# compare_vpd

## Description
Compares a VPD (Vital Product Data) keyword value to an expected value.

VPD is information that describes a hardware component.  VPD is typically read
from an EEPROM on a Field-Replaceable Unit (FRU).  For this reason, VPD is also
called "FRU data".

The following VPD keywords are currently supported:
* CCIN
* Manufacturer
* Model
* PartNumber
* HW

This action can be used in an [if](if.md) condition to execute actions based on
a VPD keyword value.  For example, you could set the output voltage only for
regulators with a specific Model number.

## Properties
| Name | Required | Type | Description |
| :--- | :------: | :--- | :---------- |
| fru | yes | string | Field-Replaceable Unit (FRU) that contains the VPD.  Specify the relative D-Bus inventory path of the FRU.  Full inventory paths begin with the root "/xyz/openbmc_project/inventory".  Specify the relative path below the root, such as "system/chassis/disk_backplane". |
| keyword | yes | string | VPD keyword.  Specify one of the following: "CCIN", "Manufacturer", "Model", "PartNumber", "HW". |
| value | see [notes](#notes) | string | Expected value. |
| byte\_values | see [notes](#notes) | array of strings | One or more expected byte values expressed in hexadecimal.  Each value must be prefixed with 0x and surrounded by double quotes. |

### Notes
* You must specify either "value" or "byte_values".

## Return Value
Returns true if the keyword value equals the expected value, otherwise returns
false.

## Examples
```
{
  "comments": [ "Check if disk backplane has CCIN value 2D35" ],
  "compare_vpd": {
    "fru": "system/chassis/disk_backplane",
    "keyword": "CCIN",
    "value": "2D35"
  }
}
```
```
{
  "comments": [ "Check if disk backplane has CCIN value 0x32, 0x44, 0x33, 0x35" ],
  "compare_vpd": {
    "fru": "system/chassis/disk_backplane",
    "keyword": "CCIN",
    "byte_values": [ "0x32", "0x44", "0x33", "0x35" ]
  }
}
```