Not so long ago HP published a customer advisory listing a number of their models that need to be on the latest BIOS release to be upgraded to Windows 10 2004. Since we were getting ready to rollout 20H2 we encountered some affected models in piloting, which prompted me to find that advisory and then get the BIOS updated on affected devices.
To be honest, until now we’ve never pushed out BIOS updates to anyone, but to get these devices updated to 20H2 we now had no choice. In this post I’m just going to share how we did that. For us, good user experience is critical but finding the balance between keeping devices secure and up-to-date without being too disruptive to the user can be a challenge!
First off was to create a script that could update the BIOS on any supported HP workstation, without needing to package and distribute BIOS update content. I know other equally handsome community members have shared some great scripts and solutions for doing BIOS updates, but I decided to create my own in this instance to meet our particular requirements and afford a bit more control over the update process. I considered using the HP Client Management Script Library which seems purpose-built for this kind of task and is a great resource, but I preferred not to have the dependency of an external PowerShell module and its requirements.
I published a version of this script in Github here. The script does the following:
- Creates a working directory under ProgramData
- Disables the IE first run wizard which causes a problem for the Invoke-WebRequest cmdlet when running in a context where IE hasn’t been initialised
- Checks the HP Image Assistant (HPIA) web page for the latest version and downloads it
- Extracts and runs the HPIA to identify the latest applicable BIOS update (if any)
- If a BIOS update is available, downloads and extracts the softpaq
- Checks if a BIOS password has been set, if so creates an encrypted password file as required by the firmware update utility
- Runs the firmware update utility to stage the update
- Everything is logged to the working directory and the logs are uploaded to Azure blob storage upon completion, or if something fails, so we can review them without requiring remote access to the user’s computer
It all runs silently without any user interaction and it can be run on any HP model that the HPIA supports.
In Production however, we used a slightly modified version of this script. Since there was the possibility that there could be unknown BIOS passwords in use out there, we decided not to try to flash the BIOS using an encrypted password file, but instead try to remove the BIOS password altogether (temporarily!) When the BIOS update is staged it simply copies the password file to the staging volume – it doesn’t check whether the password is correct or not. If it is not correct, the user would then be asked for the correct password when the BIOS is flashed and that is not cool! Removing the password meant that the user could never be unexpectedly prompted for the password in the event that the provided password file was incorrect. Of course, to remove the password you also have to know the password, so we tried the ones we knew and if they worked, great, if they didn’t, the script would simply exit out as a failsafe.
We have a compliance baseline deployed with MEMCM that sets the BIOS password on any managed workstation that does not have one set, so after the machine rebooted, the BIOS flashed and machine starts up again, before long the CB would run and set the password again.
Doing this also meant that we needed to ensure the computer was restarted asap after the update was staged – and for another reason as well – Bitlocker encryption is suspended until the update is applied and the machine restarted.
Because we didn’t want to force the update on users and force a restart on them, we decided to package the script as an application in MEMCM. This meant a couple of things:
- We could put a nice corporate logo on the app and make it available for install in the Software Center
- We could handle the return codes with custom actions. In this case, we are expecting the PowerShell script to exit successfully with code 0, and when it does we’ve set that code to be a soft reboot so that MEMCM restart notifications are then displayed to the user.
As a detection method, the following PowerShell code was used. This simply detects if the last write time of the log file has changed within the last hour, if it has, it’s installed. Longer than an hour and it’s available for install again if needed.
$Log = Get-ChildItem C:\ProgramData\Contoso\HP_BIOS_Update -Recurse -Include HP_BIOS_Update.log -ErrorAction SilentlyContinue |
where {([DateTime]::Now - $_.LastWriteTime).TotalHours -le 1}
If ($Log)
{
Write-Host "Installed"
}
We then deployed the application with an available deployment. We communicated with the users directly to inform them a BIOS update needed to be installed on their device in order to remain secure and up-to-date, and directed them to the Software Center to install it themselves.
We also prepared collections in SCCM using query-based membership rules to identify the machines that were affected by the HP advisory, and an SQL query to find the same information and pull the full user name and email address from inventoried data.
The script does contain the BIOS password in clear text which, or course, may not meet your security requirements, although for us this password is not really that critical – it’s just there to help prevent the user from making unauthorized changes in the BIOS. In our Production script though, we simply converted these to base64 before adding them to the script to at least provide some masking. But for greater security you could consider storing the password in Azure key vault and fetch it at run time with a web request, for example.
If you wish to use the script in your own environment, you’ll need to change the location of the working directory as you desire. Additionally if you wish to upload the log files to an Azure storage container, you’ll need to have or create a container and add the URL and the SAS token string to the script, or else just comment out the Upload-LogFilesToAzure function where it’s used. I’m a big fan of sending log files to Azure storage especially during this season where many are working from home and may not be corporate connected. You can just use Azure Storage Explorer to download the log files which will open up in CMTrace if that’s your default log viewer.
Hope this is helpful to someone! The PS script is below.
