Revised proposal to address Eric's comments. This is intended to provide full backwards compatibility while at the same time giving us the future flexibility. The intent will be to set by default: kernel_alignment = 16 MB min_alignment = log2(4K) or log2(2M) pref_address = 16 MB The reason to represent min_alignment as a logarithm is that I'm getting very concerned about the diminishing space that is left without a fundamental change to the initialized part of the header; specifically, right now we rely on the signed byte at offset 0x201 to contain the (additional) size of the header, which means end at 0x281 without a major format change of some sort. Comments appreciated. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.