i want to share my experience in recover my bricked wrt54gl. As stupid as i was i tried to upgrade (downgrade) from kamikaze through xwrt2 with the result of a bricked router (blinking green light).
I spend most of the weekend trying different methods and finally i found a way to recover it.

1. power it down and open it up
2. ping 192.168.1.1 (from a terminal and let it run)
3. open your wrt54gl
4. shortcut pin 16 and 17.
5. put in the powercable and wait for ping respons. (If I rebooted my wrt54gl at this point i lost the ping.)

6 Connect directly through the internet and download  openwrt-wrt54g-squashfs.bin
7. Install linksys-tftp (check with your linuxdistro)
8. from a commandprompt run:
  a. linksys-tftp
  b. connect 192.168.1.1
  c. bin
  d. put openwrt-wrt54g-squashfs.bin root:admin
(now it will upload the file and "install" it without reboot. saying something like: uploaded 1.9 mb in 2.5 sec. if you dont write root:admin it will say something like: not connected "this i found out myself, creds to me")
  e. after about 2 min. the blinking will stop and you get a constant green light. wait a while and then end the session. (if i rebooted at this point i lossed the ping)

9. telnet 192.168.1.1
10. passwd xxxxx (change passwd)
11. ssh 192.168.1.1 -l root
12. wget http://downloads.openwrt.org/whiterussi … uashfs.trx (i didnt get a wan respons so i put another router between wan and the wrt54gl and then i put the wrt54gl's ip-adress to dmz on that router, then i could download the file).
13. mtd -e linux -r write openwrt-brcm-2.4-squashfs.trx linux (it installed normally and then the router rebooted.)

Now i had a fully working wrt54gl.