AxU3EG NVMe 裸机 例程

以下是使用AxU3EG NVMe裸机的简单例程：

1. 定义NVMe控制器寄存器地址。

#define NVME_CTRL_BASE_ADDR 0x10001000

2. 定义NVMe命名空间寄存器地址。

#define NVME_NS_BASE_ADDR 0x10002000

3. 定义NVMe命令和队列寄存器地址。

#define NVME_CMD_BASE_ADDR 0x10003000
#define NVME_Q_BASE_ADDR 0x10004000

4. 定义NVMe控制器结构体。

typedef struct {
    volatile uint32_t ctrl_reg_1;
    volatile uint32_t ctrl_reg_2;
    volatile uint32_t ctrl_reg_3;
    volatile uint32_t ctrl_reg_4;
    // ...
} nvme_ctrl_t;

5. 初始化NVMe控制器。

nvme_ctrl_t *nvme_ctrl = (nvme_ctrl_t *)NVME_CTRL_BASE_ADDR;

// 设置控制器寄存器
nvme_ctrl->ctrl_reg_1 = 0x12345678;
nvme_ctrl->ctrl_reg_2 = 0x87654321;
nvme_ctrl->ctrl_reg_3 = 0xdeadbeef;
nvme_ctrl->ctrl_reg_4 = 0xcafebabe;

// 初始化命令和队列
nvme_cmd_t *nvme_cmd = (nvme_cmd_t *)NVME_CMD_BASE_ADDR;
nvme_q_t *nvme_q = (nvme_q_t *)NVME_Q_BASE_ADDR;
nvme_ns_t *nvme_ns = (nvme_ns_t *)NVME_NS_BASE_ADDR;

6. 发送NVMe命令。

// 设置命令寄存器
nvme_cmd->command = NVME_CMD_READ;
nvme_cmd->lba = 0;
nvme_cmd->block_count = 1;
nvme_cmd->prp = (uint64_t)(buffer);

// 设置队列寄存器
nvme_q->sq_head = 0;
nvme_q->sq_tail = 1;
nvme_q->cq_head = 0;
nvme_q->cq_tail = 1;

// 等待完成
while (nvme_ctrl->ctrl_reg_1 & NVME_CTRL_BUSY);

// 检查状态
if (nvme_ctrl->ctrl_reg_2 & NVME_CTRL_ERROR) {
    printf("NVMe error: %08x\n", nvme_ctrl->ctrl_reg_3);
} else {
    printf("NVMe read successful!\n");
}

注：以上代码仅为示例，实际使用时需要根据具体硬件和驱动程序进行修改。