* Ard Biesheuvel [off-list ref] wrote:
quoted
If we allocate the EFI runtime as a single virtual memory block then issues
like rounding between sections does not even come up as a problem: we map the
original offsets and sizes byte by byte.
Well, by that reasoning, we should not call SetVirtualAddressMap() in the first
place, and just use the 1:1 mapping UEFI uses natively. This is more than
feasible on arm64, and I actually fought hard against using
SetVirtualAddressMap() at all, but I was overruled by others. I think this is
also trivially possible on X64, since the 1:1 mapping is already active
alongside the VA mapping.
Could we please re-list all the arguments pro and contra of 1:1 physical mappings,
in a post that also explains the background so that more people can chime in, not
just people versed in EFI internals? It's very much possible that a bad decision
was made.
Thanks,
Ingo