Re: [patch 00/37] cpu/hotplug, x86: Reworked parallel CPU bringup

Thomas Gleixner
2023-04-19T13:43:26Z

On Wed, Apr 19 2023 at 14:38, Thomas Gleixner wrote:
> On Wed, Apr 19 2023 at 11:38, Thomas Gleixner wrote:
> IOW, the BIOS assignes random numbers to the AP APICs for whatever
> raisins, which leaves the parallel startup low level code up a creek
> without a paddle, except for actually reading the APICID back from the
> APIC. *SHUDDER*

So Andrew just pointed out on IRC that this might be related to the
ancient issue of the 3-wire APIC bus where IO/APIC and APIC shared the
ID space, but that system is definitely post 3-wire APIC :)

Thanks,

tglx