esp32 读写flash idf完整代码

以下是 ESP32 IDF 中读写 Flash 的完整代码示例：

#include <stdio.h>
#include "esp_log.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "esp_partition.h"

static const char* TAG = "flash-example";

#define SPI_DMA_CHAN    2

#define FLASH_SECTOR_SIZE 0x1000

#define SPI_FLASH_MOSI_PIN  23
#define SPI_FLASH_MISO_PIN  19
#define SPI_FLASH_CLK_PIN   18
#define SPI_FLASH_CS_PIN    5

// Function to initialize SPI bus
static void spi_init()
{
    // Define bus configuration
    spi_bus_config_t buscfg = {
        .miso_io_num = SPI_FLASH_MISO_PIN,
        .mosi_io_num = SPI_FLASH_MOSI_PIN,
        .sclk_io_num = SPI_FLASH_CLK_PIN,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
        .max_transfer_sz = 0
    };

    // Define device configuration
    spi_device_interface_config_t devcfg = {
        .clock_speed_hz = 10*1000*1000,      // Clock out at 10 MHz
        .mode = 0,                          // SPI mode 0
        .spics_io_num = SPI_FLASH_CS_PIN,    // CS pin
        .queue_size = 7,                    // We want to be able to queue 7 transactions at a time
        .pre_cb = NULL,                     // No pre-transfer callback
        .post_cb = NULL,                    // No post-transfer callback
        .flags = SPI_DEVICE_NO_DUMMY
    };

    // Initialize the SPI bus
    esp_err_t ret = spi_bus_initialize(VSPI_HOST, &buscfg, SPI_DMA_CHAN);
    ESP_ERROR_CHECK(ret);

    // Attach the flash chip to the SPI bus
    spi_device_handle_t spi_handle;
    ret = spi_bus_add_device(VSPI_HOST, &devcfg, &spi_handle);
    ESP_ERROR_CHECK(ret);
}

// Function to read from flash
static void read_flash()
{
    ESP_LOGI(TAG, "Reading flash...");

    // Open flash partition
    const esp_partition_t* partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_ANY, "my_partition");
    if (!partition) {
        ESP_LOGE(TAG, "Partition not found");
        return;
    }

    // Initialize SPI bus
    spi_init();

    // Set up transfer
    spi_transaction_t t = {
        .flags = SPI_TRANS_USE_RXDATA | SPI_TRANS_USE_TXDATA,
        .cmd = 0x03,    // Read command
        .addr = 0x0,    // Start address of read
        .length = 8*FLASH_SECTOR_SIZE // Read data size
    };

    // Read data from flash
    uint8_t* data = malloc(FLASH_SECTOR_SIZE);
    t.rx_buffer = data;
    for (int i = 0; i < partition->size; i += FLASH_SECTOR_SIZE) {
        t.addr = i;
        esp_err_t ret = spi_device_polling_transmit(spi_handle, &t);
        ESP_ERROR_CHECK(ret);
        ESP_LOGI(TAG, "Data at address 0x%x:", i);
        for (int j = 0; j < FLASH_SECTOR_SIZE; j++) {
            printf("%02x ", data[j]);
        }
        printf("\n");
    }

    // Clean up
    free(data);
    spi_bus_remove_device(spi_handle);
    spi_bus_free(VSPI_HOST);
}

// Function to write to flash
static void write_flash()
{
    ESP_LOGI(TAG, "Writing flash...");

    // Open flash partition
    const esp_partition_t* partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_ANY, "my_partition");
    if (!partition) {
        ESP_LOGE(TAG, "Partition not found");
        return;
    }

    // Initialize SPI bus
    spi_init();

    // Erase flash sector
    esp_err_t ret = spi_flash_erase_sector(partition->address);
    ESP_ERROR_CHECK(ret);

    // Set up transfer
    spi_transaction_t t = {
        .flags = SPI_TRANS_USE_RXDATA | SPI_TRANS_USE_TXDATA,
        .cmd = 0x02,    // Write command
        .addr = 0x0,    // Start address of write
        .length = 8*FLASH_SECTOR_SIZE // Write data size
    };

    // Write data to flash
    uint8_t* data = malloc(FLASH_SECTOR_SIZE);
    for (int i = 0; i < FLASH_SECTOR_SIZE; i++) {
        data[i] = i % 255;
    }
    t.tx_buffer = data;
    ret = spi_device_polling_transmit(spi_handle, &t);
    ESP_ERROR_CHECK(ret);

    // Clean up
    free(data);
    spi_bus_remove_device(spi_handle);
    spi_bus_free(VSPI_HOST);
}

void app_main()
{
    // Initialize NVS
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK(ret);

    // Write data to flash
    write_flash();

    // Read data from flash
    read_flash();
}

这个示例代码演示了如何使用 ESP32 的 SPI 总线来读写 Flash。其中，`spi_init()` 函数初始化了 SPI 总线，`read_flash()` 函数从 Flash 中读取数据，`write_flash()` 函数将数据写入 Flash。在这个示例代码中，我们使用了 SPI 总线连接的 Flash，但是也可以连接其他的 SPI 设备。同时，我们使用了 ESP-IDF 中提供的 `spi_device_polling_transmit()` 函数来进行数据的读写。如果你需要进行更高级的操作，可以使用 `spi_device_queue_trans()` 函数来设置队列，并使用回调函数来处理数据。