[ipxe-devel] Cannot boot to iPXE server with RealTek UEFI PXE boot after enabled the DMAr (IOMMU)

[Michael Brown]

On 27/12/2019 14:35, Angus.Ho at Dell.com wrote:
> Our Dell factory met one issue that the system cannot boot to iPXE 
> server with _UEFI PXE boot_ on Dell NPI platform (Intel CometLake-S) 
> *after BIOS enabled DMAr (IOMMU)*.
> <snip> 
> *The RealTek investigation result:*
> 
> For the 3.1 S/W UNDI Start command, the CPB structure shown below must 
> be filled in, but we found below function is NULL.
> 
> CpbPtr_31->Map_Mem

The screenshot shows that this is using an old version (commit 5430) of 
iPXE from 2016.  The issue that you are experiencing was fixed in 2018 
in commit

   http://git.ipxe.org/ipxe.git/commitdiff/e8e9ca361

You should find that the problem goes away if using an up to date 
version of iPXE.

Thanks,

Michael