HS HFS install on PCI SSD resulting in firmware error

[absente]

Hi,

I am having trouble getting High Sierra to install on a clean HFS formatted SM961 blade using PCI.

1. I created a bootable USB with the HS Installer
2. After booting from in, in terminal I execute
"/Volumes/Image Volume/Install macOS High Sierra.app/Contents/Resources/startosinstall" --volume /Volumes/SSD --converttoapfs NO
3. Resulting in error message " You may not install to this volume because the cimputer is missing a firmware partition"

My cMP is flashed from 4,1 to 5,1 using the 141.0.0.0.0 BootROM constructed by @tsialex

When running diskutil list I have the following info:

/dev/disk0 (external)
#: TYPE NAME SIZE IDENTIFIER
0: GUID 512,1GB disk0
1: EFI EFI 209.7MB disk0s1
2: Apple HFS SSD 511.8GB disk0s2

followed by by 20 disk images the installer is creating.

I tried everything, from reformatting, PRAM/SMC reset etc. I know some people managed to do a HS install on HFS formatted blades - what should I do ?

 

[tsialex]

When I need to install 10.13 with HFS+, I do it from macOS. I do the install to another empty disk. The message you are getting show that you have a non-standard install.

To accomplish what you want you have to start from a total vanilla install or startosinstall will not work correctly. Another thing: startosinstall with advanced options, converttoapfs is one, needs SIP to be disabled.

 

[cdf]

I've encountered this error many times when installing to my AHCI drive from within macOS. The drive icon is greyed-out in the installer. For some reason, the error goes away if the drive is seen as internal. You might want to try Innie when installing through macOS.