I successfully added ReBarDxe.ffs into my BIOS ROM file using UEFITool. However, when I try to flash the modified BIOS, the SM BMI rejects it with a security failure error.
I noticed that someone in the GitHub thread managed to apply this method successfully on the H11 board.
I would greatly appreciate any guidance or suggestions on how to overcome this security failure error and successfully enable ReBAR on my setup.
You can’t alter the BIOS on the H12 and later boards, it’s signed by SuperMicro and the SMI refuses to POST on an altered bios.
I had the same issue (Identical motherboard) and negotiated with SuperMicro to get a ReBAR enabled BIOS. They obliged and provided one with the feature, however enabling it prevents the system from posting for me.
Reportedly it works fine for them, perhaps reach out to them and ask if you can get a copy and test for them.
I saw your post on servethehome then. I contacted them and someone said they would get in touch with the bios team. Lets see what they can do this time.
While there is no officially signed contract/agreement, the fact that this is copyrighted, shared with a private URL, and password protected, and specified that it’s a “testing BIOS for test purpose only” it is very clear that they do not want this released to the general public by me.
Not only would I be in breach of their copyright by distributing this image, it would be disrespectful to SuperMicro and the staff member(s) that have been working to resolve this issue for free on a discontinued motherboard.
Usually custom changes to a BIOS outside of the specification in the manual require a contract with the manufacturer, for example:
You should be grateful they have tried.
Please note that I have not given up on this, I still need this feature myself. I am currently going through some major life changes that are taking the majority of my time which has caused many of my projects (including this) to take a back seat for now.
I had plans to dig into OpenBMC to try and make it work on the H12SSL-i. As well as modifying the BIOS. As far as I understand there are 3 pieces of firmware. The BIOS, BMC, and the CPLD/FPGA which handles the glue logic?
Supermicro doesn’t “vendor lock” the CPU through the PSB right? I wasn’t the one to fire up this motherboard for the first time so I don’t know if the screen asking to lock the CPU appears.
If only there was ReBarUEFI mod support for Z87 mobos and NvStrapsReBar support for Maxwell and older nvidia GPU’s. Would really be interesting to benchmark everything again
Yes, this is the new build I had. Still isn’t working for me but Supermicro have not been able to replicate the issue I have so it must be something external.
I can enable rebar in the BIOS but am unable to power any VMs under Vcenter with it enabled. Testing with Intel Arc A60 and RTX A4000. Pretty sure it’s a ESXI pass through issue I’m fighting now.
