Making World For amd64

[Tim Daneliuk]

Sean Cavanaugh wrote:
> 
> 
> --------------------------------------------------
> From: "Tim Daneliuk" <tundra at tundraware.com>
> Sent: Thursday, June 26, 2008 4:51 PM
> To: "Kris Kennaway" <kris at FreeBSD.org>; "FreeBSD Mailing List"
> <freebsd-questions at FreeBSD.org>
> Subject: Re: Making World For amd64
> 
>> Kris Kennaway wrote:
>>> Tim Daneliuk wrote:
>>>> Kris Kennaway wrote:
>>>>> Tim Daneliuk wrote:
>>>>>> Is there anything special one has to do when doing a make world
>>>>>> intended for 64-bit FreeBSD or is it sufficient to build the 64-bit
>>>>>> kernel and make world as everywhere else?
>>>>> The same as everywhere else.
>>>>>
>>>>> Kris
>>>>
>>>> So, I take it that this means that all the userspace programs, ports,
>>>> packages, utilities, etc. do *not* take advantage of the 64-bit
>>>> extensions.  That is, only the kernel gets the benefit of the
>>>> wider word.  Is that correct?
>>>>
>>>
>>> No, everything is 100% native.
>>>
>>> Kris
>>>
>>
>> OK, these may be really stupid questions but:
>>
>> 1) How does make world know whether to build 32-bit or 64-bit binaries?
>>
>> 2) Can a binary from a 32-bit FreeBSD system be run unmodified on the
>>  64-bit system?
>>
>> 3) If I reboot with 32-bit or 64-bit kernels, does the system magically
>>   somehow make the userland stuff work natively at the word width?
>>   If so, how?
>>
>> TIA,
> 
> 
> I take this to mean you have an i386 install and want to compile amd64
> on it.

No - although that is an interesting question in its own right.

I was more interested in the general question of whether 32-bit and
64-bit binaries are the same or different.  I would assume that something
has to be compiled to take advantage of 64-bit operations.  But this
then leads to the two questions: How does makeworld know which way to
build the binaries and Can a 32bit binary be run on a 64bit system (or
vice versa) in some compatibility or degraded mode...


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Tim Daneliuk     tundra at tundraware.com
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