Comment 1 for bug 995758

Oh, and if I recall correctly, on the 80286 and 80386 and 80486, on reset the amount of addressable memory was 16MiB, 4GiB and 4GiB respectively, and IBM made the choice to map the BIOS ROMs to both the top of addressable memory and at the top of the first MiB. The CPU's themselves always reset to near the top of their address range, and the BIOS writers promptly jumped back down to somewhere near the top of the first MiB.