Will vSPhere Hypervisor key will work on Vendor customized OEM ISO ESXi image ?

Hi

I tried downloading the vSphere Hypervisor 5.5 and 6.0 revs as ISOs and in booting both on my system neither would show HDDs in the systems.

The systems are HP DL380 Gen9 servers which I know are on the HCL.

Is it permissible to use a vendor customized OEM image with the vSphere Hypervisor (Free) key ?  Or is that not OK to do legally ?

In other words - must I take the vSphere Hypervisor ISO and Customize it by injecting the proper drivers into it so it will work to use the Free Key ?

Thanks

Big_Daddy68