[coreboot] patch: working SMP startup for kontron/core2

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Mon Mar 9 03:07:24 CET 2009

On 07.03.2009 16:37, ron minnich wrote:
> On Sat, Mar 7, 2009 at 2:05 AM, Peter Stuge <peter at stuge.se> wrote:
>>> +     movw    $0x11, 0
>> Just curious, what do these movws to 0 do?
> Glad you asked! These are how I got it debugged. Since we have another
> CPU (BSP) I had the BSP wait and print out the values. These are POST
> codes for AP startup! So BSP can now monitor AP progress with
> variables -- no more "worked"/"did not work" but "here's how far it
> got". The BSP has far more knowledge than in v2 of how far things got.
> They movw to 0 going to be removed, I think; we can depend on
> secondary.S. Or should we? Should I leave them in?

Please leave them in! More diagnostics are always welcome. If would be
nice to be able to determine the AP core ID somehow from the AP POST
code. You already use 4 bytes for that purpose. The first 2 bytes have a
0-extended POST code, the second 2 bytes have 0xbeef.



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