5.28 NAND设备

学习阁2026/7/20大约 2 分钟设备驱动驱动NANDFlash坏块ECC

5.28 NAND设备

📚 本节导读

学习时长: 约 40 分钟
难度级别: ⭐⭐⭐⭐⭐
前置知识: C 语言基础、NAND Flash 基础知识、5.1 设备驱动框架、5.27 MTD 设备

🎯 学习目标

理解 NAND Flash 的页/块/区（Plane）三级寻址模型
掌握 os_nand_device 和 os_nand_ops 核心结构体
掌握坏块管理（Bad Block Management）的检测与标记
理解硬件 ECC 的配置与控制
掌握 Spare 区（OOB）的读写操作

一、概述

NAND 设备是 OneOS 提供的 NAND Flash 存储驱动框架，支持大容量 NAND Flash 芯片的页读写、块擦除、坏块管理、硬件 ECC 等功能。驱动源码位于 drivers/nand/ 目录下，核心头文件为 nand.h。

NAND 设备框架的特点：

三级寻址：页（Page）→ 块（Block）→ 区（Plane），支持大容量芯片
坏块管理：支持坏块检测（os_nand_badflag_check）和坏块标记（os_nand_badflag_mark）
硬件 ECC：支持硬件 ECC 的配置、使能和读取
Spare 区读写：支持 NAND 特有的 Spare 区（OOB）读写

二、核心数据结构

2.1 NAND 地址结构体

typedef struct {
    uint32_t page;  /* 页地址 */
    uint32_t plane; /* 区地址 */
    uint32_t block; /* 块地址 */
} os_nand_addr_t;

2.2 NAND 操作函数表 `struct os_nand_ops`

struct os_nand_ops
{
    os_err_t (*read_page)(os_nand_device_t *nand, uint32_t page_addr, uint8_t *buff, uint32_t page_nr);
    os_err_t (*write_page)(os_nand_device_t *nand, uint32_t page_addr, const uint8_t *buff, uint32_t page_nr);
    os_err_t (*read_spare)(os_nand_device_t *nand, uint32_t page_addr, uint8_t *buff, uint32_t spare_nr);
    os_err_t (*write_spare)(os_nand_device_t *nand, uint32_t page_addr, const uint8_t *buff, uint32_t spare_nr);
    os_err_t (*erase_block)(os_nand_device_t *nand, uint32_t page_addr);
    os_err_t (*config_hardecc)(os_nand_device_t *nand);
    os_err_t (*control_hardecc)(os_nand_device_t *nand, os_bool_t enable);
    os_err_t (*get_hardecc)(os_nand_device_t *nand, uint32_t *ecc_value);
    os_err_t (*get_status)(os_nand_device_t *nand);
};

2.3 NAND 设备结构体

struct os_nand_device
{
    struct os_device parent;
    struct os_nand_config cfg;
    const struct os_nand_ops *ops;
    uint8_t hardecc_flag;
    uint8_t *page_buff;
    uint8_t *spare_buff;
};

三、关键 API

3.1 注册与页操作

os_err_t os_nand_device_register(os_nand_device_t *nand, const char *name, uint32_t id);
os_err_t os_nand_read_page(os_nand_device_t *nand, uint32_t page_addr, uint8_t *buff, uint32_t page_nr);
os_err_t os_nand_write_page(os_nand_device_t *nand, uint32_t page_addr, const uint8_t *buff, uint32_t page_nr);
os_err_t os_nand_erase_block(os_nand_device_t *nand, uint32_t block_no);

3.2 坏块管理

os_err_t os_nand_badflag_check(os_nand_device_t *nand, uint32_t block_no);
os_err_t os_nand_badflag_mark(os_nand_device_t *nand, uint32_t block_no);

3.3 Spare 区与高级读写

os_err_t os_nand_read_spare(os_nand_device_t *nand, uint32_t page_addr, uint8_t *buff, uint32_t spare_nr);
os_err_t os_nand_write_spare(os_nand_device_t *nand, uint32_t page_addr, const uint8_t *buff, uint32_t spare_nr);
os_err_t os_nand_read(os_nand_device_t *nand, uint32_t page_addr, uint8_t *buff, uint32_t buff_len, uint8_t *oob, uint32_t oob_len);
os_err_t os_nand_write(os_nand_device_t *nand, uint32_t page_addr, const uint8_t *buff, uint32_t buff_len, const uint8_t *oob, uint32_t oob_len);

3.4 地址转换与芯片查询

void nand_page2addr(os_nand_device_t *nand, uint32_t page_addr, os_nand_addr_t *nand_addr);
uint32_t nand_addr2page(os_nand_device_t *nand, os_nand_addr_t *nand_addr);
const struct nand_device_info *get_nand_info_by_id(uint32_t id);

四、使用示例

#include <nand.h>

void nand_badblock_demo(void)
{
    os_device_t *dev = os_device_open("nand0");
    os_nand_device_t *nand = (os_nand_device_t *)dev;
    int block;

    for (block = 0; block < 1024; block++)
    {
        if (os_nand_badflag_check(nand, block) != OS_SUCCESS) continue;
        uint8_t buf[2048];
        os_nand_read_page(nand, block * 64, buf, 1);
        break;
    }
}

📝 本节小结

本节介绍了 NAND Flash 设备驱动，包括三级寻址、坏块管理、硬件 ECC、Spare 区读写等核心功能。