mini2440 NorFlash驱动移植

 

编写Nor map驱动

-rwxr-xr-x   1 enzo enzo 253K  5月 18 16:32 u-boot.bin

Nor flash前256K存放uboot，所以驱动中定义的mtd_partition 要把uboot的空间留出来，不要破坏uboot

 

/*
 * mini2440 nor flash  mappings of chips in physical memory
 *
 */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>

#ifdef CONFIG_MTD_PARTITIONS
#include <linux/mtd/partitions.h>
#endif

#define WINDOW_ADDR 0x00000000 /* physical properties of flash */
#define WINDOW_SIZE 0x0200000 /*2M*/
#define BUSWIDTH    2 /*16bit bus*/
#define FLASH_BLOCKSIZE_MAIN    0x20000
#define FLASH_NUMBLOCKS_MAIN    128
/* can be "cfi_probe", "jedec_probe", "map_rom", NULL }; */
#define PROBETYPES { "cfi_probe","jedec_probe", "map_rom",NULL } /*mini2440 nor is jedec*/

#define MSG_PREFIX "Mini2440-NOR:" /* prefix for our printk()'s */
#define MTDID "Mini2440-nor" /* for mtdparts= partitioning */

static struct mtd_info *mymtd;

struct map_info mini2440nor_map = {
    .name = "NOR flash on mini2440",
    .size = WINDOW_SIZE,
    .bankwidth = BUSWIDTH,
    .phys = WINDOW_ADDR,
};

#ifdef CONFIG_MTD_PARTITIONS

/*
 * MTD partitioning stuff
 */
static struct mtd_partition static_partitions[] =
{
    {
        .name = "Bootloader",
        .size = 256*1024,
        .offset = 0
    },
    {
        .name = "reserve",
        .size = MTDPART_SIZ_FULL,
        .offset = MTDPART_OFS_APPEND
    },

};

static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };

#endif

static int mtd_parts_nb = 0;
static struct mtd_partition *mtd_parts = 0;

static int __init init_mini2440nor(void)
{
    static const char *rom_probe_types[] = PROBETYPES;
    const char **type;
    const char *part_type = 0;

    printk(KERN_NOTICE MSG_PREFIX "0x%08x at 0x%08xn",
           WINDOW_SIZE, WINDOW_ADDR);
    mini2440nor_map.virt = ioremap(WINDOW_ADDR, WINDOW_SIZE);

    if (!mini2440nor_map.virt) {
        printk(MSG_PREFIX "failed to ioremapn");
        return -EIO;
    }

    simple_map_init(&mini2440nor_map);

    mymtd = 0;
    type = rom_probe_types;
    for(; !mymtd && *type; type++) {
        mymtd = do_map_probe(*type, &mini2440nor_map);
    }
    if (mymtd) {
        mymtd->owner = THIS_MODULE;

#ifdef CONFIG_MTD_PARTITIONS
        mtd_parts_nb = parse_mtd_partitions(mymtd, probes, &mtd_parts, MTDID);
        if (mtd_parts_nb > 0)
            part_type = "detected";

        if (mtd_parts_nb == 0)
        {
            mtd_parts = static_partitions;
            mtd_parts_nb = ARRAY_SIZE(static_partitions);
            part_type = "static";
        }
#endif
        /* 注册设备 */
        add_mtd_device(mymtd);
        if (mtd_parts_nb == 0)
            printk(KERN_NOTICE MSG_PREFIX "no partition info availablen");
        else
        {
            printk(KERN_NOTICE MSG_PREFIX
             "using %s partition definitionn", part_type);
            add_mtd_partitions(mymtd, mtd_parts, mtd_parts_nb);
        }
        return 0;
    }

    iounmap((void *)mini2440nor_map.virt);
    return -ENXIO;
}

static void __exit cleanup_mini2440nor(void)
{
    if (mymtd) {
        del_mtd_device(mymtd);
        map_destroy(mymtd);
    }
    if (mini2440nor_map.virt) {
        iounmap((void *)mini2440nor_map.virt);
        mini2440nor_map.virt = 0;
    }
}

module_init(init_mini2440nor);
module_exit(cleanup_mini2440nor);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Enzo Fang ");
MODULE_DESCRIPTION("Generic configurable MTD map driver");

 

修改内核Makefile，Kconfig

 

修改/driver/mtd/maps/Makeconfig

obj-$(CONFIG_MTD_EDB7312)   += edb7312.o

obj-$(CONFIG_MTD_MINI2440) += mini2440flash.o

 

修改/drivers/mtd/maps/Kconfig

config MTD_EDB7312

    tristate "CFI Flash device mapped on EDB7312"

    depends on ARCH_EDB7312 && MTD_CFI

    help

      This enables access to the CFI Flash on the Cogent EDB7312 board.

      If you have such a board, say 'Y' here.

 

config MTD_MINI2440

    tristate "CFI Flash device mapped on MINI2440"

    depends on ARM && MTD_CFI

    help

      This enables access to the CFI Flash on the MINI2440 board.

      If you have such a board, say 'Y' here.

 

结果：

# cat /proc/mtd

dev:    size   erasesize  name

mtd0: 00200000 00001000 "NOR flash on mini2440"

mtd1: 00040000 00001000 "Bootloader"

mtd2: 001c0000 00001000 "reserve"

//todo 将nor加入平台驱动

 

格式化nor flash

//todo为文件系统添加mtd-utils

  [*] mtd-utils
  [*]   erase

  [*]   eraseall
  [*]   mkfs.jff2

擦除相应的存放jffs2文件系统的块

# eraseall /dev/mtd2

把该块以jffs2格式挂载到mnt下，这样在mnt目录下面就能执行任何写操作了。

# mount -t jffs2 /dev/mtdblock3 /mnt/

6.掉电重启，需要重新执行一遍mount -t jffs2 /dev/mtdblock3 /mnt/