHA256_H
 
#include "pico.h"
#include "hardware/structs/sha256.h"

 
#ifdef __cplusplus
extern "C" {
#endif
 
// PICO_CONFIG: PARAM_ASSERTIONS_ENABLED_HARDWARE_SHA256, Enable/disable hardware_sha256 assertions, type=bool, default=0, group=hardware_sha256
#ifndef PARAM_ASSERTIONS_ENABLED_HARDWARE_SHA256
#ifdef PARAM_ASSERTIONS_ENABLED_SHA256 // backwards compatibility with SDK < 2.0.0
#define PARAM_ASSERTIONS_ENABLED_HARDWARE_SHA256 PARAM_ASSERTIONS_ENABLED_SHA256
#else
#define PARAM_ASSERTIONS_ENABLED_HARDWARE_SHA256 0
#endif
#endif

#define SHA256_RESULT_BYTES 32

enum sha256_endianness {
    SHA256_LITTLE_ENDIAN, 
    SHA256_BIG_ENDIAN,    
};

typedef union {
    uint32_t words[SHA256_RESULT_BYTES/4];
    uint8_t  bytes[SHA256_RESULT_BYTES];
} sha256_result_t;

static inline void sha256_set_dma_size(uint size_in_bytes) {
    uint32_t val;
    invalid_params_if(HARDWARE_SHA256, size_in_bytes != 1 && size_in_bytes != 2 && size_in_bytes != 4);
    if (size_in_bytes == 1) {
        val = SHA256_CSR_DMA_SIZE_VALUE_8BIT;
    } else if (size_in_bytes == 2) {
        val = SHA256_CSR_DMA_SIZE_VALUE_16BIT;
    } else {
        val = SHA256_CSR_DMA_SIZE_VALUE_32BIT;
    }
    hw_write_masked(&sha256_hw->csr, val << SHA256_CSR_DMA_SIZE_LSB, SHA256_CSR_DMA_SIZE_BITS);
}
 

static inline void sha256_set_bswap(bool swap) {
    if (swap) {
        hw_set_bits(&sha256_hw->csr, SHA256_CSR_BSWAP_BITS);
    } else {
        hw_clear_bits(&sha256_hw->csr, SHA256_CSR_BSWAP_BITS);
    }
}

static inline void sha256_start(void) {
    hw_set_bits(&sha256_hw->csr, SHA256_CSR_START_BITS);
}

static inline bool sha256_is_sum_valid(void) {
    return sha256_hw->csr & SHA256_CSR_SUM_VLD_BITS;
}

static inline bool sha256_is_ready(void) {
    return sha256_hw->csr & SHA256_CSR_WDATA_RDY_BITS;
}

static inline void sha256_wait_valid_blocking(void) {
    while (!sha256_is_sum_valid()) {
        tight_loop_contents();
    }
}

static inline void sha256_wait_ready_blocking(void) {
    while (!sha256_is_ready()) {
        tight_loop_contents();
    }
}

void sha256_get_result(sha256_result_t *out, enum sha256_endianness endianness);

static inline bool sha256_err_not_ready(void) {
    return sha256_hw->csr & SHA256_CSR_ERR_WDATA_NOT_RDY_BITS;
}

static inline void sha256_err_not_ready_clear(void) {
    hw_clear_bits(&sha256_hw->csr, SHA256_CSR_ERR_WDATA_NOT_RDY_BITS);
}

static inline volatile void *sha256_get_write_addr(void) {
    return &sha256_hw->wdata;
}

static inline void sha256_put_word(uint32_t word) {
    sha256_hw->wdata = word;
}

static inline void sha256_put_byte(uint8_t b) {
    *((io_rw_8*)&sha256_hw->wdata) = b;
}
 
#ifdef __cplusplus
}
#endif
 
#endif