STM32H7使用Serial V2框架配合DMA，可以修改DMA的buffer内存位置吗

发布于 2024-12-09 12:54:58 浏览：367 订阅该版

因为主内存设置在了dtcm，不能被dma访问，然而serial v2框架开启dma，缓存使用的是动态分配的内存，要如何修改buffer位置呢

3 个回答

KunYi 2024-12-10

这家伙很懒，什么也没写！

應該只能修改代碼與linkscript 去配置可以用DMA的記憶體區塊
參考 https://blog.csdn.net/whj123999/article/details/104402070

tjrong 2024-12-11

这家伙很懒，什么也没写！

当然是可以的，但是目前的驱动是动态分配的；如果要自己分配需要修改驱动代码。

宝宝A 2025-02-17

这家伙很懒，什么也没写！

参考实现

__attribute__((section(".ram_d2"))) uint8_t gps_rx_fifo[sizeof(struct rt_serial_rx_fifo) + BSP_UART3_RX_BUFSIZE];
    auto dev = rt_device_find("uart3");
    if (!dev) {
        log_w("uart3 not found");
        return;
    }
    auto serial_dev = reinterpret_cast<rt_serial_device *>(dev);
    rt_device_open(dev, RT_DEVICE_FLAG_RX_NON_BLOCKING | RT_DEVICE_FLAG_TX_BLOCKING);
    // replace fifo path as that cannot be dma
    dev->open_flag &= ~RT_SERIAL_RX_NON_BLOCKING;
    serial_dev->ops->control(serial_dev,
                             RT_DEVICE_CTRL_CLR_INT,
                             (void *) RT_SERIAL_RX_NON_BLOCKING);
    struct stm32_uart *uart = rt_container_of(serial_dev, struct stm32_uart, serial);
    HAL_UART_DMAStop(&(uart->handle));
    auto rx_fifo = (struct rt_serial_rx_fifo *) serial_dev->serial_rx;
    RT_ASSERT(rx_fifo != RT_NULL);
    rt_free(rx_fifo);
    rx_fifo = (struct rt_serial_rx_fifo *) gps_rx_fifo;
    rt_ringbuffer_init(&(rx_fifo->rb), rx_fifo->buffer, serial_dev->config.rx_bufsz);
    serial_dev->serial_rx = rx_fifo;
    dev->open_flag |= RT_SERIAL_RX_NON_BLOCKING;
    serial_dev->ops->control(serial_dev,
                             RT_DEVICE_CTRL_CONFIG,
                             (void *) RT_SERIAL_RX_NON_BLOCKING);