my router is linksys WRT54GL with backfire os. i already try reset with "firstboot" and "mtd -r erase rootfs_data" , after reboot i still can't access it with static ip address or dhcp. sorry for my bad english, Please help
finally i can solve my problem with flashing router and clean the nvram. i use openwrt brcm24 http://downloads.openwrt.org/whiterussian/newest/default/openwrt-brcm-2.4-squashfs.trx and flash with this script http://downloads.openwrt.org/people/nbd/nvram-clean.sh.
use mtd -r write openwrt-brcm-2.4-squashfs.trx linux to flash ,reboot then
./nvram-clean.sh and nvram commit to clean nvram
more info : https://wiki.openwrt.org/doc/howto/generic.failsafe