Re: How to set x86 ISA needed property?

[Florian Weimer <fweimer@redhat.com>]

* Manuel Lauss via Libc-help:

> I've been building a userland for an AMD E-450 (gcc march=btver1) on
> a much more modern and faster x86 host.
> Now, the machione does not boot because up-to-date  glibc devel says this:
>
> /lib64/libc.so.6: CPU ISA level is lower than required
>
> readelf libc.so.6 says:
> Displaying notes found in: .note.gnu.property
>  Owner                Data size        Description
>  GNU                  0x00000010       NT_GNU_PROPERTY_TYPE_0
>      Properties: x86 ISA needed: x86-64-baseline, x86-64-v2, x86-64-v3
>
> x86-64-v3 is supported by the build machine, but the btver1 is at most -v2.
> This used to work in the past; is there a way to force glibc to a certain level?
> (binutils-2.35.1, gcc-10.2.1, glibc master as of 27.01.2021).

What does “gcc -v”?  What are you glibc configure/build flags?

This is expected to happen only if you use something like
-march=x86-64-v3 to build glibc, and only with recent toolchain
version.  I'm surprised you are hitting this with GCC 10, which does not
implement -march=x86-64-v3.

Thanks,
Florian
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