On 04/22/2010 03:07 PM, Eric W. Biederman wrote: > > Have you tried loading a 64bit vmlinux directly into a higher address > range? There may be a bit or two missing but you should be able to > load a linux kernel above 4GB. I tested the basics of that mechanism > when I made the 64bit relocatable kernel. > > I don't buy the argument that there is a direct connection between > the amount of memory you have and how much memory it takes to dump it. > Even an indirect connections seems suspicious. > We actually have a 64-bit entry point even in bzImage; it is at offset +0x200 from the 32-bit entry point. Right now that offset is not exported anywhere, but it has been stable for a very long time... at least for as far back as the decompressor has been 64 bits. The interface to the 64-bit code is by necessity wider, since there is no such thing as paging off in 64-bit mode, but it probably isn't *too* hard to figure out how page tables need to be set up in order to work properly. At that point, it would be good to document it. -hpa
