[LinuxBIOS] about make LinuxBIOS 64bit for Opteron

[Eric W. Biederman]

Ronald G Minnich <rminnich at lanl.gov> writes:

> Lu, Yinghai wrote:
>> I'm thinking to make LinuxBIOS to run at 64 bit mode so
>> it can access 40 bit address in one instruction
>> we just need to 1. change entry32.inc to entry64.inc...
>> 2. change secondary.S to support 64 bit
>> 3. change most code32 to code64
>> The problem is that we may need make Etherboot and mkelfImage to support
>> 64 bit too...
>> how do you think about it?
>> YH

Given the other objections and the fact that PAE mode allows
you to access any address you want by changing the page table.
I think we need a justification for doing more.

As for Etherboot and mkelfImage.  Etherboot can already load a 64bit
payload.  Basically just make the ELF loader capable of handling
a 32bit or a 64bit target.

Can you really put a page table in the cache and have it work?

Eric