CMG-NAM/CMG-NAM64 Platinum firmware recovery
- Recovery procedure
- Changing the root password
- Repairing a partial upgrade
- Other commands
This recovery procedure can be useful in two specific situations: if the root password has been forgotten, or if the firmware has become damaged by a partial upgrade (which is possible when upgrading from build 3801 or earlier due to a change in the C library version).
Physical access to the unit will be required.
- Standard PS/2 keyboard (QWERTY layout required)
- Standard VGA monitor
- Standard VGA cable
- For a multi-port NAM, a driver with a Torx TX8 bit
For a multi-port NAM, the case must be opened to gain access to the VGA and PS/2 connectors. This requires the four small Torx screws on the uppermost plate (towards the power supply end) to be removed.
Ensure the monitor and keyboard are plugged in. Reboot the system using either the reboot button or by removing and then restoring power. After a few seconds, there should be a screen with the message
GNU GRUB version 0.97 at the top, and a large box with one entry
Platinum inside. If the system boots too fast for this screen to show up, then reboot and repeatedly press the down arrow key
once a second until the screen is visible.
At this screen, press the key. Using the down arrow key () , scroll down to the second line which should look something like:
kernel /kernel root=/dev/md2
key once more. Type a space, and then type
rw init=/bin/bash followed by an enter key.
Now press the key and wait for the system to boot to a shell prompt (should only take a couple of seconds). If the system does not boot to a shell prompt (in particular if there are kernel panic messages or messages about being unable to mount a root filesystem) then the disk(s) will need to be returned to Güralp Systems for reflashing.
If the system has booted successfully, then a prompt similar to:
should be displayed.
It is generally not possible to recover the value of a lost password, as the value itself is not stored. However, it is possible to set a new one. Simply use the command:
To change the root password to a new value. Once this is done, you can use the reboot command and the system will behave normally, and you can use the freshly-set password to log in.
If an upgrade was only partially successful (e.g. release note instructions were not followed after a
FATAL: kernel too old message), it is possible to complete the process by running the commands:
touch /.magic_upgrade reboot
After the system has rebooted it should once again be functioning normally, although it may be sensible to run a further
upgrade just to be sure the filesystem is completely intact.
The above instructions provide for the most common recovery scenarios, but advanced users may be able to achieve other types of change or recovery using this special boot mode (single-user mode). The following commands may be helpful:
# bring up networking with DHCP dhcpcd eth0 # bring up networking with static IP ip link set up dev eth0 ip addr add 192.168.0.53/24 dev eth0 ip route add default via 192.168.0.254 echo 'nameserver 192.168.0.254' > /etc/resolv.conf