On Tue, Apr 10, 2012 at 5:29 AM, Bao, Zheng Zheng.Bao@amd.com wrote:
I tried. It behaves as bad as wbinvd does.
Joe
-----Original Message----- From: Andrew Goodbody [mailto:ajg4tadpole@gmail.com] Sent: Tuesday, April 10, 2012 7:04 PM To: Bao, Zheng Cc: 'Marc Jones'; Marc Jones; 'coreboot@coreboot.org' Subject: Re: [coreboot] Patch merged into coreboot/master: c35c461 Invalidate cache before first jump
On 09/04/12 04:24, Bao, Zheng wrote:
Hi, It is unstable. In most cases, it hangs at this wbinvd. Once it pass
that instruction, it will hang at when AP cores are launched.
Try invd instead of wbinvd. There should be no need to preserve anything from the cache so the write back is not needed. The write back may also need functional memory which will not be there at least from power on. Also note that these instructions are 486+ only.
Andrew
An wbind/invd by the APs may to cause problems with CAR. I think that the coherency rules will cause a wbind on all cores, but I am not positive.
Stefan, can you explain the requirement or consider how else to only do this on a processor that requires it?
Marc