# 安装交叉编译工具链
sudo apt install gcc-arm-linux-gnueabihf

# 编译内核
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage

# 编译设备树
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- dtbs

// 字符设备驱动框架
static int dev_open(struct inode *inode, struct file *file) {
    printk(KERN_INFO "设备已打开
");
    return 0;
}

static ssize_t dev_read(struct file *file, char __user *buf, 
                        size_t count, loff_t *ppos) {
    copy_to_user(buf, kernel_data, count);
    return count;
}

static struct file_operations fops = {
    .owner = THIS_MODULE,
    .open = dev_open,
    .read = dev_read,
};

# Buildroot
git clone https://github.com/buildroot/buildroot
make menuconfig  # 配置
make             # 编译