Die Datei wird wohl nicht gefunden, aber der Pfad ich richtig meiner Meinung nach
CFE> boot -tftp -elf 192.168.123.20:vmlinuz-rescue--3.4-r0.3-
dm820-20160405.bin
enter ui_cmd_bootcommon
arg 192.168.123.20:vmlinuz-rescue--3.4-r0.3-dm820-20160405.bin
loader elf filesys tftp
100 Mbps Full-Duplex
Device eth0: hwaddr 00-09-34-2F-3E-C4, ipaddr 192.168.123.20, mask 255.255.255.0
gateway 192.168.123.253, nameserver 192.168.123.253, domain fritz.box
Loader:elf Filesys:tftp Dev

null) File:192.168.123.20:vmlinuz-rescue--3.4-r0.3-
dm820-20160405.bin Options

null)
call cfe_boot()
Loading: Failed.
Could not load vmlinuz-rescue--3.4-r0.3-
dm820-20160405.bin: File not found
Trying again with '-nz' option
Loading: Failed.
Could not load vmlinuz-rescue--3.4-r0.3-
dm820-20160405.bin: File not found
leave ui_cmd_bootcommon
*** command status = -18