Generic x86_64 System
This is the base Nerves System configuration for a generic x86_64 system.
|Memory||512 MB+ DRAM|
|Storage||Hard disk/SSD/etc. (/dev/sda)|
|IEx terminal||Display - tty0|
Please contact us about this if you're really interested in it. We don't exercise it regularly except as a base for other x86_64 projects.
The most common way of using this Nerves System is create a project with
mix nerves.new and to export
MIX_TARGET=x86_64. See the Getting started
for more information.
If you need custom modifications to this system for your device, clone this repository and update as described in Making custom systems
Root disk naming
If you have multiple SSDs, or other devices connected, it's
possible that Linux will enumerate those devices in a nondeterministic order.
This can be mitigated by using
udev to populate the
directories, but even this can be inconvenient when you just want to refer to
the drive that provides the root filesystem. To address this,
/dev/rootdisk0p1, etc. and symlinks them to the expected
devices. For example, if your root file system is on
get a symlink from
/dev/mmcblk0p1 and the whole disk
/dev/rootdisk0. Similarly, if the root filesystem is on
you'd still get
/dev/rootdisk0 and they'd by symlinked
This system supports storing provisioning information in a small key-value store outside of any filesystem. Provisioning is an optional step and reasonable defaults are provided if this is missing.
Provisioning information can be queried using the Nerves.Runtime KV store's
Keys used by this system are:
||By default, this string is used to create unique hostnames and Erlang node names. If unset, it defaults to part of the Ethernet adapter's MAC address.|
The normal procedure would be to set these keys once in manufacturing or before deployment and then leave them alone.
For example, to provision a serial number on a running device, run the following and reboot:
iex> cmd("fw_setenv nerves_serial_number 12345678")
This system supports setting the serial number offline. To do this, set the
NERVES_SERIAL_NUMBER environment variable when burning the firmware. If you're
programming MicroSD cards using
fwup, the commandline is:
sudo NERVES_SERIAL_NUMBER=12345678 fwup path_to_firmware.fw
Serial numbers are stored on the MicroSD card so if the MicroSD card is replaced, the serial number will need to be reprogrammed. The numbers are stored in a U-boot environment block. This is a special region that is separate from the application partition so reformatting the application partition will not lose the serial number or any other data stored in this block.
Additional key value pairs can be provisioned by overriding the default provisioning.conf
file location by setting the environment variable
NERVES_PROVISIONING=/path/to/provisioning.conf. The default provisioning.conf
will set the
nerves_serial_number, if you override the location to this file,
you will be responsible for setting this yourself.