测试基于linux-2.6.27的9G9260开发板MTD驱动
1，修改内核源码：
root@yuanxh-desktop:/home/yuanxh/sam9260/linux-2.6.27-9g9260# vi arch/arm/mach-at91/board-sam9260ek.c
在第174行修改成如下：
/*
* NAND flash
*/
static struct mtd_partition __initdata ek_nand_partition[] = {
{
.name = "Bootstrap",
.offset = 0,
.size = 0x20000,
},
{
.name = "U-boot",
.offset = 0x20000,
.size = 0xe0000,
},
{
.name = "uImage",
.offset = 0x100000,
.size = 0x200000,
},
{
.name = "ramdisk",
.offset = 0x300000,
.size = 0x400000,
},
{
.name = "rootfs",
.offset = 0x700000,
.size = 0x900000,
},
{
.name = "data",
.offset = 16 * 1024 * 1024,
.size = MTDPART_SIZ_FULL,
},
};2，修改内核配置：
root@yuanxh-desktop:/home/yuanxh/sam9260/linux-2.6.27-9g9260# make menuconfig
Boot options --->
(mem=64M console=ttyS0,115200 root=/dev/mtdblock4 rootfstype=jffs2 init=/linuxrc)
Device Drivers --->
<*> Memory Technology Device (MTD) support --->
<*> MTD concatenating support
[*] MTD partitioning support
[*] Command line partition table parsing
<*> Direct char device access to MTD devices
-*- Common interface to block layer for MTD 'translation layers'
<*> Caching block device access to MTD devices
<*> NAND Device Support --->
<*> Support for NAND Flash / SmartMedia on AT91 and AVR32
ECC management for NAND Flash / SmartMedia on AT91 / AVR32 (Software ECC) --->
File systems --->
<*> Second extended fs support
Miscellaneous filesystems --->
<*> Journalling Flash File System v2 (JFFS2) support
(0) JFFS2 debugging verbosity (0 = quiet, 2 = noisy)
[*] JFFS2 write-buffering support
[*] JFFS2 summary support (EXPERIMENTAL)默认就是如此，不作修改。
3，编译内核：
root@yuanxh-desktop:/home/yuanxh/sam9260/linux-2.6.27-9g9260# make uImage
root@yuanxh-desktop:/home/yuanxh/sam9260/linux-2.6.27-9g9260# cp arch/arm/boot/uImage uImage-2.6.27-9g9260.bin
root@yuanxh-desktop:/home/yuanxh/sam9260/linux-2.6.27-9g9260# sz uImage-2.6.27-9g9260.bin
4，生成JFFS2文件系统：
root@yuanxh-desktop:/nfsboot# ./mkfs.jffs2 -d rootfs -o jffs2-2.6.27-9g9260.bin -n --pagesize=0x800 --eraseblock=0x20000 --pad=0x900000
root@yuanxh-desktop:/nfsboot# sz jffs2-2.6.27-9g9260.bin
5，测试MTD驱动
# cat /proc/mtd
# flash_eraseall /dev/mtd5
# mount -t jffs2 /dev/mtdblock5 /mnt
# cd /app
# touch yuanxihua
# vi yuanxhua
掉电后重新启动，看到文件及内容还存在。
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