The solution to this problem has already been discussed here. You just need to replace in the file devicetree.cb "lapic 4" to "lapic 0xbeef".
*device cpu_cluster 0 on #device lapic 4 on end device lapic 0xbeef on end #NOTE: correct Local APIC ID is set in in dev_enumerate() end* This works for two cores (C3338), quad cores (C3538), eight cores, twelve cores, and 16 cores - I've tested this. пн, 16 авг. 2021 г. в 19:45, Jay Talbott <[email protected]>: > Unfortunately, for the Denverton SoC (C3000 series), the APIC ID of the > first core is not always the same. For 16-core SKUs, it’s always 0, but for > SKUs with a lower number of cores, it may be a different number. It’s also > possible (but not confirmed) that for a particular SKU (other than 16-core > SKUs), it might not be consistent between parts. The solution is to > basically ignore the value in devicetree and use the actual APIC ID from > the first core. > > > > - Jay > > > > *From:* Sumo [mailto:[email protected]] > *Sent:* Monday, August 16, 2021 9:15 AM > *To:* Nico Huber > *Cc:* Дмитрий Понаморев; Coreboot > *Subject:* [coreboot] Re: A different lapic number in devicetree.cb > needed for CPU with the same SKU and steping (Intel Atom C3538). > > > > Hi, > > > > > have you tried omitting the `device lapic` line from the devicetree? > > I have tested this, in this case Linux shows only one processor core. > Therefore the 'device lapic' line is really needed... > > > > I can submit that Local APIC Fixup patch to gerrit but I'm not sure if > this is really the best solution. > > > > Kind regards, > > Sumo > > > > > > On Wed, Oct 7, 2020 at 6:35 PM Nico Huber <[email protected]> wrote: > > Hi, > > have you tried omitting the `device lapic` line from the devicetree? > It would only matter if there is configuration associated with it, but > I can't see anything like that for `intel/harcuvar`. > > What happens is that this `device lapic` line in the devicetree becomes > an entry in a list at runtime. This list is later filled with the actual > cores present. If any of the actual cores has the same APIC id as given > in the devicetree, no additional entry is added for this core. However > if none of the actual cores has that id, the original entry is left > blindly in the list, causing coreboot to report the spurious, fifth > core. > > On 07.10.20 21:27, [email protected] wrote: > > Thank you so much Javier Galindo! > > > > Sorry for not finding this case myself ... > > I checked it on the motherboard with lapic #4 - everything works as it > should. > > Tomorrow I'll check it on the motherboard with lapic #0. > > I wish I could understand how this magic works :)! lapic 0xbeef ..... > > It's kind of a wildcard that gets replaced with the number found in the > hardware. Nothing too special but probably unnecessary. > > Nico > _______________________________________________ > coreboot mailing list -- [email protected] > To unsubscribe send an email to [email protected] > >
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