mtd零星记录

查看Flash分区情况：

[email protected]-WRT:~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00020000 00010000 "RedBoot"
mtd1: 007c0000 00010000 "linux"
mtd2: 00270000 00010000 "rootfs"
mtd3: 00410000 00010000 "ddwrt"
mtd4: 00010000 00010000 "nvram"
mtd5: 00010000 00010000 "board_config"
mtd6: 00800000 00010000 "fullflash"
mtd7: 00020000 00010000 "fullboot"
[email protected]-WRT:~#

用dd备份分区（如果有fullash分区)

[email protected]-WRT:~# dd if=/dev/mtd6 of=/tmp/741_fullflash.bin
16384+0 records in
16384+0 records out
[email protected]-WRT:~#

刷成编程器固件命令(前提是有fullash分区)

[email protected]-WRT:~# mtd -r write fullflash /tmp/741_fullflash.bin
16384+0 records in
16384+0 records out
[email protected]-WRT:~#

编程openwrt固件时修改mach-tl-mr3x20.c(对应3420)增加一个fullash

}, {
  .name  = "fullflash",
  .offset  = 0,
  .size  = 0x800000,

  .mask_flags = MTD_WRITEABLE,

}

  .size  = 0x800000, 这个是flash大小8M

去掉  .mask_flags = MTD_WRITEABLE,是分区可以写，否者只可读

MTD subsystem has the following interfaces.

MTD character devices - usually referred to as /dev/mtd0, /dev/mtd1, and so on. These character devices provide I/O access to the raw flash. They support a number of ioctl calls for erasing eraseblocks, marking them as bad or checking if an eraseblock is bad, getting information about MTD devices, etc.
The sysfs interface is relatively newer and it provides full information about each MTD device in the system. This interface is easily extensible and developers are encouraged to use the sysfs interface instead of older ioctl or /proc/mtd interfaces, when possible. The sysfs interface for the mtd subsystem is documentated in the kernel, and currently can be found at Documentation/ABI/testing/sysfs-class-mtd.
The /proc/mtd proc file system file provides general MTD information. This is a legacy interface and the sysfs interface provides more information.