Imagine High Sierra Without Firmware Update on JHFS+ Possible!

bsuggett
Contributor II

SNAP!... Title should start with Imaging not Imagine...

While we've only tested this with 2 different mac models, it appears to work. At least a temp solution until a proper solution to imaging large labs comes around.

Getting High Sierra imaged on a JHFS+ volume is possible for deployment with Casper Imaging.

At least on 1 machine the firmware update applies as your going through the installer. Machines imaged using Casper Imaging won't have the firmware applied. However test deploying this image on a machine without the firmware update has proved successful.

Performing the following has worked for us...Can't guarantee a 100% compatibility across all models...

  1. Start High Sierra install (if using startosinstall binary with the --converttoapfs NO, skip 1.a, 1.b and 1.c
    1.a. On first reboot, reboot to external or other device
    1.b. Open volume you started the install on, open /macOS Install Data/minstallconfig.xml
    1.c Modify
    <key>ConvertToAPFS</key>
    <true/>
    to
    <key>ConvertToAPFS</key>
    <false/>
    Save, Reboot / Resume the OS installation, Continue with the installation and customization's.

  2. Use Composer as you normally would to build your base DMG and deploy as you normally would as a JHFS+ volume.

This also suggest that the firmware pkg's found in /macOS Install Data/InstallESD.dmg are the firmware updates for booting to a APFS volume. Again can't confirm as trialing that has a potential to brick a mac.

5 REPLIES 5

alexjdale
Valued Contributor III

Yup, I used AutoDMG to successfully build and image with a 10.13.1 JHFS+ DMG yesterday. Still need to solve the firmware update issue, but it worked fine. Jamfhelper didn't work though, and the system sat at the login screen while the firstrun packages and scripts executed.

sebastianl
New Contributor III

HI bsuggett,

Sorry for my english, I don't quite get the first part you mentioned.

Start High Sierra install means run the run the high sierra installer or hit option key at startup?

For this part: "1.a. On first reboot, reboot to external or other device
1.b. Open volume you started the install on, open /macOS Install Data/minstallconfig.xml"

Care to elaborate more on how you do this? Sorry as I am still new to this and unsure how you access this.

Thank you!

reddrop
New Contributor III

Check out my Imaging of High Sierra workflow here.
It works with APFS and HFS
Deploying High Sierra 10.13 with Casper Imaging

bsuggett
Contributor II

@sebastianl

Answering your second question first... You can install almost any macOS to an external disk, so you can target boot. Use a bit of google fu on target booting to get the answers you seek. You can also choose to install High Sierra to an external drive first, then you will have something to target boot to later in mentioned steps 1.a and 1.b.

Assuming your currently running a previous OS say 10.12 aka Sierra. Start the High Sierra install by double clicking the "Install macOS High Sierra.app" within your applications directory. You'll be displayed a couple of question eg accepting EULA... where to install etc... Again assuming you have a default setup you'll choose to "Macintosh HD" without quotes to install to.

You should see a progress bar. Once this completes, your Mac should reboot. Immediately hold down the option/alt key until the boot meny/ boot picker displays. At this point you will need to target boot to an external disk you've created as I outlined above, so you can edit the xml on the disk you chose to install to (Macintosh HD). After which you restart, and resume the installation on which you first started the installation on.

jmahlman
Valued Contributor

@alexjdale So while it's at the login screen (where it says Temporary Adobe Install Account) it's running your first run in the background?~

~We're just getting around to testing 10.13.1 imaging and that seems to be my main hang-up is that it don't go to the jamf helper screen.

Seems to be the case...weird. Anyone contact jamf about this?