Debian on HP mv2120: important upgrade note

[Martin Michlmayr <tbm@cyrius.com>]

This is only relevant for people running Debian on the HP mv2120.

Mike Thompson reported that Debian stretch (the upcoming Debian 9)
doesn't boot on the HP mv2120 anymore.  I don't know how many Debian
users are left who run Debian on their mv2120.  I gave away my device
several years ago.  Recently I bought an mv2120 from eBay in order to
debug this issue.

While I found a solution, it requires users to change a setting on
their device.  Please make sure to make this change, otherwise your
device will no longer boot when you upgrade to Debian 9.

The new settings are compatible with Debian 8 (jessie) and Debian 9
(stretch), so I suggest you make the changes now.

If you have serial console access to the mv2120, you can run some
commands in u-boot.  Simply interrupt the boot process by pressing a
key and type the following:

    setenv loadAddr 0x0600000
    setenv bootcmd 'bootext2 0,1:1,2 0x0600000 /boot/uImage /dev/sda /dev/sdb'
    saveenv

If you don't have a serial console, you can make the changes from within
Debian.  Run the following commands:

    cat >/etc/fw_env.config <<EOF
    /dev/mtd0           0x00000         0x1000     0x20000
    EOF

    fw_setenv loadAddr 0x0600000
    fw_setenv bootcmd "bootext2 0,1:1,2 0x0600000 /boot/uImage /dev/sda /dev/sdb"

This creates a config file so the u-boot environment can be modified
and uses fw_setenv to update two boot variables.

Once you made the changes, upgrades to Debian 9 should work fine and
you can also use the Debian installer if you want to perform a new
installation.

Please note that Debian 9 will be the last release to support the HP
mv2120.

-- 
Martin Michlmayr
http://www.cyrius.com/