Reference: memfault-device-info
Useful links:
Purpose of memfault-device-info
memfault-device-info is a program that memfaultd depends on to retrieve
static information about the device it is running on. When memfaultd (or
memfaultctl) runs, it will execute memfault-device-info and parse the output
to collect this information.
As an integrator, you will need to implement this program and make it available
on the PATH of the memfaultd process. (By default on Yocto for systemd
units, this is /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin).
Implementing memfault-device-info
- When executed,
memfault-device-infoshould print out the device's unique identifier (for example, its serial number) and its hardware version in the following format:
MEMFAULT_DEVICE_ID=<device identifier>
MEMFAULT_HARDWARE_VERSION=<hardware version>
For example, an output might look like this:
MEMFAULT_DEVICE_ID=1234-example-serial
MEMFAULT_HARDWARE_VERSION=thingy-evt2
- The
MEMFAULT_DEVICE_IDvalue should be unique to the device. It should not change over the lifetime of the device. The value must be between 1 and 128 characters long and can only contain the following characters:a-z,A-Z,0-9,-and_. - The
MEMFAULT_HARDWARE_VERSIONvalue should be a string that identifies the hardware version of the device. It should not change over the lifetime of the device. See this page for more details and examples.
Optional Keys
From Linux SDK 1.8.0 on, memfault-device-info can also override the following
values that are set in memfaultd.conf:
- Software Version: can be set with
MEMFAULT_SOFTWARE_VERSION - Software Type: can be set with
MEMFAULT_SOFTWARE_TYPE
Testing
To test whether you have correctly implemented memfault-device-info, you can
run memfaultctl show-settings on the device. This will print out the device
info that memfaultctl has parsed and collected from memfault-device-info:
$ memfaultctl show-settings
...
Device configuration from memfault-device-info:
MEMFAULT_DEVICE_ID=1234-example-serial
MEMFAULT_HARDWARE_VERSION=thingy-evt2
...