vpd

Reads the information from VPD.

Function Arguments

Name	Type	Description
fields	list, None	(optional; default: None) A list of fields of VPD data to probe.
key	str, None	(optional; default: None) The key of the result. Can be specified only if the fields argument contains exact one element
partition	[‘ro’, ‘rw’]	(optional; default: 'ro') The partition name to read, can be either “ro” or “rw”

Description

This function probes the VPD data in the firmware by calling the command vpd.

This function supplies 3 modes:

1. If the user doesn’t specify any field name of VPD data to probe (i.e. both the arguments field and key are None), the probed result will be a dict contains all fields in the VPD data.

2. If the user specifies a list of fields (ex: fields=['a', 'b', ...]), the probed result will contain only specified fields. The user also can specify the argument key='another_key_name' to customize the key name in the result dict if the specified fields contains only element.

Examples

Let’s assume that the read-only VPD partition contains these fields:

serial=12345
region=us

And read-write VPD partition contains:

k1=v1
k2=v2
k3=v3

And we have the probe config file:

{
  "all_ro_vpd_data": {  # Simplest example, just dump all fields in RO VPD.
    "from_firmware": {
      "eval": "vpd"
    }
  },

  "region": {
    "from_firmware": {
      "eval": {
        "vpd": {
          "fields": [
            "region"
          ],
          "key": "region_code"  # In this case we rename the key from
                                # "region" to "region_code".
        }
      }
    }
  },

  "k1k2_rw_vpd_data": {  # In this case we only output k1, k2 from the RW
                         # VPD.
    "from_firmware": {
      "eval": {
        "vpd": {
          "partition": "rw",
          "fields": [
            "k1",
            "k2"
          ]
        }
      }
    }
  }
}

Then the corresponding output will be:

{
  "all_ro_vpd_data": [
    {
      "name": "from_firmware",
      "values": {
        "serial": "12345",
        "region": "us"
      }
    }
  ],

  "region": [
    {
      "name": "from_firmware",
      "values": {
        "region_code": "us"
      }
    }
  ],

  "k1k2_rw_vpd_data": [
    {
      "name": "from_firmware",
      "values": {
        "k1": "v1",
        "k2": "v2"
      }
    }
  ]
}