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[[!tag open_issue_glibc open_issue_porting]]

There is a [[!FF_project 274]][[!tag bounty]] on this task.

There are now specialized variants of Debian's libc package, libc0.3-i686 and
libc0.3-xen.


On Thu, Oct 07, 2010 at 11:22:46AM +0200, Samuel Thibault wrote:
> Thomas Schwinge, le Thu 07 Oct 2010 10:11:07 +0200, a écrit :
> > Also, this text says ``will be selected instead when running under Xen''
> > -- is this meant to be automatically done?
>
> It's supposed to be, we need to add support for it.
>
> > If so, then it didn't work.
>
> Yes, you need to copy it by hand. Same for libc0.3-i686, we just need to
> steal the cpuid code from the kfreebsd port of glibc.


# IRC, freenode, #hurd, 2013-06-30

    <pinotree> other than that, the hwcap system is not working for us yet,
      right?
    <youpi> no but we'd like to use e.g. cpuid for that
    <youpi> like kfreebsd does
    <pinotree> do they use cpuid for that?
    <pinotree> i kind of lost myself in glibc's loading internals, trying to
      find out where the hwcap bits come from
    <youpi> on linux it comes from the kernel
    <youpi> on kfreebsd aiui they use cpuid to figure it out from the process
      itself
    <pinotree> do you have any pointer to the kfreebsd way? iirc i had a look
      in their sysdeps, but found nothing related to that
    <youpi> it's in local-sysdeps.diff aiui
    <youpi> +dl_platform_kfreebsd_i386_init
    <youpi> which fills dl_hwcap
    <youpi> called at _dl_sysdep_start
    <pinotree> interesting


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Having working CPUID code inside [[glibc]] is also a prerequisite for proper
[[IFUNC]] support.