[ipxe-devel] "No iBFT detected" on Intel NUC

Michael Brown mcb30 at ipxe.org
Mon Sep 29 12:14:02 UTC 2014


On 28/09/14 14:54, Floris Bos wrote:
> It seems the iBFT gets placed too low in memory.
> The data MUST be located between 512K and 1024K according to the iBFT
> specification, for the OS to find it there.

Yes; this is a known problem.  When you use undionly.kpxe or 
undionly.kkpxe then the underlying PXE stack remains resident in base 
memory.  If this PXE stack is already occupying all of the memory from 
512kB upwards then there is no way for iPXE to place an iBFT in this 
location.

Check the segment addresses printed by pxeprefix.S when undionly.kkpxe 
first loads.  You will probably find that the relevant part of base 
memory is already occupied by the PXE base code.

You could try the following:

a) use undionly.kpxe instead of undionly.kkpxe; this will unload the PXE 
base code and so should free up more memory.

b) use an iPXE native driver (e.g. ipxe.pxe or intel.pxe); this will 
unload the whole underlying PXE stack.

Michael



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