On Tue, Sep 14, 2021 at 03:49:31AM +0000, Yao, Jiewen wrote:
I can explain why we prefer DQ instead of DD.So a "save space in MEMFD" vs. "be future proof" tradeoff.
Back to 16 bit machine, we have entrypoint at F000:FFF0. But in 32bit mode we removed 1M limitation and move entrypoint to below 4G.Any plans to actually do that?
Defining an 64-bit entry point is a more than just using 64-bit
addresses. For starters long mode requires paging being enabled.
So a set of initial page tables is needed, and you possibly need
to handle virtual vs. physical addresses. You also need to find
a place above 4G where you can place the firmware without conflicts
with something else.
So I have my doubts that trying to make the struct future-proof
will actually work out in practice. Or that we will actually
need that anytime soon.