CPUTYPE?= in make.conf

[tech-lists]

Hello Dimitry,

On Fri, Oct 04, 2019 at 07:16:26PM +0200, Dimitry Andric wrote:

>This will never work.  Your host Sandybridge CPU is of an earlier
>generation (2nd) than the target, which is Haswell.
>
>Targeting Haswell, the compiler will generate instructions that the host
>CPU does not support, which in turn will lead to SIGILL signals as soon
>as such instructions are encountered.
>
>Similarly, btver1 is an AMD CPU (family 14h), which is likely to differ
>from your host CPU in which instructions it supports.  I guess you were
>just lucky that any programs ran at all... :)

ok, I can understand that, but

>This is not a hardware failure, but totally expected behavior.  You can
>only run poudriere builds for CPUs of an equal, or earlier generation,
>and even then you will have to ensure that the target CPU does not
>accidentally support instructions from your host CPU.

If I make a poudriere jail on the sandybridge host cpu (bought in 2013) with atom
n450 cpu (CPUTYPE?=bonnell specified in the jail's make.conf, 
target machine bought in 2010), nothing will build - when pkg tries to build,
get "illegal instruction" at the pkg phase.

I am going to try the same thing with the haswell host. 

thanks,
-- 
J.
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